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/capability.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 #include "../core/kmap_skb.h"
  65
  66 struct datalink_proto *ddp_dl, *aarp_dl;
  67 static const struct proto_ops atalk_dgram_ops;
  68
  69 /**************************************************************************\
  70 *                                                                          *
  71 * Handlers for the socket list.                                            *
  72 *                                                                          *
  73 \**************************************************************************/
  74
  75 HLIST_HEAD(atalk_sockets);
  76 DEFINE_RWLOCK(atalk_sockets_lock);
  77
  78 static inline void __atalk_insert_socket(struct sock *sk)
  79 {
  80         sk_add_node(sk, &atalk_sockets);
  81 }
  82
  83 static inline void atalk_remove_socket(struct sock *sk)
  84 {
  85         write_lock_bh(&atalk_sockets_lock);
  86         sk_del_node_init(sk);
  87         write_unlock_bh(&atalk_sockets_lock);
  88 }
  89
  90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  91                                         struct atalk_iface *atif)
  92 {
  93         struct sock *s;
  94         struct hlist_node *node;
  95
  96         read_lock_bh(&atalk_sockets_lock);
  97         sk_for_each(s, node, &atalk_sockets) {
  98                 struct atalk_sock *at = at_sk(s);
  99
 100                 if (to->sat_port != at->src_port)
 101                         continue;
 102
 103                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 104                     to->sat_addr.s_node == ATADDR_BCAST)
 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 = kzalloc(sizeof(*iface), GFP_KERNEL);
 232
 233         if (!iface)
 234                 goto out;
 235
 236         dev_hold(dev);
 237         iface->dev = dev;
 238         dev->atalk_ptr = iface;
 239         iface->address = *sa;
 240         iface->status = 0;
 241
 242         write_lock_bh(&atalk_interfaces_lock);
 243         iface->next = atalk_interfaces;
 244         atalk_interfaces = iface;
 245         write_unlock_bh(&atalk_interfaces_lock);
 246 out:
 247         return iface;
 248 }
 249
 250 /* Perform phase 2 AARP probing on our tentative address */
 251 static int atif_probe_device(struct atalk_iface *atif)
 252 {
 253         int netrange = ntohs(atif->nets.nr_lastnet) -
 254                         ntohs(atif->nets.nr_firstnet) + 1;
 255         int probe_net = ntohs(atif->address.s_net);
 256         int probe_node = atif->address.s_node;
 257         int netct, nodect;
 258
 259         /* Offset the network we start probing with */
 260         if (probe_net == ATADDR_ANYNET) {
 261                 probe_net = ntohs(atif->nets.nr_firstnet);
 262                 if (netrange)
 263                         probe_net += jiffies % netrange;
 264         }
 265         if (probe_node == ATADDR_ANYNODE)
 266                 probe_node = jiffies & 0xFF;
 267
 268         /* Scan the networks */
 269         atif->status |= ATIF_PROBE;
 270         for (netct = 0; netct <= netrange; netct++) {
 271                 /* Sweep the available nodes from a given start */
 272                 atif->address.s_net = htons(probe_net);
 273                 for (nodect = 0; nodect < 256; nodect++) {
 274                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 275                         if (atif->address.s_node > 0 &&
 276                             atif->address.s_node < 254) {
 277                                 /* Probe a proposed address */
 278                                 aarp_probe_network(atif);
 279
 280                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 281                                         atif->status &= ~ATIF_PROBE;
 282                                         return 0;
 283                                 }
 284                         }
 285                         atif->status &= ~ATIF_PROBE_FAIL;
 286                 }
 287                 probe_net++;
 288                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 289                         probe_net = ntohs(atif->nets.nr_firstnet);
 290         }
 291         atif->status &= ~ATIF_PROBE;
 292
 293         return -EADDRINUSE;     /* Network is full... */
 294 }
 295
 296
 297 /* Perform AARP probing for a proxy address */
 298 static int atif_proxy_probe_device(struct atalk_iface *atif,
 299                                    struct atalk_addr* proxy_addr)
 300 {
 301         int netrange = ntohs(atif->nets.nr_lastnet) -
 302                         ntohs(atif->nets.nr_firstnet) + 1;
 303         /* we probe the interface's network */
 304         int probe_net = ntohs(atif->address.s_net);
 305         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 306         int netct, nodect;
 307
 308         /* Offset the network we start probing with */
 309         if (probe_net == ATADDR_ANYNET) {
 310                 probe_net = ntohs(atif->nets.nr_firstnet);
 311                 if (netrange)
 312                         probe_net += jiffies % netrange;
 313         }
 314
 315         if (probe_node == ATADDR_ANYNODE)
 316                 probe_node = jiffies & 0xFF;
 317
 318         /* Scan the networks */
 319         for (netct = 0; netct <= netrange; netct++) {
 320                 /* Sweep the available nodes from a given start */
 321                 proxy_addr->s_net = htons(probe_net);
 322                 for (nodect = 0; nodect < 256; nodect++) {
 323                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 324                         if (proxy_addr->s_node > 0 &&
 325                             proxy_addr->s_node < 254) {
 326                                 /* Tell AARP to probe a proposed address */
 327                                 int ret = aarp_proxy_probe_network(atif,
 328                                                                     proxy_addr);
 329
 330                                 if (ret != -EADDRINUSE)
 331                                         return ret;
 332                         }
 333                 }
 334                 probe_net++;
 335                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 336                         probe_net = ntohs(atif->nets.nr_firstnet);
 337         }
 338
 339         return -EADDRINUSE;     /* Network is full... */
 340 }
 341
 342
 343 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 344 {
 345         struct atalk_iface *iface = dev->atalk_ptr;
 346         return iface ? &iface->address : NULL;
 347 }
 348
 349 static struct atalk_addr *atalk_find_primary(void)
 350 {
 351         struct atalk_iface *fiface = NULL;
 352         struct atalk_addr *retval;
 353         struct atalk_iface *iface;
 354
 355         /*
 356          * Return a point-to-point interface only if
 357          * there is no non-ptp interface available.
