net/appletalk/ddp.c

   1 /*
   2  *      DDP:    An implementation of the AppleTalk DDP protocol for
   3  *              Ethernet 'ELAP'.
   4  *
   5  *              Alan Cox  <alan@lxorguk.ukuu.org.uk>
   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 <linux/compat.h>
  59 #include <linux/slab.h>
  60 #include <net/datalink.h>
  61 #include <net/psnap.h>
  62 #include <net/sock.h>
  63 #include <net/tcp_states.h>
  64 #include <net/route.h>
  65 #include <linux/atalk.h>
  66 #include "../core/kmap_skb.h"
  67
  68 struct datalink_proto *ddp_dl, *aarp_dl;
  69 static const struct proto_ops atalk_dgram_ops;
  70
  71 /**************************************************************************\
  72 *                                                                          *
  73 * Handlers for the socket list.                                            *
  74 *                                                                          *
  75 \**************************************************************************/
  76
  77 HLIST_HEAD(atalk_sockets);
  78 DEFINE_RWLOCK(atalk_sockets_lock);
  79
  80 static inline void __atalk_insert_socket(struct sock *sk)
  81 {
  82         sk_add_node(sk, &atalk_sockets);
  83 }
  84
  85 static inline void atalk_remove_socket(struct sock *sk)
  86 {
  87         write_lock_bh(&atalk_sockets_lock);
  88         sk_del_node_init(sk);
  89         write_unlock_bh(&atalk_sockets_lock);
  90 }
  91
  92 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  93                                         struct atalk_iface *atif)
  94 {
  95         struct sock *s;
  96         struct hlist_node *node;
  97
  98         read_lock_bh(&atalk_sockets_lock);
  99         sk_for_each(s, node, &atalk_sockets) {
 100                 struct atalk_sock *at = at_sk(s);
 101
 102                 if (to->sat_port != at->src_port)
 103                         continue;
 104
 105                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 106                     to->sat_addr.s_node == ATADDR_BCAST)
 107                         goto found;
 108
 109                 if (to->sat_addr.s_net == at->src_net &&
 110                     (to->sat_addr.s_node == at->src_node ||
 111                      to->sat_addr.s_node == ATADDR_BCAST ||
 112                      to->sat_addr.s_node == ATADDR_ANYNODE))
 113                         goto found;
 114
 115                 /* XXXX.0 -- we got a request for this router. make sure
 116                  * that the node is appropriately set. */
 117                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 118                     to->sat_addr.s_net != ATADDR_ANYNET &&
 119                     atif->address.s_node == at->src_node) {
 120                         to->sat_addr.s_node = atif->address.s_node;
 121                         goto found;
 122                 }
 123         }
 124         s = NULL;
 125 found:
 126         read_unlock_bh(&atalk_sockets_lock);
 127         return s;
 128 }
 129
 130 /**
 131  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 132  * @sk - socket to insert in the list if it is not there already
 133  * @sat - address to search for
 134  *
 135  * Try to find a socket matching ADDR in the socket list, if found then return
 136  * it. If not, insert SK into the socket list.
 137  *
 138  * This entire operation must execute atomically.
 139  */
 140 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 141                                                 struct sockaddr_at *sat)
 142 {
 143         struct sock *s;
 144         struct hlist_node *node;
 145         struct atalk_sock *at;
 146
 147         write_lock_bh(&atalk_sockets_lock);
 148         sk_for_each(s, node, &atalk_sockets) {
 149                 at = at_sk(s);
 150
 151                 if (at->src_net == sat->sat_addr.s_net &&
 152                     at->src_node == sat->sat_addr.s_node &&
 153                     at->src_port == sat->sat_port)
 154                         goto found;
 155         }
 156         s = NULL;
 157         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 158 found:
 159         write_unlock_bh(&atalk_sockets_lock);
 160         return s;
 161 }
 162
 163 static void atalk_destroy_timer(unsigned long data)
 164 {
 165         struct sock *sk = (struct sock *)data;
 166
 167         if (sk_has_allocations(sk)) {
 168                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 169                 add_timer(&sk->sk_timer);
 170         } else
 171                 sock_put(sk);
 172 }
 173
 174 static inline void atalk_destroy_socket(struct sock *sk)
 175 {
 176         atalk_remove_socket(sk);
 177         skb_queue_purge(&sk->sk_receive_queue);
 178
 179         if (sk_has_allocations(sk)) {
 180                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
 181                                 (unsigned long)sk);
 182                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 183                 add_timer(&sk->sk_timer);
 184         } else
 185                 sock_put(sk);
 186 }
 187
 188 /**************************************************************************\
 189 *                                                                          *
 190 * Routing tables for the AppleTalk socket layer.                           *
 191 *                                                                          *
 192 \**************************************************************************/
 193
 194 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 195 struct atalk_route *atalk_routes;
 196 DEFINE_RWLOCK(atalk_routes_lock);
 197
 198 struct atalk_iface *atalk_interfaces;
 199 DEFINE_RWLOCK(atalk_interfaces_lock);
 200
 201 /* For probing devices or in a routerless network */
 202 struct atalk_route atrtr_default;
 203
 204 /* AppleTalk interface control */
 205 /*
 206  * Drop a device. Doesn't drop any of its routes - that is the caller's
 207  * problem. Called when we down the interface or delete the address.
