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/tcp.h>
  57 #include <linux/if_arp.h>
  58 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
  59 #include <net/datalink.h>
  60 #include <net/psnap.h>
  61 #include <net/sock.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(int 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         rt->dev     = devhint;
 577         rt->flags   = r->rt_flags;
 578         rt->gateway = ga->sat_addr;
 579
 580         retval = 0;
 581 out_unlock:
 582         write_unlock_bh(&atalk_routes_lock);
 583 out:
 584         return retval;
 585 }
 586
 587 /* Delete a route. Find it and discard it */
 588 static int atrtr_delete(struct atalk_addr * addr)
 589 {
 590         struct atalk_route **r = &atalk_routes;
 591         int retval = 0;
 592         struct atalk_route *tmp;
 593
 594         write_lock_bh(&atalk_routes_lock);
 595         while ((tmp = *r) != NULL) {
 596                 if (tmp->target.s_net == addr->s_net &&
 597                     (!(tmp->flags&RTF_GATEWAY) ||
 598                      tmp->target.s_node == addr->s_node)) {
 599                         *r = tmp->next;
 600                         dev_put(tmp->dev);
 601                         kfree(tmp);
 602                         goto out;
 603                 }
 604                 r = &tmp->next;
 605         }
 606         retval = -ENOENT;
 607 out:
 608         write_unlock_bh(&atalk_routes_lock);
 609         return retval;
 610 }
 611
 612 /*
 613  * Called when a device is downed. Just throw away any routes
 614  * via it.
 615  */
 616 static void atrtr_device_down(struct net_device *dev)
 617 {
 618         struct atalk_route **r = &atalk_routes;
 619         struct atalk_route *tmp;
 620
 621         write_lock_bh(&atalk_routes_lock);
 622         while ((tmp = *r) != NULL) {
 623                 if (tmp->dev == dev) {
 624                         *r = tmp->next;
 625                         dev_put(dev);
 626                         kfree(tmp);
 627                 } else
 628                         r = &tmp->next;
 629         }
 630         write_unlock_bh(&atalk_routes_lock);
 631
 632         if (atrtr_default.dev == dev)
 633                 atrtr_set_default(NULL);
 634 }
 635
 636 /* Actually down the interface */
 637 static inline void atalk_dev_down(struct net_device *dev)
 638 {
 639         atrtr_device_down(dev); /* Remove all routes for the device */
 640         aarp_device_down(dev);  /* Remove AARP entries for the device */
 641         atif_drop_device(dev);  /* Remove the device */
 642 }
 643
 644 /*
 645  * A device event has occurred. Watch for devices going down and
 646  * delete our use of them (iface and route).
 647  */
 648 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 649                             void *ptr)
 650 {
 651         if (event == NETDEV_DOWN)
 652                 /* Discard any use of this */
 653                 atalk_dev_down(ptr);
 654
 655         return NOTIFY_DONE;
 656 }
 657
 658 /* ioctl calls. Shouldn't even need touching */
 659 /* Device configuration ioctl calls */
 660 static int atif_ioctl(int cmd, void __user *arg)
 661 {
 662         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 663         struct ifreq atreq;
 664         struct atalk_netrange *nr;
 665         struct sockaddr_at *sa;
 666         struct net_device *dev;
 667         struct atalk_iface *atif;
 668         int ct;
 669         int limit;
 670         struct rtentry rtdef;
 671         int add_route;
 672
 673         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 674                 return -EFAULT;
 675
 676         dev = __dev_get_by_name(atreq.ifr_name);
 677         if (!dev)
 678                 return -ENODEV;
 679
 680         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 681         atif = atalk_find_dev(dev);
 682
 683         switch (cmd) {
 684                 case SIOCSIFADDR:
 685                         if (!capable(CAP_NET_ADMIN))
 686                                 return -EPERM;
 687                         if (sa->sat_family != AF_APPLETALK)
 688                                 return -EINVAL;
 689                         if (dev->type != ARPHRD_ETHER &&
 690                             dev->type != ARPHRD_LOOPBACK &&
 691                             dev->type != ARPHRD_LOCALTLK &&
 692                             dev->type != ARPHRD_PPP)
 693                                 return -EPROTONOSUPPORT;
 694
 695                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 696                         add_route = 1;
 697
 698                         /*
 699                          * if this is a point-to-point iface, and we already
 700                          * have an iface for this AppleTalk address, then we
 701                          * should not add a route
 702                          */
 703                         if ((dev->flags & IFF_POINTOPOINT) &&
 704                             atalk_find_interface(sa->sat_addr.s_net,
 705                                                  sa->sat_addr.s_node)) {
 706                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 707                                                   "interface added with "
 708                                                   "existing address\n");
 709                                 add_route = 0;
 710                         }
 711
 712                         /*
 713                          * Phase 1 is fine on LocalTalk but we don't do
 714                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 715                          */
 716                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 717                                 return -EPROTONOSUPPORT;
 718                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 719                             sa->sat_addr.s_node == 254)
 720                                 return -EINVAL;
 721                         if (atif) {
 722                                 /* Already setting address */
 723                                 if (atif->status & ATIF_PROBE)
 724                                         return -EBUSY;
 725
 726                                 atif->address.s_net  = sa->sat_addr.s_net;
 727                                 atif->address.s_node = sa->sat_addr.s_node;
 728                                 atrtr_device_down(dev); /* Flush old routes */
 729                         } else {
 730                                 atif = atif_add_device(dev, &sa->sat_addr);
 731                                 if (!atif)
 732                                         return -ENOMEM;
 733                         }
 734                         atif->nets = *nr;
 735
 736                         /*
 737                          * Check if the chosen address is used. If so we
 738                          * error and atalkd will try another.