 358          */
 359         read_lock_bh(&atalk_interfaces_lock);
 360         for (iface = atalk_interfaces; iface; iface = iface->next) {
 361                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 362                         fiface = iface;
 363                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 364                         retval = &iface->address;
 365                         goto out;
 366                 }
 367         }
 368
 369         if (fiface)
 370                 retval = &fiface->address;
 371         else if (atalk_interfaces)
 372                 retval = &atalk_interfaces->address;
 373         else
 374                 retval = NULL;
 375 out:
 376         read_unlock_bh(&atalk_interfaces_lock);
 377         return retval;
 378 }
 379
 380 /*
 381  * Find a match for 'any network' - ie any of our interfaces with that
 382  * node number will do just nicely.
 383  */
 384 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 385 {
 386         struct atalk_iface *iface = dev->atalk_ptr;
 387
 388         if (!iface || iface->status & ATIF_PROBE)
 389                 goto out_err;
 390
 391         if (node != ATADDR_BCAST &&
 392             iface->address.s_node != node &&
 393             node != ATADDR_ANYNODE)
 394                 goto out_err;
 395 out:
 396         return iface;
 397 out_err:
 398         iface = NULL;
 399         goto out;
 400 }
 401
 402 /* Find a match for a specific network:node pair */
 403 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 404 {
 405         struct atalk_iface *iface;
 406
 407         read_lock_bh(&atalk_interfaces_lock);
 408         for (iface = atalk_interfaces; iface; iface = iface->next) {
 409                 if ((node == ATADDR_BCAST ||
 410                      node == ATADDR_ANYNODE ||
 411                      iface->address.s_node == node) &&
 412                     iface->address.s_net == net &&
 413                     !(iface->status & ATIF_PROBE))
 414                         break;
 415
 416                 /* XXXX.0 -- net.0 returns the iface associated with net */
 417                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 418                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 419                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 420                         break;
 421         }
 422         read_unlock_bh(&atalk_interfaces_lock);
 423         return iface;
 424 }
 425
 426
 427 /*
 428  * Find a route for an AppleTalk packet. This ought to get cached in
 429  * the socket (later on...). We know about host routes and the fact
 430  * that a route must be direct to broadcast.
 431  */
 432 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 433 {
 434         /*
 435          * we must search through all routes unless we find a
 436          * host route, because some host routes might overlap
 437          * network routes
 438          */
 439         struct atalk_route *net_route = NULL;
 440         struct atalk_route *r;
 441
 442         read_lock_bh(&atalk_routes_lock);
 443         for (r = atalk_routes; r; r = r->next) {
 444                 if (!(r->flags & RTF_UP))
 445                         continue;
 446
 447                 if (r->target.s_net == target->s_net) {
 448                         if (r->flags & RTF_HOST) {
 449                                 /*
 450                                  * if this host route is for the target,
 451                                  * the we're done
 452                                  */
 453                                 if (r->target.s_node == target->s_node)
 454                                         goto out;
 455                         } else
 456                                 /*
 457                                  * this route will work if there isn't a
 458                                  * direct host route, so cache it
 459                                  */
 460                                 net_route = r;
 461                 }
 462         }
 463
 464         /*
 465          * if we found a network route but not a direct host
 466          * route, then return it
 467          */
 468         if (net_route)
 469                 r = net_route;
 470         else if (atrtr_default.dev)
 471                 r = &atrtr_default;
 472         else /* No route can be found */
 473                 r = NULL;
 474 out:
 475         read_unlock_bh(&atalk_routes_lock);
 476         return r;
 477 }
 478
 479
 480 /*
 481  * Given an AppleTalk network, find the device to use. This can be
 482  * a simple lookup.
 483  */
 484 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 485 {
 486         struct atalk_route *atr = atrtr_find(sa);
 487         return atr ? atr->dev : NULL;
 488 }
 489
 490 /* Set up a default router */
 491 static void atrtr_set_default(struct net_device *dev)
 492 {
 493         atrtr_default.dev            = dev;
 494         atrtr_default.flags          = RTF_UP;
 495         atrtr_default.gateway.s_net  = htons(0);
 496         atrtr_default.gateway.s_node = 0;
 497 }
 498
 499 /*
 500  * Add a router. Basically make sure it looks valid and stuff the
 501  * entry in the list. While it uses netranges we always set them to one
 502  * entry to work like netatalk.