 208  */
 209 static void atif_drop_device(struct net_device *dev)
 210 {
 211         struct atalk_iface **iface = &atalk_interfaces;
 212         struct atalk_iface *tmp;
 213
 214         write_lock_bh(&atalk_interfaces_lock);
 215         while ((tmp = *iface) != NULL) {
 216                 if (tmp->dev == dev) {
 217                         *iface = tmp->next;
 218                         dev_put(dev);
 219                         kfree(tmp);
 220                         dev->atalk_ptr = NULL;
 221                 } else
 222                         iface = &tmp->next;
 223         }
 224         write_unlock_bh(&atalk_interfaces_lock);
 225 }
 226
 227 static struct atalk_iface *atif_add_device(struct net_device *dev,
 228                                            struct atalk_addr *sa)
 229 {
 230         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 231
 232         if (!iface)
 233                 goto out;
 234
 235         dev_hold(dev);
 236         iface->dev = dev;
 237         dev->atalk_ptr = iface;
 238         iface->address = *sa;
 239         iface->status = 0;
 240
 241         write_lock_bh(&atalk_interfaces_lock);
 242         iface->next = atalk_interfaces;
 243         atalk_interfaces = iface;
 244         write_unlock_bh(&atalk_interfaces_lock);
 245 out:
 246         return iface;
 247 }
 248
 249 /* Perform phase 2 AARP probing on our tentative address */
 250 static int atif_probe_device(struct atalk_iface *atif)
 251 {
 252         int netrange = ntohs(atif->nets.nr_lastnet) -
 253                         ntohs(atif->nets.nr_firstnet) + 1;
 254         int probe_net = ntohs(atif->address.s_net);
 255         int probe_node = atif->address.s_node;
 256         int netct, nodect;
 257
 258         /* Offset the network we start probing with */
 259         if (probe_net == ATADDR_ANYNET) {
 260                 probe_net = ntohs(atif->nets.nr_firstnet);
 261                 if (netrange)
 262                         probe_net += jiffies % netrange;
 263         }
 264         if (probe_node == ATADDR_ANYNODE)
 265                 probe_node = jiffies & 0xFF;
 266
 267         /* Scan the networks */
 268         atif->status |= ATIF_PROBE;
 269         for (netct = 0; netct <= netrange; netct++) {
 270                 /* Sweep the available nodes from a given start */
 271                 atif->address.s_net = htons(probe_net);
 272                 for (nodect = 0; nodect < 256; nodect++) {
 273                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 274                         if (atif->address.s_node > 0 &&
 275                             atif->address.s_node < 254) {
 276                                 /* Probe a proposed address */
 277                                 aarp_probe_network(atif);
 278
 279                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 280                                         atif->status &= ~ATIF_PROBE;
 281                                         return 0;
 282                                 }
 283                         }
 284                         atif->status &= ~ATIF_PROBE_FAIL;
 285                 }
 286                 probe_net++;
 287                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 288                         probe_net = ntohs(atif->nets.nr_firstnet);
 289         }
 290         atif->status &= ~ATIF_PROBE;
 291
 292         return -EADDRINUSE;     /* Network is full... */
 293 }
 294
 295
 296 /* Perform AARP probing for a proxy address */
 297 static int atif_proxy_probe_device(struct atalk_iface *atif,
 298                                    struct atalk_addr* proxy_addr)
 299 {
 300         int netrange = ntohs(atif->nets.nr_lastnet) -
 301                         ntohs(atif->nets.nr_firstnet) + 1;
 302         /* we probe the interface's network */
 303         int probe_net = ntohs(atif->address.s_net);
 304         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 305         int netct, nodect;
 306
 307         /* Offset the network we start probing with */
 308         if (probe_net == ATADDR_ANYNET) {
 309                 probe_net = ntohs(atif->nets.nr_firstnet);
 310                 if (netrange)
 311                         probe_net += jiffies % netrange;
 312         }
 313
 314         if (probe_node == ATADDR_ANYNODE)
 315                 probe_node = jiffies & 0xFF;