 739                          */
 740
 741                         if (!(dev->flags & IFF_LOOPBACK) &&
 742                             !(dev->flags & IFF_POINTOPOINT) &&
 743                             atif_probe_device(atif) < 0) {
 744                                 atif_drop_device(dev);
 745                                 return -EADDRINUSE;
 746                         }
 747
 748                         /* Hey it worked - add the direct routes */
 749                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 750                         sa->sat_family = AF_APPLETALK;
 751                         sa->sat_addr.s_net  = atif->address.s_net;
 752                         sa->sat_addr.s_node = atif->address.s_node;
 753                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 754                         rtdef.rt_flags = RTF_UP;
 755                         sa->sat_family = AF_APPLETALK;
 756                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 757                         if (dev->flags & IFF_LOOPBACK ||
 758                             dev->flags & IFF_POINTOPOINT)
 759                                 rtdef.rt_flags |= RTF_HOST;
 760
 761                         /* Routerless initial state */
 762                         if (nr->nr_firstnet == htons(0) &&
 763                             nr->nr_lastnet == htons(0xFFFE)) {
 764                                 sa->sat_addr.s_net = atif->address.s_net;
 765                                 atrtr_create(&rtdef, dev);
 766                                 atrtr_set_default(dev);
 767                         } else {
 768                                 limit = ntohs(nr->nr_lastnet);
 769                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 770                                         printk(KERN_WARNING "Too many routes/"
 771                                                             "iface.\n");
 772                                         return -EINVAL;
 773                                 }
 774                                 if (add_route)
 775                                         for (ct = ntohs(nr->nr_firstnet);
 776                                              ct <= limit; ct++) {
 777                                                 sa->sat_addr.s_net = htons(ct);
 778                                                 atrtr_create(&rtdef, dev);
 779                                         }
 780                         }
 781                         dev_mc_add(dev, aarp_mcast, 6, 1);
 782                         return 0;
 783
 784                 case SIOCGIFADDR:
 785                         if (!atif)
 786                                 return -EADDRNOTAVAIL;
 787
 788                         sa->sat_family = AF_APPLETALK;
 789                         sa->sat_addr = atif->address;
 790                         break;
 791
 792                 case SIOCGIFBRDADDR:
 793                         if (!atif)
 794                                 return -EADDRNOTAVAIL;
 795
 796                         sa->sat_family = AF_APPLETALK;
 797                         sa->sat_addr.s_net = atif->address.s_net;
 798                         sa->sat_addr.s_node = ATADDR_BCAST;
 799                         break;
 800
 801                 case SIOCATALKDIFADDR:
 802                 case SIOCDIFADDR:
 803                         if (!capable(CAP_NET_ADMIN))
 804                                 return -EPERM;
 805                         if (sa->sat_family != AF_APPLETALK)
 806                                 return -EINVAL;
 807                         atalk_dev_down(dev);
 808                         break;
 809
 810                 case SIOCSARP:
 811                         if (!capable(CAP_NET_ADMIN))
 812                                 return -EPERM;
 813                         if (sa->sat_family != AF_APPLETALK)
 814                                 return -EINVAL;
 815                         if (!atif)
 816                                 return -EADDRNOTAVAIL;
 817
 818                         /*
 819                          * for now, we only support proxy AARP on ELAP;
 820                          * we should be able to do it for LocalTalk, too.
 821                          */
 822                         if (dev->type != ARPHRD_ETHER)
 823                                 return -EPROTONOSUPPORT;
 824
 825                         /*
 826                          * atif points to the current interface on this network;
 827                          * we aren't concerned about its current status (at
 828                          * least for now), but it has all the settings about
 829                          * the network we're going to probe. Consequently, it
 830                          * must exist.
 831                          */
 832                         if (!atif)
 833                                 return -EADDRNOTAVAIL;
 834
 835                         nr = (struct atalk_netrange *)&(atif->nets);
 836                         /*
 837                          * Phase 1 is fine on Localtalk but we don't do
 838                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 839                          */
 840                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 841                                 return -EPROTONOSUPPORT;
 842
 843                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 844                             sa->sat_addr.s_node == 254)
 845                                 return -EINVAL;
 846
 847                         /*
 848                          * Check if the chosen address is used. If so we
 849                          * error and ATCP will try another.
 850                          */
 851                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 852                                 return -EADDRINUSE;
 853
 854                         /*
 855                          * We now have an address on the local network, and
 856                          * the AARP code will defend it for us until we take it
 857                          * down. We don't set up any routes right now, because
 858                          * ATCP will install them manually via SIOCADDRT.