 503  */
 504 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 505 {
 506         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 507         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 508         struct atalk_route *rt;
 509         struct atalk_iface *iface, *riface;
 510         int retval = -EINVAL;
 511
 512         /*
 513          * Fixme: Raise/Lower a routing change semaphore for these
 514          * operations.
 515          */
 516
 517         /* Validate the request */
 518         if (ta->sat_family != AF_APPLETALK ||
 519             (!devhint && ga->sat_family != AF_APPLETALK))
 520                 goto out;
 521
 522         /* Now walk the routing table and make our decisions */
 523         write_lock_bh(&atalk_routes_lock);
 524         for (rt = atalk_routes; rt; rt = rt->next) {
 525                 if (r->rt_flags != rt->flags)
 526                         continue;
 527
 528                 if (ta->sat_addr.s_net == rt->target.s_net) {
 529                         if (!(rt->flags & RTF_HOST))
 530                                 break;
 531                         if (ta->sat_addr.s_node == rt->target.s_node)
 532                                 break;
 533                 }
 534         }
 535
 536         if (!devhint) {
 537                 riface = NULL;
 538
 539                 read_lock_bh(&atalk_interfaces_lock);
 540                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 541                         if (!riface &&
 542                             ntohs(ga->sat_addr.s_net) >=
 543                                         ntohs(iface->nets.nr_firstnet) &&
 544                             ntohs(ga->sat_addr.s_net) <=
 545                                         ntohs(iface->nets.nr_lastnet))
 546                                 riface = iface;
 547
 548                         if (ga->sat_addr.s_net == iface->address.s_net &&
 549                             ga->sat_addr.s_node == iface->address.s_node)
 550                                 riface = iface;
 551                 }
 552                 read_unlock_bh(&atalk_interfaces_lock);
 553
 554                 retval = -ENETUNREACH;
 555                 if (!riface)
 556                         goto out_unlock;
 557
 558                 devhint = riface->dev;
 559         }
 560
 561         if (!rt) {
 562                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 563
 564                 retval = -ENOBUFS;
 565                 if (!rt)
 566                         goto out_unlock;
 567
 568                 rt->next = atalk_routes;
 569                 atalk_routes = rt;
 570         }
 571
 572         /* Fill in the routing entry */
 573         rt->target  = ta->sat_addr;
 574         dev_hold(devhint);
 575         rt->dev     = devhint;
 576         rt->flags   = r->rt_flags;
 577         rt->gateway = ga->sat_addr;
 578
 579         retval = 0;
 580 out_unlock:
 581         write_unlock_bh(&atalk_routes_lock);
 582 out:
 583         return retval;
 584 }
 585
 586 /* Delete a route. Find it and discard it */
 587 static int atrtr_delete(struct atalk_addr * addr)
 588 {
 589         struct atalk_route **r = &atalk_routes;
 590         int retval = 0;
 591         struct atalk_route *tmp;
 592
 593         write_lock_bh(&atalk_routes_lock);
 594         while ((tmp = *r) != NULL) {
 595                 if (tmp->target.s_net == addr->s_net &&
 596                     (!(tmp->flags&RTF_GATEWAY) ||
 597                      tmp->target.s_node == addr->s_node)) {
 598                         *r = tmp->next;
 599                         dev_put(tmp->dev);
 600                         kfree(tmp);
 601                         goto out;
 602                 }
 603                 r = &tmp->next;
 604         }
 605         retval = -ENOENT;
 606 out:
 607         write_unlock_bh(&atalk_routes_lock);
 608         return retval;
 609 }
 610
 611 /*
 612  * Called when a device is downed. Just throw away any routes
 613  * via it.
 614  */
 615 static void atrtr_device_down(struct net_device *dev)
 616 {
 617         struct atalk_route **r = &atalk_routes;
 618         struct atalk_route *tmp;
 619
 620         write_lock_bh(&atalk_routes_lock);
 621         while ((tmp = *r) != NULL) {
 622                 if (tmp->dev == dev) {
 623                         *r = tmp->next;
 624                         dev_put(dev);
 625                         kfree(tmp);
 626                 } else
 627                         r = &tmp->next;
 628         }
 629         write_unlock_bh(&atalk_routes_lock);
 630
 631         if (atrtr_default.dev == dev)
 632                 atrtr_set_default(NULL);
 633 }
 634
 635 /* Actually down the interface */
 636 static inline void atalk_dev_down(struct net_device *dev)
 637 {
 638         atrtr_device_down(dev); /* Remove all routes for the device */
 639         aarp_device_down(dev);  /* Remove AARP entries for the device */
 640         atif_drop_device(dev);  /* Remove the device */
 641 }
 642
 643 /*
 644  * A device event has occurred. Watch for devices going down and
 645  * delete our use of them (iface and route).