 316
 317         /* Scan the networks */
 318         for (netct = 0; netct <= netrange; netct++) {
 319                 /* Sweep the available nodes from a given start */
 320                 proxy_addr->s_net = htons(probe_net);
 321                 for (nodect = 0; nodect < 256; nodect++) {
 322                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 323                         if (proxy_addr->s_node > 0 &&
 324                             proxy_addr->s_node < 254) {
 325                                 /* Tell AARP to probe a proposed address */
 326                                 int ret = aarp_proxy_probe_network(atif,
 327                                                                     proxy_addr);
 328
 329                                 if (ret != -EADDRINUSE)
 330                                         return ret;
 331                         }
 332                 }
 333                 probe_net++;
 334                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 335                         probe_net = ntohs(atif->nets.nr_firstnet);
 336         }
 337
 338         return -EADDRINUSE;     /* Network is full... */
 339 }
 340
 341
 342 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 343 {
 344         struct atalk_iface *iface = dev->atalk_ptr;
 345         return iface ? &iface->address : NULL;
 346 }
 347
 348 static struct atalk_addr *atalk_find_primary(void)
 349 {
 350         struct atalk_iface *fiface = NULL;
 351         struct atalk_addr *retval;
 352         struct atalk_iface *iface;
 353
 354         /*
 355          * Return a point-to-point interface only if
 356          * there is no non-ptp interface available.
 357          */
 358         read_lock_bh(&atalk_interfaces_lock);
 359         for (iface = atalk_interfaces; iface; iface = iface->next) {
 360                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 361                         fiface = iface;
 362                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 363                         retval = &iface->address;
 364                         goto out;
 365                 }
 366         }
 367
 368         if (fiface)
 369                 retval = &fiface->address;
 370         else if (atalk_interfaces)
 371                 retval = &atalk_interfaces->address;
 372         else
 373                 retval = NULL;
 374 out:
 375         read_unlock_bh(&atalk_interfaces_lock);
 376         return retval;
 377 }
 378
 379 /*
 380  * Find a match for 'any network' - ie any of our interfaces with that
 381  * node number will do just nicely.
 382  */
 383 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 384 {
 385         struct atalk_iface *iface = dev->atalk_ptr;
 386
 387         if (!iface || iface->status & ATIF_PROBE)
 388                 goto out_err;
 389
 390         if (node != ATADDR_BCAST &&
 391             iface->address.s_node != node &&
 392             node != ATADDR_ANYNODE)
 393                 goto out_err;
 394 out:
 395         return iface;
 396 out_err:
 397         iface = NULL;
 398         goto out;
 399 }
 400
 401 /* Find a match for a specific network:node pair */
 402 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 403 {
 404         struct atalk_iface *iface;
 405
 406         read_lock_bh(&atalk_interfaces_lock);
 407         for (iface = atalk_interfaces; iface; iface = iface->next) {
 408                 if ((node == ATADDR_BCAST ||
 409                      node == ATADDR_ANYNODE ||
 410                      iface->address.s_node == node) &&
 411                     iface->address.s_net == net &&
 412                     !(iface->status & ATIF_PROBE))
 413                         break;
 414
 415                 /* XXXX.0 -- net.0 returns the iface associated with net */
 416                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 417                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 418                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 419                         break;
 420         }
 421         read_unlock_bh(&atalk_interfaces_lock);
 422         return iface;
 423 }
 424
 425
 426 /*
 427  * Find a route for an AppleTalk packet. This ought to get cached in
 428  * the socket (later on...). We know about host routes and the fact
 429  * that a route must be direct to broadcast.