 859                          */
 860                         break;
 861
 862                 case SIOCDARP:
 863                         if (!capable(CAP_NET_ADMIN))
 864                                 return -EPERM;
 865                         if (sa->sat_family != AF_APPLETALK)
 866                                 return -EINVAL;
 867                         if (!atif)
 868                                 return -EADDRNOTAVAIL;
 869
 870                         /* give to aarp module to remove proxy entry */
 871                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 872                         return 0;
 873         }
 874
 875         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 876 }
 877
 878 /* Routing ioctl() calls */
 879 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 880 {
 881         struct rtentry rt;
 882
 883         if (copy_from_user(&rt, arg, sizeof(rt)))
 884                 return -EFAULT;
 885
 886         switch (cmd) {
 887                 case SIOCDELRT:
 888                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 889                                 return -EINVAL;
 890                         return atrtr_delete(&((struct sockaddr_at *)
 891                                                 &rt.rt_dst)->sat_addr);
 892
 893                 case SIOCADDRT: {
 894                         struct net_device *dev = NULL;
 895                         if (rt.rt_dev) {
 896                                 char name[IFNAMSIZ];
 897                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 898                                         return -EFAULT;
 899                                 name[IFNAMSIZ-1] = '\0';
 900                                 dev = __dev_get_by_name(name);
 901                                 if (!dev)
 902                                         return -ENODEV;
 903                         }
 904                         return atrtr_create(&rt, dev);
 905                 }
 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 <<= 1;
 928                 if (sum & 0x10000) {
 929                         sum++;
 930                         sum &= 0xffff;
 931                 }
 932                 data++;
 933         }
 934         return sum;
 935 }
 936
 937 /*  Checksum skb data --  similar to skb_checksum  */
 938 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 939                                    int len, unsigned long sum)
 940 {
 941         int start = skb_headlen(skb);
 942         int i, copy;
 943
 944         /* checksum stuff in header space */
 945         if ( (copy = start - offset) > 0) {
 946                 if (copy > len)
 947                         copy = len;
 948                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 949                 if ( (len -= copy) == 0)
 950                         return sum;
 951
 952                 offset += copy;
 953         }
 954
 955         /* checksum stuff in frags */
 956         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 957                 int end;
 958
 959                 BUG_TRAP(start <= offset + len);
 960
 961                 end = start + skb_shinfo(skb)->frags[i].size;
 962                 if ((copy = end - offset) > 0) {
 963                         u8 *vaddr;
 964                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 965
 966                         if (copy > len)
 967                                 copy = len;
 968                         vaddr = kmap_skb_frag(frag);
 969                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 970                                                   offset - start, copy, sum);
 971                         kunmap_skb_frag(vaddr);
 972
 973                         if (!(len -= copy))
 974                                 return sum;
 975                         offset += copy;
 976                 }
 977                 start = end;
 978         }
 979
 980         if (skb_shinfo(skb)->frag_list) {
 981                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
 982
 983                 for (; list; list = list->next) {
 984                         int end;
 985
 986                         BUG_TRAP(start <= offset + len);
 987
 988                         end = start + list->len;
 989                         if ((copy = end - offset) > 0) {
 990                                 if (copy > len)
 991                                         copy = len;
 992                                 sum = atalk_sum_skb(list, offset - start,
 993                                                     copy, sum);
 994                                 if ((len -= copy) == 0)
 995                                         return sum;
 996                                 offset += copy;
 997                         }
 998                         start = end;
 999                 }
1000         }
1001
1002         BUG_ON(len > 0);
1003
1004         return sum;
1005 }
1006
1007 static unsigned short atalk_checksum(const struct sk_buff *skb, int len)
1008 {
1009         unsigned long sum;
1010
1011         /* skip header 4 bytes */
1012         sum = atalk_sum_skb(skb, 4, len-4, 0);
1013
1014         /* Use 0xFFFF for 0. 0 itself means none */
1015         return sum ? htons((unsigned short)sum) : 0xFFFF;
1016 }
1017
1018 /*
1019  * Create a socket. Initialise the socket, blank the addresses
1020  * set the state.
1021  */
1022 static int atalk_create(struct socket *sock, int protocol)
1023 {
1024         struct sock *sk;
1025         struct atalk_sock *at;
1026         int rc = -ESOCKTNOSUPPORT;
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         rc = -ENOMEM;
1035         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, 1, NULL);
1036         if (!sk)
1037                 goto out;
1038         at = sk->sk_protinfo = kmalloc(sizeof(*at), GFP_KERNEL);
1039         if (!at)
1040                 goto outsk;
1041         memset(at, 0, sizeof(*at));
1042         rc = 0;
1043         sock->ops = &atalk_dgram_ops;
1044         sock_init_data(sock, sk);
1045         sk_set_owner(sk, THIS_MODULE);
1046
1047         /* Checksums on by default */
1048         sk->sk_zapped = 1;
1049 out:
1050         return rc;
1051 outsk:
1052         sk_free(sk);
1053         goto out;
1054 }
1055
1056 /* Free a socket. No work needed */
1057 static int atalk_release(struct socket *sock)
1058 {
1059         struct sock *sk = sock->sk;
1060
1061         if (sk) {
1062                 sock_orphan(sk);
1063                 sock->sk = NULL;
1064                 atalk_destroy_socket(sk);
1065         }
1066         return 0;
1067 }
1068
1069 /**
1070  * atalk_pick_and_bind_port - Pick a source port when one is not given
1071  * @sk - socket to insert into the tables
1072  * @sat - address to search for
1073  *
1074  * Pick a source port when one is not given. If we can find a suitable free
1075  * one, we insert the socket into the tables using it.
1076  *
1077  * This whole operation must be atomic.