 646  */
 647 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 648                             void *ptr)
 649 {
 650         struct net_device *dev = ptr;
 651
 652         if (event == NETDEV_DOWN)
 653                 /* Discard any use of this */
 654                 atalk_dev_down(dev);
 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 __be16 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) : htons(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 net *net, struct socket *sock, int protocol)
1030 {
1031         struct sock *sk;
1032         int rc = -ESOCKTNOSUPPORT;
1033
1034         if (net != &init_net)
1035                 return -EAFNOSUPPORT;
1036
1037         /*
1038          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1039          * and gives you the full ELAP frame. Should be handy for CAP 8)
1040          */
1041         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1042                 goto out;
1043         rc = -ENOMEM;
1044         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1045         if (!sk)
1046                 goto out;
1047         rc = 0;
1048         sock->ops = &atalk_dgram_ops;
1049         sock_init_data(sock, sk);
1050
1051         /* Checksums on by default */
1052         sock_set_flag(sk, SOCK_ZAPPED);
1053 out:
1054         return rc;
1055 }
1056
1057 /* Free a socket. No work needed */
1058 static int atalk_release(struct socket *sock)
1059 {
1060         struct sock *sk = sock->sk;
1061
1062         if (sk) {
1063                 sock_orphan(sk);
1064                 sock->sk = NULL;
1065                 atalk_destroy_socket(sk);
1066         }
1067         return 0;
1068 }
1069
1070 /**
1071  * atalk_pick_and_bind_port - Pick a source port when one is not given
1072  * @sk - socket to insert into the tables
1073  * @sat - address to search for
1074  *
1075  * Pick a source port when one is not given. If we can find a suitable free
1076  * one, we insert the socket into the tables using it.
1077  *
1078  * This whole operation must be atomic.
1079  */
1080 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1081 {
1082         int retval;
1083
1084         write_lock_bh(&atalk_sockets_lock);
1085
1086         for (sat->sat_port = ATPORT_RESERVED;
1087              sat->sat_port < ATPORT_LAST;
1088              sat->sat_port++) {
1089                 struct sock *s;
1090                 struct hlist_node *node;
1091
1092                 sk_for_each(s, node, &atalk_sockets) {
1093                         struct atalk_sock *at = at_sk(s);
1094
1095                         if (at->src_net == sat->sat_addr.s_net &&
1096                             at->src_node == sat->sat_addr.s_node &&
1097                             at->src_port == sat->sat_port)
1098                                 goto try_next_port;
1099                 }
1100
1101                 /* Wheee, it's free, assign and insert. */
1102                 __atalk_insert_socket(sk);
1103                 at_sk(sk)->src_port = sat->sat_port;
1104                 retval = 0;
1105                 goto out;
1106
1107 try_next_port:;
1108         }
1109
1110         retval = -EBUSY;
1111 out:
1112         write_unlock_bh(&atalk_sockets_lock);
1113         return retval;
1114 }
1115
1116 static int atalk_autobind(struct sock *sk)
1117 {
1118         struct atalk_sock *at = at_sk(sk);
1119         struct sockaddr_at sat;
1120         struct atalk_addr *ap = atalk_find_primary();
1121         int n = -EADDRNOTAVAIL;
1122
1123         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1124                 goto out;
1125
1126         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1127         at->src_node = sat.sat_addr.s_node = ap->s_node;
1128
1129         n = atalk_pick_and_bind_port(sk, &sat);
1130         if (!n)
1131                 sock_reset_flag(sk, SOCK_ZAPPED);
1132 out:
1133         return n;
1134 }
1135
1136 /* Set the address 'our end' of the connection */
1137 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1138 {
1139         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1140         struct sock *sk = sock->sk;
1141         struct atalk_sock *at = at_sk(sk);
1142
1143         if (!sock_flag(sk, SOCK_ZAPPED) ||
1144             addr_len != sizeof(struct sockaddr_at))
1145                 return -EINVAL;
1146
1147         if (addr->sat_family != AF_APPLETALK)
1148                 return -EAFNOSUPPORT;
1149
1150         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1151                 struct atalk_addr *ap = atalk_find_primary();
1152
1153                 if (!ap)
1154                         return -EADDRNOTAVAIL;
1155
1156                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1157                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1158         } else {
1159                 if (!atalk_find_interface(addr->sat_addr.s_net,
1160                                           addr->sat_addr.s_node))
1161                         return -EADDRNOTAVAIL;
1162
1163                 at->src_net  = addr->sat_addr.s_net;
1164                 at->src_node = addr->sat_addr.s_node;
1165         }
1166
1167         if (addr->sat_port == ATADDR_ANYPORT) {
1168                 int n = atalk_pick_and_bind_port(sk, addr);
1169
1170                 if (n < 0)
1171                         return n;
1172         } else {
1173                 at->src_port = addr->sat_port;
1174
1175                 if (atalk_find_or_insert_socket(sk, addr))
1176                         return -EADDRINUSE;
1177         }
1178
1179         sock_reset_flag(sk, SOCK_ZAPPED);
1180         return 0;
1181 }
1182
1183 /* Set the address we talk to */
1184 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1185                          int addr_len, int flags)
1186 {
1187         struct sock *sk = sock->sk;
1188         struct atalk_sock *at = at_sk(sk);
1189         struct sockaddr_at *addr;
1190
1191         sk->sk_state   = TCP_CLOSE;
1192         sock->state = SS_UNCONNECTED;
1193
1194         if (addr_len != sizeof(*addr))
1195                 return -EINVAL;
1196
1197         addr = (struct sockaddr_at *)uaddr;
1198
1199         if (addr->sat_family != AF_APPLETALK)
1200                 return -EAFNOSUPPORT;
1201
1202         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1203             !sock_flag(sk, SOCK_BROADCAST)) {
1204 #if 1
1205                 printk(KERN_WARNING "%s is broken and did not set "
1206                                     "SO_BROADCAST. It will break when 2.2 is "
1207                                     "released.\n",
1208                         current->comm);
1209 #else
1210                 return -EACCES;
1211 #endif
1212         }
1213
1214         if (sock_flag(sk, SOCK_ZAPPED))
1215                 if (atalk_autobind(sk) < 0)
1216                         return -EBUSY;
1217
1218         if (!atrtr_get_dev(&addr->sat_addr))
1219                 return -ENETUNREACH;
1220
1221         at->dest_port = addr->sat_port;
1222         at->dest_net  = addr->sat_addr.s_net;
1223         at->dest_node = addr->sat_addr.s_node;
1224
1225         sock->state  = SS_CONNECTED;
1226         sk->sk_state = TCP_ESTABLISHED;
1227         return 0;
1228 }
1229
1230 /*
1231  * Find the name of an AppleTalk socket. Just copy the right
1232  * fields into the sockaddr.