 430  */
 431 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 432 {
 433         /*
 434          * we must search through all routes unless we find a
 435          * host route, because some host routes might overlap
 436          * network routes
 437          */
 438         struct atalk_route *net_route = NULL;
 439         struct atalk_route *r;
 440
 441         read_lock_bh(&atalk_routes_lock);
 442         for (r = atalk_routes; r; r = r->next) {
 443                 if (!(r->flags & RTF_UP))
 444                         continue;
 445
 446                 if (r->target.s_net == target->s_net) {
 447                         if (r->flags & RTF_HOST) {
 448                                 /*
 449                                  * if this host route is for the target,
 450                                  * the we're done
 451                                  */
 452                                 if (r->target.s_node == target->s_node)
 453                                         goto out;
 454                         } else
 455                                 /*
 456                                  * this route will work if there isn't a
 457                                  * direct host route, so cache it
 458                                  */
 459                                 net_route = r;
 460                 }
 461         }
 462
 463         /*
 464          * if we found a network route but not a direct host
 465          * route, then return it
 466          */
 467         if (net_route)
 468                 r = net_route;
 469         else if (atrtr_default.dev)
 470                 r = &atrtr_default;
 471         else /* No route can be found */
 472                 r = NULL;
 473 out:
 474         read_unlock_bh(&atalk_routes_lock);
 475         return r;
 476 }
 477
 478
 479 /*
 480  * Given an AppleTalk network, find the device to use. This can be
 481  * a simple lookup.
 482  */
 483 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 484 {
 485         struct atalk_route *atr = atrtr_find(sa);
 486         return atr ? atr->dev : NULL;
 487 }
 488
 489 /* Set up a default router */
 490 static void atrtr_set_default(struct net_device *dev)
 491 {
 492         atrtr_default.dev            = dev;
 493         atrtr_default.flags          = RTF_UP;
 494         atrtr_default.gateway.s_net  = htons(0);
 495         atrtr_default.gateway.s_node = 0;
 496 }
 497
 498 /*
 499  * Add a router. Basically make sure it looks valid and stuff the
 500  * entry in the list. While it uses netranges we always set them to one
 501  * entry to work like netatalk.
 502  */
 503 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 504 {
 505         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 506         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 507         struct atalk_route *rt;
 508         struct atalk_iface *iface, *riface;
 509         int retval = -EINVAL;
 510
 511         /*
 512          * Fixme: Raise/Lower a routing change semaphore for these
 513          * operations.
 514          */
 515
 516         /* Validate the request */
 517         if (ta->sat_family != AF_APPLETALK ||
 518             (!devhint && ga->sat_family != AF_APPLETALK))
 519                 goto out;
 520
 521         /* Now walk the routing table and make our decisions */
 522         write_lock_bh(&atalk_routes_lock);
 523         for (rt = atalk_routes; rt; rt = rt->next) {
 524                 if (r->rt_flags != rt->flags)
 525                         continue;
 526
 527                 if (ta->sat_addr.s_net == rt->target.s_net) {
 528                         if (!(rt->flags & RTF_HOST))
 529                                 break;
 530                         if (ta->sat_addr.s_node == rt->target.s_node)
 531                                 break;
 532                 }
 533         }
 534
 535         if (!devhint) {
 536                 riface = NULL;
 537
 538                 read_lock_bh(&atalk_interfaces_lock);
 539                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 540                         if (!riface &&
 541                             ntohs(ga->sat_addr.s_net) >=
 542                                         ntohs(iface->nets.nr_firstnet) &&
 543                             ntohs(ga->sat_addr.s_net) <=
 544                                         ntohs(iface->nets.nr_lastnet))
 545                                 riface = iface;
 546
 547                         if (ga->sat_addr.s_net == iface->address.s_net &&
 548                             ga->sat_addr.s_node == iface->address.s_node)
 549                                 riface = iface;
 550                 }
 551                 read_unlock_bh(&atalk_interfaces_lock);
 552
 553                 retval = -ENETUNREACH;
 554                 if (!riface)
 555                         goto out_unlock;
 556
 557                 devhint = riface->dev;
 558         }
 559
 560         if (!rt) {
 561                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 562
 563                 retval = -ENOBUFS;
 564                 if (!rt)
 565                         goto out_unlock;
 566
 567                 rt->next = atalk_routes;
 568                 atalk_routes = rt;