1078  */
1079 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1080 {
1081         int retval;
1082
1083         write_lock_bh(&atalk_sockets_lock);
1084
1085         for (sat->sat_port = ATPORT_RESERVED;
1086              sat->sat_port < ATPORT_LAST;
1087              sat->sat_port++) {
1088                 struct sock *s;
1089                 struct hlist_node *node;
1090
1091                 sk_for_each(s, node, &atalk_sockets) {
1092                         struct atalk_sock *at = at_sk(s);
1093
1094                         if (at->src_net == sat->sat_addr.s_net &&
1095                             at->src_node == sat->sat_addr.s_node &&
1096                             at->src_port == sat->sat_port)
1097                                 goto try_next_port;
1098                 }
1099
1100                 /* Wheee, it's free, assign and insert. */
1101                 __atalk_insert_socket(sk);
1102                 at_sk(sk)->src_port = sat->sat_port;
1103                 retval = 0;
1104                 goto out;
1105
1106 try_next_port:;
1107         }
1108
1109         retval = -EBUSY;
1110 out:
1111         write_unlock_bh(&atalk_sockets_lock);
1112         return retval;
1113 }
1114
1115 static int atalk_autobind(struct sock *sk)
1116 {
1117         struct atalk_sock *at = at_sk(sk);
1118         struct sockaddr_at sat;
1119         struct atalk_addr *ap = atalk_find_primary();
1120         int n = -EADDRNOTAVAIL;
1121
1122         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1123                 goto out;
1124
1125         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1126         at->src_node = sat.sat_addr.s_node = ap->s_node;
1127
1128         n = atalk_pick_and_bind_port(sk, &sat);
1129         if (!n)
1130                 sk->sk_zapped = 0;
1131 out:
1132         return n;
1133 }
1134
1135 /* Set the address 'our end' of the connection */
1136 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1137 {
1138         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1139         struct sock *sk = sock->sk;
1140         struct atalk_sock *at = at_sk(sk);
1141
1142         if (!sk->sk_zapped || addr_len != sizeof(struct sockaddr_at))
1143                 return -EINVAL;
1144
1145         if (addr->sat_family != AF_APPLETALK)
1146                 return -EAFNOSUPPORT;
1147
1148         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1149                 struct atalk_addr *ap = atalk_find_primary();
1150
1151                 if (!ap)
1152                         return -EADDRNOTAVAIL;
1153
1154                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1155                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1156         } else {
1157                 if (!atalk_find_interface(addr->sat_addr.s_net,
1158                                           addr->sat_addr.s_node))
1159                         return -EADDRNOTAVAIL;
1160
1161                 at->src_net  = addr->sat_addr.s_net;
1162                 at->src_node = addr->sat_addr.s_node;
1163         }
1164
1165         if (addr->sat_port == ATADDR_ANYPORT) {
1166                 int n = atalk_pick_and_bind_port(sk, addr);
1167
1168                 if (n < 0)
1169                         return n;
1170         } else {
1171                 at->src_port = addr->sat_port;
1172
1173                 if (atalk_find_or_insert_socket(sk, addr))
1174                         return -EADDRINUSE;
1175         }
1176
1177         sk->sk_zapped = 0;
1178         return 0;
1179 }
1180
1181 /* Set the address we talk to */
1182 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1183                          int addr_len, int flags)
1184 {
1185         struct sock *sk = sock->sk;
1186         struct atalk_sock *at = at_sk(sk);
1187         struct sockaddr_at *addr;
1188
1189         sk->sk_state   = TCP_CLOSE;
1190         sock->state = SS_UNCONNECTED;
1191
1192         if (addr_len != sizeof(*addr))
1193                 return -EINVAL;
1194
1195         addr = (struct sockaddr_at *)uaddr;
1196
1197         if (addr->sat_family != AF_APPLETALK)
1198                 return -EAFNOSUPPORT;
1199
1200         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1201             !sock_flag(sk, SOCK_BROADCAST)) {
1202 #if 1
1203                 printk(KERN_WARNING "%s is broken and did not set "
1204                                     "SO_BROADCAST. It will break when 2.2 is "
1205                                     "released.\n",
1206                         current->comm);
1207 #else
1208                 return -EACCES;
1209 #endif
1210         }
1211
1212         if (sk->sk_zapped)
1213                 if (atalk_autobind(sk) < 0)
1214                         return -EBUSY;
1215
1216         if (!atrtr_get_dev(&addr->sat_addr))
1217                 return -ENETUNREACH;
1218
1219         at->dest_port = addr->sat_port;
1220         at->dest_net  = addr->sat_addr.s_net;
1221         at->dest_node = addr->sat_addr.s_node;
1222
1223         sock->state  = SS_CONNECTED;
1224         sk->sk_state = TCP_ESTABLISHED;
1225         return 0;
1226 }
1227
1228 /*
1229  * Find the name of an AppleTalk socket. Just copy the right
1230  * fields into the sockaddr.