1233  */
1234 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1235                          int *uaddr_len, int peer)
1236 {
1237         struct sockaddr_at sat;
1238         struct sock *sk = sock->sk;
1239         struct atalk_sock *at = at_sk(sk);
1240
1241         if (sock_flag(sk, SOCK_ZAPPED))
1242                 if (atalk_autobind(sk) < 0)
1243                         return -ENOBUFS;
1244
1245         *uaddr_len = sizeof(struct sockaddr_at);
1246
1247         if (peer) {
1248                 if (sk->sk_state != TCP_ESTABLISHED)
1249                         return -ENOTCONN;
1250
1251                 sat.sat_addr.s_net  = at->dest_net;
1252                 sat.sat_addr.s_node = at->dest_node;
1253                 sat.sat_port        = at->dest_port;
1254         } else {
1255                 sat.sat_addr.s_net  = at->src_net;
1256                 sat.sat_addr.s_node = at->src_node;
1257                 sat.sat_port        = at->src_port;
1258         }
1259
1260         sat.sat_family = AF_APPLETALK;
1261         memcpy(uaddr, &sat, sizeof(sat));
1262         return 0;
1263 }
1264
1265 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1266 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1267 {
1268         return skb->data[12] == 22;
1269 }
1270
1271 static int handle_ip_over_ddp(struct sk_buff *skb)
1272 {
1273         struct net_device *dev = __dev_get_by_name("ipddp0");
1274         struct net_device_stats *stats;
1275
1276         /* This needs to be able to handle ipddp"N" devices */
1277         if (!dev)
1278                 return -ENODEV;
1279
1280         skb->protocol = htons(ETH_P_IP);
1281         skb_pull(skb, 13);
1282         skb->dev   = dev;
1283         skb_reset_transport_header(skb);
1284
1285         stats = dev->priv;
1286         stats->rx_packets++;
1287         stats->rx_bytes += skb->len + 13;
1288         netif_rx(skb);  /* Send the SKB up to a higher place. */
1289         return 0;
1290 }
1291 #else
1292 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1293 #define is_ip_over_ddp(skb) 0
1294 #define handle_ip_over_ddp(skb) 0
1295 #endif
1296
1297 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1298                                struct ddpehdr *ddp, __u16 len_hops,
1299                                int origlen)
1300 {
1301         struct atalk_route *rt;
1302         struct atalk_addr ta;
1303
1304         /*
1305          * Don't route multicast, etc., packets, or packets sent to "this
1306          * network"
1307          */
1308         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1309                 /*
1310                  * FIXME:
1311                  *
1312                  * Can it ever happen that a packet is from a PPP iface and
1313                  * needs to be broadcast onto the default network?
1314                  */
1315                 if (dev->type == ARPHRD_PPP)
1316                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1317                                           "packet received from PPP iface\n");
1318                 goto free_it;
1319         }
1320
1321         ta.s_net  = ddp->deh_dnet;
1322         ta.s_node = ddp->deh_dnode;
1323
1324         /* Route the packet */
1325         rt = atrtr_find(&ta);
1326         /* increment hops count */
1327         len_hops += 1 << 10;
1328         if (!rt || !(len_hops & (15 << 10)))
1329                 goto free_it;
1330
1331         /* FIXME: use skb->cb to be able to use shared skbs */
1332
1333         /*
1334          * Route goes through another gateway, so set the target to the
1335          * gateway instead.
1336          */
1337
1338         if (rt->flags & RTF_GATEWAY) {
1339                 ta.s_net  = rt->gateway.s_net;
1340                 ta.s_node = rt->gateway.s_node;
1341         }
1342
1343         /* Fix up skb->len field */
1344         skb_trim(skb, min_t(unsigned int, origlen,
1345                             (rt->dev->hard_header_len +
1346                              ddp_dl->header_length + (len_hops & 1023))));
1347
1348         /* FIXME: use skb->cb to be able to use shared skbs */
1349         ddp->deh_len_hops = htons(len_hops);
1350
1351         /*
1352          * Send the buffer onwards
1353          *
1354          * Now we must always be careful. If it's come from LocalTalk to
1355          * EtherTalk it might not fit
1356          *
1357          * Order matters here: If a packet has to be copied to make a new
1358          * headroom (rare hopefully) then it won't need unsharing.