 569         }
 570
 571         /* Fill in the routing entry */
 572         rt->target  = ta->sat_addr;
 573         dev_hold(devhint);
 574         rt->dev     = devhint;
 575         rt->flags   = r->rt_flags;
 576         rt->gateway = ga->sat_addr;
 577
 578         retval = 0;
 579 out_unlock:
 580         write_unlock_bh(&atalk_routes_lock);
 581 out:
 582         return retval;
 583 }
 584
 585 /* Delete a route. Find it and discard it */
 586 static int atrtr_delete(struct atalk_addr * addr)
 587 {
 588         struct atalk_route **r = &atalk_routes;
 589         int retval = 0;
 590         struct atalk_route *tmp;
 591
 592         write_lock_bh(&atalk_routes_lock);
 593         while ((tmp = *r) != NULL) {
 594                 if (tmp->target.s_net == addr->s_net &&
 595                     (!(tmp->flags&RTF_GATEWAY) ||
 596                      tmp->target.s_node == addr->s_node)) {
 597                         *r = tmp->next;
 598                         dev_put(tmp->dev);
 599                         kfree(tmp);
 600                         goto out;
 601                 }
 602                 r = &tmp->next;
 603         }
 604         retval = -ENOENT;
 605 out:
 606         write_unlock_bh(&atalk_routes_lock);
 607         return retval;
 608 }
 609
 610 /*
 611  * Called when a device is downed. Just throw away any routes
 612  * via it.
 613  */
 614 static void atrtr_device_down(struct net_device *dev)
 615 {
 616         struct atalk_route **r = &atalk_routes;
 617         struct atalk_route *tmp;
 618
 619         write_lock_bh(&atalk_routes_lock);
 620         while ((tmp = *r) != NULL) {
 621                 if (tmp->dev == dev) {
 622                         *r = tmp->next;
 623                         dev_put(dev);
 624                         kfree(tmp);
 625                 } else
 626                         r = &tmp->next;
 627         }
 628         write_unlock_bh(&atalk_routes_lock);
 629
 630         if (atrtr_default.dev == dev)
 631                 atrtr_set_default(NULL);
 632 }
 633
 634 /* Actually down the interface */
 635 static inline void atalk_dev_down(struct net_device *dev)
 636 {
 637         atrtr_device_down(dev); /* Remove all routes for the device */
 638         aarp_device_down(dev);  /* Remove AARP entries for the device */
 639         atif_drop_device(dev);  /* Remove the device */
 640 }
 641
 642 /*
 643  * A device event has occurred. Watch for devices going down and
 644  * delete our use of them (iface and route).
 645  */
 646 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 647                             void *ptr)
 648 {
 649         struct net_device *dev = ptr;
 650
 651         if (!net_eq(dev_net(dev), &init_net))
 652                 return NOTIFY_DONE;
 653
 654         if (event == NETDEV_DOWN)
 655                 /* Discard any use of this */
 656                 atalk_dev_down(dev);
 657
 658         return NOTIFY_DONE;
 659 }
 660
 661 /* ioctl calls. Shouldn't even need touching */
 662 /* Device configuration ioctl calls */
 663 static int atif_ioctl(int cmd, void __user *arg)
 664 {
 665         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 666         struct ifreq atreq;
 667         struct atalk_netrange *nr;
 668         struct sockaddr_at *sa;
 669         struct net_device *dev;
 670         struct atalk_iface *atif;
 671         int ct;
 672         int limit;
 673         struct rtentry rtdef;
 674         int add_route;
 675
 676         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 677                 return -EFAULT;
 678
 679         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
 680         if (!dev)
 681                 return -ENODEV;
 682
 683         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 684         atif = atalk_find_dev(dev);
 685
 686         switch (cmd) {
 687                 case SIOCSIFADDR:
 688                         if (!capable(CAP_NET_ADMIN))
 689                                 return -EPERM;
 690                         if (sa->sat_family != AF_APPLETALK)
 691                                 return -EINVAL;
 692                         if (dev->type != ARPHRD_ETHER &&
 693                             dev->type != ARPHRD_LOOPBACK &&
 694                             dev->type != ARPHRD_LOCALTLK &&
 695                             dev->type != ARPHRD_PPP)
 696                                 return -EPROTONOSUPPORT;
 697
 698                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 699                         add_route = 1;
 700
 701                         /*
 702                          * if this is a point-to-point iface, and we already
 703                          * have an iface for this AppleTalk address, then we
 704                          * should not add a route
 705                          */
 706                         if ((dev->flags & IFF_POINTOPOINT) &&
 707                             atalk_find_interface(sa->sat_addr.s_net,
 708                                                  sa->sat_addr.s_node)) {
 709                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 710                                                   "interface added with "