1231  */
1232 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1233                          int *uaddr_len, int peer)
1234 {
1235         struct sockaddr_at sat;
1236         struct sock *sk = sock->sk;
1237         struct atalk_sock *at = at_sk(sk);
1238
1239         if (sk->sk_zapped)
1240                 if (atalk_autobind(sk) < 0)
1241                         return -ENOBUFS;
1242
1243         *uaddr_len = sizeof(struct sockaddr_at);
1244
1245         if (peer) {
1246                 if (sk->sk_state != TCP_ESTABLISHED)
1247                         return -ENOTCONN;
1248
1249                 sat.sat_addr.s_net  = at->dest_net;
1250                 sat.sat_addr.s_node = at->dest_node;
1251                 sat.sat_port        = at->dest_port;
1252         } else {
1253                 sat.sat_addr.s_net  = at->src_net;
1254                 sat.sat_addr.s_node = at->src_node;
1255                 sat.sat_port        = at->src_port;
1256         }
1257
1258         sat.sat_family = AF_APPLETALK;
1259         memcpy(uaddr, &sat, sizeof(sat));
1260         return 0;
1261 }
1262
1263 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1264 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1265 {
1266         return skb->data[12] == 22;
1267 }
1268
1269 static int handle_ip_over_ddp(struct sk_buff *skb)
1270 {
1271         struct net_device *dev = __dev_get_by_name("ipddp0");
1272         struct net_device_stats *stats;
1273
1274         /* This needs to be able to handle ipddp"N" devices */
1275         if (!dev)
1276                 return -ENODEV;
1277
1278         skb->protocol = htons(ETH_P_IP);
1279         skb_pull(skb, 13);
1280         skb->dev   = dev;
1281         skb->h.raw = skb->data;
1282
1283         stats = dev->priv;
1284         stats->rx_packets++;
1285         stats->rx_bytes += skb->len + 13;
1286         netif_rx(skb);  /* Send the SKB up to a higher place. */
1287         return 0;
1288 }
1289 #else
1290 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1291 #define is_ip_over_ddp(skb) 0
1292 #define handle_ip_over_ddp(skb) 0
1293 #endif
1294
1295 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1296                                struct ddpehdr *ddp, struct ddpebits *ddphv,
1297                                int origlen)
1298 {
1299         struct atalk_route *rt;
1300         struct atalk_addr ta;
1301
1302         /*
1303          * Don't route multicast, etc., packets, or packets sent to "this
1304          * network"
1305          */
1306         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1307                 /*
1308                  * FIXME:
1309                  *
1310                  * Can it ever happen that a packet is from a PPP iface and
1311                  * needs to be broadcast onto the default network?
1312                  */
1313                 if (dev->type == ARPHRD_PPP)
1314                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1315                                           "packet received from PPP iface\n");
1316                 goto free_it;
1317         }
1318
1319         ta.s_net  = ddp->deh_dnet;
1320         ta.s_node = ddp->deh_dnode;
1321
1322         /* Route the packet */
1323         rt = atrtr_find(&ta);
1324         if (!rt || ddphv->deh_hops == DDP_MAXHOPS)
1325                 goto free_it;
1326         /* FIXME: use skb->cb to be able to use shared skbs */
1327         ddphv->deh_hops++;
1328
1329         /*
1330          * Route goes through another gateway, so set the target to the
1331          * gateway instead.
1332          */
1333
1334         if (rt->flags & RTF_GATEWAY) {
1335                 ta.s_net  = rt->gateway.s_net;
1336                 ta.s_node = rt->gateway.s_node;
1337         }
1338
1339         /* Fix up skb->len field */
1340         skb_trim(skb, min_t(unsigned int, origlen,
1341                             (rt->dev->hard_header_len +
1342                              ddp_dl->header_length + ddphv->deh_len)));
1343
1344         /* Mend the byte order */
1345         /* FIXME: use skb->cb to be able to use shared skbs */
1346         *((__u16 *)ddp) = ntohs(*((__u16 *)ddphv));
1347
1348         /*
1349          * Send the buffer onwards
1350          *
1351          * Now we must always be careful. If it's come from LocalTalk to
1352          * EtherTalk it might not fit
1353          *
1354          * Order matters here: If a packet has to be copied to make a new
1355          * headroom (rare hopefully) then it won't need unsharing.
1356          *
1357          * Note. ddp-> becomes invalid at the realloc.
1358          */
1359         if (skb_headroom(skb) < 22) {
1360                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1361                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1362                 kfree_skb(skb);
1363                 if (!nskb)
1364                         goto out;
1365                 skb = nskb;
1366         } else
1367                 skb = skb_unshare(skb, GFP_ATOMIC);
1368
1369         /*
1370          * If the buffer didn't vanish into the lack of space bitbucket we can
1371          * send it.
1372          */
1373         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1374                 goto free_it;
1375 out:
1376         return;
1377 free_it:
1378         kfree_skb(skb);
1379 }
1380
1381 /**
1382  *      atalk_rcv - Receive a packet (in skb) from device dev
1383  *      @skb - packet received
1384  *      @dev - network device where the packet comes from
1385  *      @pt - packet type
1386  *
1387  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1388  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1389  *      header, skb->len is the DDP length. The physical headers have been
1390  *      extracted. PPP should probably pass frames marked as for this layer.
1391  *      [ie ARPHRD_ETHERTALK]
1392  */
1393 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1394                      struct packet_type *pt)
1395 {
1396         struct ddpehdr *ddp;
1397         struct sock *sock;
1398         struct atalk_iface *atif;
1399         struct sockaddr_at tosat;
1400         int origlen;
1401         struct ddpebits ddphv;
1402
1403         /* Don't mangle buffer if shared */
1404         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1405                 goto out;
1406
1407         /* Size check and make sure header is contiguous */
1408         if (!pskb_may_pull(skb, sizeof(*ddp)))
1409                 goto freeit;
1410
1411         ddp = ddp_hdr(skb);
1412
1413         /*
1414          *      Fix up the length field [Ok this is horrible but otherwise
1415          *      I end up with unions of bit fields and messy bit field order
1416          *      compiler/endian dependencies..]
1417          */
1418         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1419
1420         /* Trim buffer in case of stray trailing data */
1421         origlen = skb->len;
1422         skb_trim(skb, min_t(unsigned int, skb->len, ddphv.deh_len));
1423
1424         /*
1425          * Size check to see if ddp->deh_len was crap
1426          * (Otherwise we'll detonate most spectacularly
1427          * in the middle of recvmsg()).