1359          *
1360          * Note. ddp-> becomes invalid at the realloc.
1361          */
1362         if (skb_headroom(skb) < 22) {
1363                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1364                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1365                 kfree_skb(skb);
1366                 if (!nskb)
1367                         goto out;
1368                 skb = nskb;
1369         } else
1370                 skb = skb_unshare(skb, GFP_ATOMIC);
1371
1372         /*
1373          * If the buffer didn't vanish into the lack of space bitbucket we can
1374          * send it.
1375          */
1376         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1377                 goto free_it;
1378 out:
1379         return;
1380 free_it:
1381         kfree_skb(skb);
1382 }
1383
1384 /**
1385  *      atalk_rcv - Receive a packet (in skb) from device dev
1386  *      @skb - packet received
1387  *      @dev - network device where the packet comes from
1388  *      @pt - packet type
1389  *
1390  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1391  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1392  *      is the DDP header, skb->len is the DDP length. The physical headers
1393  *      have been extracted. PPP should probably pass frames marked as for this
1394  *      layer.  [ie ARPHRD_ETHERTALK]
1395  */
1396 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1397                      struct packet_type *pt, struct net_device *orig_dev)
1398 {
1399         struct ddpehdr *ddp;
1400         struct sock *sock;
1401         struct atalk_iface *atif;
1402         struct sockaddr_at tosat;
1403         int origlen;
1404         __u16 len_hops;
1405
1406         /* Don't mangle buffer if shared */
1407         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1408                 goto out;
1409
1410         /* Size check and make sure header is contiguous */
1411         if (!pskb_may_pull(skb, sizeof(*ddp)))
1412                 goto freeit;
1413
1414         ddp = ddp_hdr(skb);
1415
1416         len_hops = ntohs(ddp->deh_len_hops);
1417
1418         /* Trim buffer in case of stray trailing data */
1419         origlen = skb->len;
1420         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1421
1422         /*
1423          * Size check to see if ddp->deh_len was crap
1424          * (Otherwise we'll detonate most spectacularly
1425          * in the middle of atalk_checksum() or recvmsg()).
1426          */
1427         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1428                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1429                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1430                 goto freeit;
1431         }
1432
1433         /*
1434          * Any checksums. Note we don't do htons() on this == is assumed to be
1435          * valid for net byte orders all over the networking code...
1436          */
1437         if (ddp->deh_sum &&
1438             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1439                 /* Not a valid AppleTalk frame - dustbin time */
1440                 goto freeit;
1441
1442         /* Check the packet is aimed at us */
1443         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1444                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1445         else
1446                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1447
1448         if (!atif) {
1449                 /* Not ours, so we route the packet via the correct
1450                  * AppleTalk iface
1451                  */
1452                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1453                 goto out;
1454         }
1455
1456         /* if IP over DDP is not selected this code will be optimized out */
1457         if (is_ip_over_ddp(skb))
1458                 return handle_ip_over_ddp(skb);
1459         /*
1460          * Which socket - atalk_search_socket() looks for a *full match*
1461          * of the <net, node, port> tuple.
1462          */
1463         tosat.sat_addr.s_net  = ddp->deh_dnet;
1464         tosat.sat_addr.s_node = ddp->deh_dnode;
1465         tosat.sat_port        = ddp->deh_dport;
1466
1467         sock = atalk_search_socket(&tosat, atif);
1468         if (!sock) /* But not one of our sockets */
1469                 goto freeit;
1470
1471         /* Queue packet (standard) */
1472         skb->sk = sock;
1473
1474         if (sock_queue_rcv_skb(sock, skb) < 0)
1475                 goto freeit;
1476 out:
1477         return 0;
1478 freeit:
1479         kfree_skb(skb);
1480         goto out;
1481 }
1482
1483 /*
1484  * Receive a LocalTalk frame. We make some demands on the caller here.
1485  * Caller must provide enough headroom on the packet to pull the short
1486  * header and append a long one.
1487  */
1488 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1489                      struct packet_type *pt, struct net_device *orig_dev)
1490 {
1491         /* Expand any short form frames */
1492         if (skb_mac_header(skb)[2] == 1) {
1493                 struct ddpehdr *ddp;
1494                 /* Find our address */
1495                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1496
1497                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1498                         goto freeit;
1499
1500                 /* Don't mangle buffer if shared */
1501                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1502                         return 0;
1503
1504                 /*
1505                  * The push leaves us with a ddephdr not an shdr, and
1506                  * handily the port bytes in the right place preset.
1507                  */
1508                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1509
1510                 /* Now fill in the long header */
1511
1512                 /*
1513                  * These two first. The mac overlays the new source/dest
1514                  * network information so we MUST copy these before
1515                  * we write the network numbers !
1516                  */
1517
1518                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1519                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1520
1521                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1522                 ddp->deh_snet  = ap->s_net;
1523                 ddp->deh_sum   = 0;             /* No checksum */
1524                 /*
1525                  * Not sure about this bit...