 711                                                   "existing address\n");
 712                                 add_route = 0;
 713                         }
 714
 715                         /*
 716                          * Phase 1 is fine on LocalTalk but we don't do
 717                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 718                          */
 719                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 720                                 return -EPROTONOSUPPORT;
 721                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 722                             sa->sat_addr.s_node == 254)
 723                                 return -EINVAL;
 724                         if (atif) {
 725                                 /* Already setting address */
 726                                 if (atif->status & ATIF_PROBE)
 727                                         return -EBUSY;
 728
 729                                 atif->address.s_net  = sa->sat_addr.s_net;
 730                                 atif->address.s_node = sa->sat_addr.s_node;
 731                                 atrtr_device_down(dev); /* Flush old routes */
 732                         } else {
 733                                 atif = atif_add_device(dev, &sa->sat_addr);
 734                                 if (!atif)
 735                                         return -ENOMEM;
 736                         }
 737                         atif->nets = *nr;
 738
 739                         /*
 740                          * Check if the chosen address is used. If so we
 741                          * error and atalkd will try another.
 742                          */
 743
 744                         if (!(dev->flags & IFF_LOOPBACK) &&
 745                             !(dev->flags & IFF_POINTOPOINT) &&
 746                             atif_probe_device(atif) < 0) {
 747                                 atif_drop_device(dev);
 748                                 return -EADDRINUSE;
 749                         }
 750
 751                         /* Hey it worked - add the direct routes */
 752                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 753                         sa->sat_family = AF_APPLETALK;
 754                         sa->sat_addr.s_net  = atif->address.s_net;
 755                         sa->sat_addr.s_node = atif->address.s_node;
 756                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 757                         rtdef.rt_flags = RTF_UP;
 758                         sa->sat_family = AF_APPLETALK;
 759                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 760                         if (dev->flags & IFF_LOOPBACK ||
 761                             dev->flags & IFF_POINTOPOINT)
 762                                 rtdef.rt_flags |= RTF_HOST;
 763
 764                         /* Routerless initial state */
 765                         if (nr->nr_firstnet == htons(0) &&
 766                             nr->nr_lastnet == htons(0xFFFE)) {
 767                                 sa->sat_addr.s_net = atif->address.s_net;
 768                                 atrtr_create(&rtdef, dev);
 769                                 atrtr_set_default(dev);
 770                         } else {
 771                                 limit = ntohs(nr->nr_lastnet);
 772                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 773                                         printk(KERN_WARNING "Too many routes/"
 774                                                             "iface.\n");
 775                                         return -EINVAL;
 776                                 }
 777                                 if (add_route)
 778                                         for (ct = ntohs(nr->nr_firstnet);
 779                                              ct <= limit; ct++) {
 780                                                 sa->sat_addr.s_net = htons(ct);
 781                                                 atrtr_create(&rtdef, dev);
 782                                         }
 783                         }
 784                         dev_mc_add_global(dev, aarp_mcast);
 785                         return 0;
 786
 787                 case SIOCGIFADDR:
 788                         if (!atif)
 789                                 return -EADDRNOTAVAIL;
 790
 791                         sa->sat_family = AF_APPLETALK;
 792                         sa->sat_addr = atif->address;
 793                         break;
 794
 795                 case SIOCGIFBRDADDR:
 796                         if (!atif)
 797                                 return -EADDRNOTAVAIL;
 798
 799                         sa->sat_family = AF_APPLETALK;
 800                         sa->sat_addr.s_net = atif->address.s_net;
 801                         sa->sat_addr.s_node = ATADDR_BCAST;
 802                         break;
 803
 804                 case SIOCATALKDIFADDR:
 805                 case SIOCDIFADDR:
 806                         if (!capable(CAP_NET_ADMIN))
 807                                 return -EPERM;
 808                         if (sa->sat_family != AF_APPLETALK)
 809                                 return -EINVAL;
 810                         atalk_dev_down(dev);