1428          */
1429         if (skb->len < sizeof(*ddp))
1430                 goto freeit;
1431
1432         /*
1433          * Any checksums. Note we don't do htons() on this == is assumed to be
1434          * valid for net byte orders all over the networking code...
1435          */
1436         if (ddp->deh_sum &&
1437             atalk_checksum(skb, ddphv.deh_len) != ddp->deh_sum)
1438                 /* Not a valid AppleTalk frame - dustbin time */
1439                 goto freeit;
1440
1441         /* Check the packet is aimed at us */
1442         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1443                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1444         else
1445                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1446
1447         /* Not ours, so we route the packet via the correct AppleTalk iface */
1448         if (!atif) {
1449                 atalk_route_packet(skb, dev, ddp, &ddphv, origlen);
1450                 goto out;
1451         }
1452
1453         /* if IP over DDP is not selected this code will be optimized out */
1454         if (is_ip_over_ddp(skb))
1455                 return handle_ip_over_ddp(skb);
1456         /*
1457          * Which socket - atalk_search_socket() looks for a *full match*
1458          * of the <net, node, port> tuple.
1459          */
1460         tosat.sat_addr.s_net  = ddp->deh_dnet;
1461         tosat.sat_addr.s_node = ddp->deh_dnode;
1462         tosat.sat_port        = ddp->deh_dport;
1463
1464         sock = atalk_search_socket(&tosat, atif);
1465         if (!sock) /* But not one of our sockets */
1466                 goto freeit;
1467
1468         /* Queue packet (standard) */
1469         skb->sk = sock;
1470
1471         if (sock_queue_rcv_skb(sock, skb) < 0)
1472                 goto freeit;
1473 out:
1474         return 0;
1475 freeit:
1476         kfree_skb(skb);
1477         goto out;
1478 }
1479
1480 /*
1481  * Receive a LocalTalk frame. We make some demands on the caller here.
1482  * Caller must provide enough headroom on the packet to pull the short
1483  * header and append a long one.
1484  */
1485 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1486                         struct packet_type *pt)
1487 {
1488         /* Expand any short form frames */
1489         if (skb->mac.raw[2] == 1) {
1490                 struct ddpehdr *ddp;
1491                 /* Find our address */
1492                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1493
1494                 if (!ap || skb->len < sizeof(struct ddpshdr))
1495                         goto freeit;
1496
1497                 /* Don't mangle buffer if shared */
1498                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1499                         return 0;
1500
1501                 /*
1502                  * The push leaves us with a ddephdr not an shdr, and
1503                  * handily the port bytes in the right place preset.
1504                  */
1505                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1506
1507                 /* Now fill in the long header */
1508
1509                 /*
1510                  * These two first. The mac overlays the new source/dest
1511                  * network information so we MUST copy these before
1512                  * we write the network numbers !
1513                  */
1514
1515                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1516                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1517
1518                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1519                 ddp->deh_snet  = ap->s_net;
1520                 ddp->deh_sum   = 0;             /* No checksum */
1521                 /*
1522                  * Not sure about this bit...
1523                  */
1524                 ddp->deh_len   = skb->len;
1525                 ddp->deh_hops  = DDP_MAXHOPS;   /* Non routable, so force a drop
1526                                                    if we slip up later */
1527                 /* Mend the byte order */
1528                 *((__u16 *)ddp) = htons(*((__u16 *)ddp));
1529         }
1530         skb->h.raw = skb->data;
1531
1532         return atalk_rcv(skb, dev, pt);
1533 freeit:
1534         kfree_skb(skb);
1535         return 0;
1536 }
1537
1538 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1539                          size_t len)
1540 {
1541         struct sock *sk = sock->sk;
1542         struct atalk_sock *at = at_sk(sk);
1543         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1544         int flags = msg->msg_flags;
1545         int loopback = 0;
1546         struct sockaddr_at local_satalk, gsat;
1547         struct sk_buff *skb;
1548         struct net_device *dev;
1549         struct ddpehdr *ddp;
1550         int size;
1551         struct atalk_route *rt;
1552         int err;
1553
1554         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1555                 return -EINVAL;
1556
1557         if (len > DDP_MAXSZ)
1558                 return -EMSGSIZE;
1559
1560         if (usat) {
1561                 if (sk->sk_zapped)
1562                         if (atalk_autobind(sk) < 0)
1563                                 return -EBUSY;
1564
1565                 if (msg->msg_namelen < sizeof(*usat) ||
1566                     usat->sat_family != AF_APPLETALK)
1567                         return -EINVAL;
1568
1569                 /* netatalk doesn't implement this check */
1570                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1571                     !sock_flag(sk, SOCK_BROADCAST)) {
1572                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1573                                          "it will break before 2.2\n");
1574 #if 0
1575                         return -EPERM;
1576 #endif
1577                 }
1578         } else {
1579                 if (sk->sk_state != TCP_ESTABLISHED)
1580                         return -ENOTCONN;
1581                 usat = &local_satalk;
1582                 usat->sat_family      = AF_APPLETALK;
1583                 usat->sat_port        = at->dest_port;
1584                 usat->sat_addr.s_node = at->dest_node;
1585                 usat->sat_addr.s_net  = at->dest_net;
1586         }
1587
1588         /* Build a packet */
1589         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1590
1591         /* For headers */
1592         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1593
1594         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1595                 rt = atrtr_find(&usat->sat_addr);
1596                 if (!rt)
1597                         return -ENETUNREACH;
1598
1599                 dev = rt->dev;
1600         } else {
1601                 struct atalk_addr at_hint;
1602
1603                 at_hint.s_node = 0;
1604                 at_hint.s_net  = at->src_net;
1605
1606                 rt = atrtr_find(&at_hint);
1607                 if (!rt)
1608                         return -ENETUNREACH;
1609
1610                 dev = rt->dev;
1611         }
1612
1613         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1614                         sk, size, dev->name);
1615
1616         size += dev->hard_header_len;
1617         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1618         if (!skb)
1619                 return err;
1620
1621         skb->sk = sk;
1622         skb_reserve(skb, ddp_dl->header_length);
1623         skb_reserve(skb, dev->hard_header_len);
1624         skb->dev = dev;
1625
1626         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1627
1628         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1629         ddp->deh_pad  = 0;
1630         ddp->deh_hops = 0;
1631         ddp->deh_len  = len + sizeof(*ddp);
1632         /*
1633          * Fix up the length field [Ok this is horrible but otherwise
1634          * I end up with unions of bit fields and messy bit field order
1635          * compiler/endian dependencies..