1526                  */
1527                 /* Non routable, so force a drop if we slip up later */
1528                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1529         }
1530         skb_reset_transport_header(skb);
1531
1532         return atalk_rcv(skb, dev, pt, orig_dev);
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 (sock_flag(sk, SOCK_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         } else {
1597                 struct atalk_addr at_hint;
1598
1599                 at_hint.s_node = 0;
1600                 at_hint.s_net  = at->src_net;
1601
1602                 rt = atrtr_find(&at_hint);
1603         }
1604         if (!rt)
1605                 return -ENETUNREACH;
1606
1607         dev = rt->dev;
1608
1609         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1610                         sk, size, dev->name);
1611
1612         size += dev->hard_header_len;
1613         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1614         if (!skb)
1615                 return err;
1616
1617         skb->sk = sk;
1618         skb_reserve(skb, ddp_dl->header_length);
1619         skb_reserve(skb, dev->hard_header_len);
1620         skb->dev = dev;
1621
1622         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1623
1624         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1625         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1626         ddp->deh_dnet  = usat->sat_addr.s_net;
1627         ddp->deh_snet  = at->src_net;
1628         ddp->deh_dnode = usat->sat_addr.s_node;
1629         ddp->deh_snode = at->src_node;
1630         ddp->deh_dport = usat->sat_port;
1631         ddp->deh_sport = at->src_port;
1632
1633         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1634
1635         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1636         if (err) {
1637                 kfree_skb(skb);
1638                 return -EFAULT;
1639         }
1640
1641         if (sk->sk_no_check == 1)
1642                 ddp->deh_sum = 0;
1643         else
1644                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1645
1646         /*
1647          * Loopback broadcast packets to non gateway targets (ie routes
1648          * to group we are in)
1649          */
1650         if (ddp->deh_dnode == ATADDR_BCAST &&
1651             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1652                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1653
1654                 if (skb2) {
1655                         loopback = 1;
1656                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1657                         if (aarp_send_ddp(dev, skb2,
1658                                           &usat->sat_addr, NULL) == -1)
1659                                 kfree_skb(skb2);
1660                                 /* else queued/sent above in the aarp queue */
1661                 }
1662         }
1663
1664         if (dev->flags & IFF_LOOPBACK || loopback) {
1665                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1666                 /* loop back */
1667                 skb_orphan(skb);
1668                 if (ddp->deh_dnode == ATADDR_BCAST) {
1669                         struct atalk_addr at_lo;
1670
1671                         at_lo.s_node = 0;
1672                         at_lo.s_net  = 0;
1673
1674                         rt = atrtr_find(&at_lo);
1675                         if (!rt) {
1676                                 kfree_skb(skb);
1677                                 return -ENETUNREACH;
1678                         }
1679                         dev = rt->dev;
1680                         skb->dev = dev;
1681                 }
1682                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1683         } else {
1684                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1685                 if (rt->flags & RTF_GATEWAY) {
1686                     gsat.sat_addr = rt->gateway;
1687                     usat = &gsat;
1688                 }
1689
1690                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1691                         kfree_skb(skb);
1692                 /* else queued/sent above in the aarp queue */
1693         }
1694         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1695
1696         return len;
1697 }
1698
1699 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1700                          size_t size, int flags)
1701 {
1702         struct sock *sk = sock->sk;
1703         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1704         struct ddpehdr *ddp;
1705         int copied = 0;
1706         int offset = 0;
1707         int err = 0;
1708         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1709                                                 flags & MSG_DONTWAIT, &err);
1710         if (!skb)
1711                 return err;
1712
1713         /* FIXME: use skb->cb to be able to use shared skbs */
1714         ddp = ddp_hdr(skb);
1715         copied = ntohs(ddp->deh_len_hops) & 1023;
1716
1717         if (sk->sk_type != SOCK_RAW) {
1718                 offset = sizeof(*ddp);
1719                 copied -= offset;
1720         }
1721
1722         if (copied > size) {
1723                 copied = size;
1724                 msg->msg_flags |= MSG_TRUNC;
1725         }
1726         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1727
1728         if (!err) {
1729                 if (sat) {
1730                         sat->sat_family      = AF_APPLETALK;
1731                         sat->sat_port        = ddp->deh_sport;
1732                         sat->sat_addr.s_node = ddp->deh_snode;
1733                         sat->sat_addr.s_net  = ddp->deh_snet;
1734                 }
1735                 msg->msg_namelen = sizeof(*sat);
1736         }
1737
1738         skb_free_datagram(sk, skb);     /* Free the datagram. */
1739         return err ? : copied;
1740 }
1741
1742
1743 /*
1744  * AppleTalk ioctl calls.