 811                         break;
 812
 813                 case SIOCSARP:
 814                         if (!capable(CAP_NET_ADMIN))
 815                                 return -EPERM;
 816                         if (sa->sat_family != AF_APPLETALK)
 817                                 return -EINVAL;
 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(&init_net, 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 = rol16(sum, 1);
 928         }
 929         return sum;
 930 }
 931
 932 /*  Checksum skb data --  similar to skb_checksum  */
 933 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 934                                    int len, unsigned long sum)
 935 {
 936         int start = skb_headlen(skb);
 937         struct sk_buff *frag_iter;
 938         int i, copy;
 939
 940         /* checksum stuff in header space */
 941         if ( (copy = start - offset) > 0) {
 942                 if (copy > len)
 943                         copy = len;
 944                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 945                 if ( (len -= copy) == 0)
 946                         return sum;
 947
 948                 offset += copy;
 949         }
 950
 951         /* checksum stuff in frags */
 952         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 953                 int end;
 954
 955                 WARN_ON(start > offset + len);
 956
 957                 end = start + skb_shinfo(skb)->frags[i].size;
 958                 if ((copy = end - offset) > 0) {
 959                         u8 *vaddr;
 960                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 961
 962                         if (copy > len)
 963                                 copy = len;
 964                         vaddr = kmap_skb_frag(frag);
 965                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 966                                                   offset - start, copy, sum);
 967                         kunmap_skb_frag(vaddr);
 968
 969                         if (!(len -= copy))
 970                                 return sum;
 971                         offset += copy;
 972                 }
 973                 start = end;
 974         }
 975
 976         skb_walk_frags(skb, frag_iter) {
 977                 int end;
 978
 979                 WARN_ON(start > offset + len);
 980
 981                 end = start + frag_iter->len;
 982                 if ((copy = end - offset) > 0) {
 983                         if (copy > len)
 984                                 copy = len;
 985                         sum = atalk_sum_skb(frag_iter, offset - start,
 986                                             copy, sum);
 987                         if ((len -= copy) == 0)
 988                                 return sum;
 989                         offset += copy;
 990                 }
 991                 start = end;
 992         }
 993
 994         BUG_ON(len > 0);
 995
 996         return sum;
 997 }
 998
 999 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1000 {
1001         unsigned long sum;
1002
1003         /* skip header 4 bytes */
1004         sum = atalk_sum_skb(skb, 4, len-4, 0);
1005
1006         /* Use 0xFFFF for 0. 0 itself means none */
1007         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1008 }
1009
1010 static struct proto ddp_proto = {
1011         .name     = "DDP",
1012         .owner    = THIS_MODULE,
1013         .obj_size = sizeof(struct atalk_sock),
1014 };
1015
1016 /*
1017  * Create a socket. Initialise the socket, blank the addresses
1018  * set the state.
1019  */
1020 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1021                         int kern)
1022 {
1023         struct sock *sk;
1024         int rc = -ESOCKTNOSUPPORT;
1025
1026         if (!net_eq(net, &init_net))
1027                 return -EAFNOSUPPORT;
1028
1029         /*
1030          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1031          * and gives you the full ELAP frame. Should be handy for CAP 8)
1032          */
1033         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1034                 goto out;
1035         rc = -ENOMEM;
1036         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1037         if (!sk)
1038                 goto out;
1039         rc = 0;
1040         sock->ops = &atalk_dgram_ops;
1041         sock_init_data(sock, sk);
1042
1043         /* Checksums on by default */
1044         sock_set_flag(sk, SOCK_ZAPPED);
1045 out:
1046         return rc;
1047 }
1048
1049 /* Free a socket. No work needed */
1050 static int atalk_release(struct socket *sock)
1051 {
1052         struct sock *sk = sock->sk;
1053
1054         lock_sock(sk);
1055         if (sk) {
1056                 sock_orphan(sk);
1057                 sock->sk = NULL;
1058                 atalk_destroy_socket(sk);
1059         }
1060         release_sock(sk);
1061         return 0;
1062 }
1063
1064 /**
1065  * atalk_pick_and_bind_port - Pick a source port when one is not given
1066  * @sk - socket to insert into the tables
1067  * @sat - address to search for
1068  *
1069  * Pick a source port when one is not given. If we can find a suitable free
1070  * one, we insert the socket into the tables using it.