1636          */
1637         *((__u16 *)ddp) = ntohs(*((__u16 *)ddp));
1638
1639         ddp->deh_dnet  = usat->sat_addr.s_net;
1640         ddp->deh_snet  = at->src_net;
1641         ddp->deh_dnode = usat->sat_addr.s_node;
1642         ddp->deh_snode = at->src_node;
1643         ddp->deh_dport = usat->sat_port;
1644         ddp->deh_sport = at->src_port;
1645
1646         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1647
1648         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1649         if (err) {
1650                 kfree_skb(skb);
1651                 return -EFAULT;
1652         }
1653
1654         if (sk->sk_no_check == 1)
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                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1670                         if (aarp_send_ddp(dev, skb2,
1671                                           &usat->sat_addr, NULL) == -1)
1672                                 kfree_skb(skb2);
1673                                 /* else queued/sent above in the aarp queue */
1674                 }
1675         }
1676
1677         if (dev->flags & IFF_LOOPBACK || loopback) {
1678                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1679                 /* loop back */
1680                 skb_orphan(skb);
1681                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1682         } else {
1683                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1684                 if (rt->flags & RTF_GATEWAY) {
1685                     gsat.sat_addr = rt->gateway;
1686                     usat = &gsat;
1687                 }
1688
1689                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1690                         kfree_skb(skb);
1691                 /* else queued/sent above in the aarp queue */
1692         }
1693         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1694
1695         return len;
1696 }
1697
1698 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1699                          size_t size, int flags)
1700 {
1701         struct sock *sk = sock->sk;
1702         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1703         struct ddpehdr *ddp;
1704         int copied = 0;
1705         int err = 0;
1706         struct ddpebits ddphv;
1707         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1708                                                 flags & MSG_DONTWAIT, &err);
1709         if (!skb)
1710                 return err;
1711
1712         /* FIXME: use skb->cb to be able to use shared skbs */
1713         ddp = ddp_hdr(skb);
1714         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1715
1716         if (sk->sk_type == SOCK_RAW) {
1717                 copied = ddphv.deh_len;
1718                 if (copied > size) {
1719                         copied = size;
1720                         msg->msg_flags |= MSG_TRUNC;
1721                 }
1722
1723                 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1724         } else {
1725                 copied = ddphv.deh_len - sizeof(*ddp);
1726                 if (copied > size) {
1727                         copied = size;
1728                         msg->msg_flags |= MSG_TRUNC;
1729                 }
1730                 err = skb_copy_datagram_iovec(skb, sizeof(*ddp),
1731                                               msg->msg_iov, copied);
1732         }
1733
1734         if (!err) {
1735                 if (sat) {
1736                         sat->sat_family      = AF_APPLETALK;
1737                         sat->sat_port        = ddp->deh_sport;
1738                         sat->sat_addr.s_node = ddp->deh_snode;
1739                         sat->sat_addr.s_net  = ddp->deh_snet;
1740                 }
1741                 msg->msg_namelen = sizeof(*sat);
1742         }
1743
1744         skb_free_datagram(sk, skb);     /* Free the datagram. */
1745         return err ? : copied;
1746 }
1747
1748
1749 /*
1750  * AppleTalk ioctl calls.