1745  */
1746 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1747 {
1748         int rc = -ENOIOCTLCMD;
1749         struct sock *sk = sock->sk;
1750         void __user *argp = (void __user *)arg;
1751
1752         switch (cmd) {
1753                 /* Protocol layer */
1754                 case TIOCOUTQ: {
1755                         long amount = sk->sk_sndbuf -
1756                                       atomic_read(&sk->sk_wmem_alloc);
1757
1758                         if (amount < 0)
1759                                 amount = 0;
1760                         rc = put_user(amount, (int __user *)argp);
1761                         break;
1762                 }
1763                 case TIOCINQ: {
1764                         /*
1765                          * These two are safe on a single CPU system as only
1766                          * user tasks fiddle here
1767                          */
1768                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1769                         long amount = 0;
1770
1771                         if (skb)
1772                                 amount = skb->len - sizeof(struct ddpehdr);
1773                         rc = put_user(amount, (int __user *)argp);
1774                         break;
1775                 }
1776                 case SIOCGSTAMP:
1777                         rc = sock_get_timestamp(sk, argp);
1778                         break;
1779                 case SIOCGSTAMPNS:
1780                         rc = sock_get_timestampns(sk, argp);
1781                         break;
1782                 /* Routing */
1783                 case SIOCADDRT:
1784                 case SIOCDELRT:
1785                         rc = -EPERM;
1786                         if (capable(CAP_NET_ADMIN))
1787                                 rc = atrtr_ioctl(cmd, argp);
1788                         break;
1789                 /* Interface */
1790                 case SIOCGIFADDR:
1791                 case SIOCSIFADDR:
1792                 case SIOCGIFBRDADDR:
1793                 case SIOCATALKDIFADDR:
1794                 case SIOCDIFADDR:
1795                 case SIOCSARP:          /* proxy AARP */
1796                 case SIOCDARP:          /* proxy AARP */
1797                         rtnl_lock();
1798                         rc = atif_ioctl(cmd, argp);
1799                         rtnl_unlock();
1800                         break;
1801         }
1802
1803         return rc;
1804 }
1805
1806
1807 #ifdef CONFIG_COMPAT
1808 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1809 {
1810         /*
1811          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1812          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1813          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1814          * here so there is no generic SIOCPROTOPRIVATE translation in the
1815          * system.
1816          */
1817         return -ENOIOCTLCMD;
1818 }
1819 #endif
1820
1821
1822 static struct net_proto_family atalk_family_ops = {
1823         .family         = PF_APPLETALK,
1824         .create         = atalk_create,
1825         .owner          = THIS_MODULE,
1826 };
1827
1828 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1829         .family         = PF_APPLETALK,
1830         .owner          = THIS_MODULE,
1831         .release        = atalk_release,
1832         .bind           = atalk_bind,
1833         .connect        = atalk_connect,
1834         .socketpair     = sock_no_socketpair,
1835         .accept         = sock_no_accept,
1836         .getname        = atalk_getname,
1837         .poll           = datagram_poll,
1838         .ioctl          = atalk_ioctl,
1839 #ifdef CONFIG_COMPAT
1840         .compat_ioctl   = atalk_compat_ioctl,
1841 #endif
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 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1853
1854 static struct notifier_block ddp_notifier = {
1855         .notifier_call  = ddp_device_event,
1856 };
1857
1858 static struct packet_type ltalk_packet_type = {
1859         .type           = __constant_htons(ETH_P_LOCALTALK),
1860         .func           = ltalk_rcv,
1861 };
1862
1863 static struct packet_type ppptalk_packet_type = {
1864         .type           = __constant_htons(ETH_P_PPPTALK),
1865         .func           = atalk_rcv,
1866 };
1867
1868 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1869
1870 /* Export symbols for use by drivers when AppleTalk is a module */
1871 EXPORT_SYMBOL(aarp_send_ddp);
1872 EXPORT_SYMBOL(atrtr_get_dev);
1873 EXPORT_SYMBOL(atalk_find_dev_addr);
1874
1875 static char atalk_err_snap[] __initdata =
1876         KERN_CRIT "Unable to register DDP with SNAP.\n";
1877
1878 /* Called by proto.c on kernel start up */
1879 static int __init atalk_init(void)
1880 {
1881         int rc = proto_register(&ddp_proto, 0);
1882
1883         if (rc != 0)
1884                 goto out;
1885
1886         (void)sock_register(&atalk_family_ops);
1887         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1888         if (!ddp_dl)
1889                 printk(atalk_err_snap);
1890
1891         dev_add_pack(&ltalk_packet_type);
1892         dev_add_pack(&ppptalk_packet_type);
1893
1894         register_netdevice_notifier(&ddp_notifier);
1895         aarp_proto_init();
1896         atalk_proc_init();
1897         atalk_register_sysctl();
1898 out:
1899         return rc;
1900 }
1901 module_init(atalk_init);
1902
1903 /*
1904  * No explicit module reference count manipulation is needed in the
1905  * protocol. Socket layer sets module reference count for us
1906  * and interfaces reference counting is done
1907  * by the network device layer.
1908  *
1909  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1910  * sockets be closed from user space.
1911  */
1912 static void __exit atalk_exit(void)
1913 {
1914 #ifdef CONFIG_SYSCTL
1915         atalk_unregister_sysctl();
1916 #endif /* CONFIG_SYSCTL */
1917         atalk_proc_exit();
1918         aarp_cleanup_module();  /* General aarp clean-up. */
1919         unregister_netdevice_notifier(&ddp_notifier);
1920         dev_remove_pack(&ltalk_packet_type);
1921         dev_remove_pack(&ppptalk_packet_type);
1922         unregister_snap_client(ddp_dl);
1923         sock_unregister(PF_APPLETALK);
1924         proto_unregister(&ddp_proto);
1925 }
1926 module_exit(atalk_exit);
1927
1928 MODULE_LICENSE("GPL");
1929 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1930 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1931 MODULE_ALIAS_NETPROTO(PF_APPLETALK);