1751  */
1752 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1753 {
1754         int rc = -EINVAL;
1755         struct sock *sk = sock->sk;
1756         void __user *argp = (void __user *)arg;
1757
1758         switch (cmd) {
1759                 /* Protocol layer */
1760                 case TIOCOUTQ: {
1761                         long amount = sk->sk_sndbuf -
1762                                       atomic_read(&sk->sk_wmem_alloc);
1763
1764                         if (amount < 0)
1765                                 amount = 0;
1766                         rc = put_user(amount, (int __user *)argp);
1767                         break;
1768                 }
1769                 case TIOCINQ: {
1770                         /*
1771                          * These two are safe on a single CPU system as only
1772                          * user tasks fiddle here
1773                          */
1774                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1775                         long amount = 0;
1776
1777                         if (skb)
1778                                 amount = skb->len - sizeof(struct ddpehdr);
1779                         rc = put_user(amount, (int __user *)argp);
1780                         break;
1781                 }
1782                 case SIOCGSTAMP:
1783                         rc = sock_get_timestamp(sk, argp);
1784                         break;
1785                 /* Routing */
1786                 case SIOCADDRT:
1787                 case SIOCDELRT:
1788                         rc = -EPERM;
1789                         if (capable(CAP_NET_ADMIN))
1790                                 rc = atrtr_ioctl(cmd, argp);
1791                         break;
1792                 /* Interface */
1793                 case SIOCGIFADDR:
1794                 case SIOCSIFADDR:
1795                 case SIOCGIFBRDADDR:
1796                 case SIOCATALKDIFADDR:
1797                 case SIOCDIFADDR:
1798                 case SIOCSARP:          /* proxy AARP */
1799                 case SIOCDARP:          /* proxy AARP */
1800                         rtnl_lock();
1801                         rc = atif_ioctl(cmd, argp);
1802                         rtnl_unlock();
1803                         break;
1804                 /* Physical layer ioctl calls */
1805                 case SIOCSIFLINK:
1806                 case SIOCGIFHWADDR:
1807                 case SIOCSIFHWADDR:
1808                 case SIOCGIFFLAGS:
1809                 case SIOCSIFFLAGS:
1810                 case SIOCGIFTXQLEN:
1811                 case SIOCSIFTXQLEN:
1812                 case SIOCGIFMTU:
1813                 case SIOCGIFCONF:
1814                 case SIOCADDMULTI:
1815                 case SIOCDELMULTI:
1816                 case SIOCGIFCOUNT:
1817                 case SIOCGIFINDEX:
1818                 case SIOCGIFNAME:
1819                         rc = dev_ioctl(cmd, argp);
1820                         break;
1821         }
1822
1823         return rc;
1824 }
1825
1826 static struct net_proto_family atalk_family_ops = {
1827         .family         = PF_APPLETALK,
1828         .create         = atalk_create,
1829         .owner          = THIS_MODULE,
1830 };
1831
1832 static struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1833         .family         = PF_APPLETALK,
1834         .owner          = THIS_MODULE,
1835         .release        = atalk_release,
1836         .bind           = atalk_bind,
1837         .connect        = atalk_connect,
1838         .socketpair     = sock_no_socketpair,
1839         .accept         = sock_no_accept,
1840         .getname        = atalk_getname,
1841         .poll           = datagram_poll,
1842         .ioctl          = atalk_ioctl,
1843         .listen         = sock_no_listen,
1844         .shutdown       = sock_no_shutdown,
1845         .setsockopt     = sock_no_setsockopt,
1846         .getsockopt     = sock_no_getsockopt,
1847         .sendmsg        = atalk_sendmsg,
1848         .recvmsg        = atalk_recvmsg,
1849         .mmap           = sock_no_mmap,
1850         .sendpage       = sock_no_sendpage,
1851 };
1852
1853 #include <linux/smp_lock.h>
1854 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1855
1856 static struct notifier_block ddp_notifier = {
1857         .notifier_call  = ddp_device_event,
1858 };
1859
1860 static struct packet_type ltalk_packet_type = {
1861         .type           = __constant_htons(ETH_P_LOCALTALK),
1862         .func           = ltalk_rcv,
1863 };
1864
1865 static struct packet_type ppptalk_packet_type = {
1866         .type           = __constant_htons(ETH_P_PPPTALK),
1867         .func           = atalk_rcv,
1868 };
1869
1870 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1871
1872 /* Export symbols for use by drivers when AppleTalk is a module */
1873 EXPORT_SYMBOL(aarp_send_ddp);
1874 EXPORT_SYMBOL(atrtr_get_dev);
1875 EXPORT_SYMBOL(atalk_find_dev_addr);
1876
1877 static char atalk_err_snap[] __initdata =
1878         KERN_CRIT "Unable to register DDP with SNAP.\n";
1879
1880 /* Called by proto.c on kernel start up */
1881 static int __init atalk_init(void)
1882 {
1883         (void)sock_register(&atalk_family_ops);
1884         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1885         if (!ddp_dl)
1886                 printk(atalk_err_snap);
1887
1888         dev_add_pack(&ltalk_packet_type);
1889         dev_add_pack(&ppptalk_packet_type);
1890
1891         register_netdevice_notifier(&ddp_notifier);
1892         aarp_proto_init();
1893         atalk_proc_init();
1894         atalk_register_sysctl();
1895         return 0;
1896 }
1897 module_init(atalk_init);
1898
1899 /*
1900  * No explicit module reference count manipulation is needed in the
1901  * protocol. Socket layer sets module reference count for us
1902  * and interfaces reference counting is done
1903  * by the network device layer.
1904  *
1905  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1906  * sockets be closed from user space.
1907  */
1908 static void __exit atalk_exit(void)
1909 {
1910 #ifdef CONFIG_SYSCTL
1911         atalk_unregister_sysctl();
1912 #endif /* CONFIG_SYSCTL */
1913         atalk_proc_exit();
1914         aarp_cleanup_module();  /* General aarp clean-up. */
1915         unregister_netdevice_notifier(&ddp_notifier);
1916         dev_remove_pack(&ltalk_packet_type);
1917         dev_remove_pack(&ppptalk_packet_type);
1918         unregister_snap_client(ddp_dl);
1919         sock_unregister(PF_APPLETALK);
1920 }
1921 module_exit(atalk_exit);
1922
1923 MODULE_LICENSE("GPL");
1924 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1925 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1926 MODULE_ALIAS_NETPROTO(PF_APPLETALK);