1071  *
1072  * This whole operation must be atomic.
1073  */
1074 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1075 {
1076         int retval;
1077
1078         write_lock_bh(&atalk_sockets_lock);
1079
1080         for (sat->sat_port = ATPORT_RESERVED;
1081              sat->sat_port < ATPORT_LAST;
1082              sat->sat_port++) {
1083                 struct sock *s;
1084                 struct hlist_node *node;
1085
1086                 sk_for_each(s, node, &atalk_sockets) {
1087                         struct atalk_sock *at = at_sk(s);
1088
1089                         if (at->src_net == sat->sat_addr.s_net &&
1090                             at->src_node == sat->sat_addr.s_node &&
1091                             at->src_port == sat->sat_port)
1092                                 goto try_next_port;
1093                 }
1094
1095                 /* Wheee, it's free, assign and insert. */
1096                 __atalk_insert_socket(sk);
1097                 at_sk(sk)->src_port = sat->sat_port;
1098                 retval = 0;
1099                 goto out;
1100
1101 try_next_port:;
1102         }
1103
1104         retval = -EBUSY;
1105 out:
1106         write_unlock_bh(&atalk_sockets_lock);
1107         return retval;
1108 }
1109
1110 static int atalk_autobind(struct sock *sk)
1111 {
1112         struct atalk_sock *at = at_sk(sk);
1113         struct sockaddr_at sat;
1114         struct atalk_addr *ap = atalk_find_primary();
1115         int n = -EADDRNOTAVAIL;
1116
1117         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1118                 goto out;
1119
1120         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1121         at->src_node = sat.sat_addr.s_node = ap->s_node;
1122
1123         n = atalk_pick_and_bind_port(sk, &sat);
1124         if (!n)
1125                 sock_reset_flag(sk, SOCK_ZAPPED);
1126 out:
1127         return n;
1128 }
1129
1130 /* Set the address 'our end' of the connection */
1131 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1132 {
1133         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1134         struct sock *sk = sock->sk;
1135         struct atalk_sock *at = at_sk(sk);
1136         int err;
1137
1138         if (!sock_flag(sk, SOCK_ZAPPED) ||
1139             addr_len != sizeof(struct sockaddr_at))
1140                 return -EINVAL;
1141
1142         if (addr->sat_family != AF_APPLETALK)
1143                 return -EAFNOSUPPORT;
1144
1145         lock_sock(sk);
1146         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1147                 struct atalk_addr *ap = atalk_find_primary();
1148
1149                 err = -EADDRNOTAVAIL;
1150                 if (!ap)
1151                         goto out;
1152
1153                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1154                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1155         } else {
1156                 err = -EADDRNOTAVAIL;
1157                 if (!atalk_find_interface(addr->sat_addr.s_net,
1158                                           addr->sat_addr.s_node))
1159                         goto out;
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                 err = atalk_pick_and_bind_port(sk, addr);
1167
1168                 if (err < 0)
1169                         goto out;
1170         } else {
1171                 at->src_port = addr->sat_port;
1172
1173                 err = -EADDRINUSE;
1174                 if (atalk_find_or_insert_socket(sk, addr))
1175                         goto out;
1176         }
1177
1178         sock_reset_flag(sk, SOCK_ZAPPED);
1179         err = 0;
1180 out:
1181         release_sock(sk);
1182         return err;
1183 }
1184
1185 /* Set the address we talk to */
1186 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1187                          int addr_len, int flags)
1188 {
1189         struct sock *sk = sock->sk;
1190         struct atalk_sock *at = at_sk(sk);
1191         struct sockaddr_at *addr;
1192         int err;
1193
1194         sk->sk_state   = TCP_CLOSE;
1195         sock->state = SS_UNCONNECTED;
1196
1197         if (addr_len != sizeof(*addr))
1198                 return -EINVAL;
1199
1200         addr = (struct sockaddr_at *)uaddr;
1201
1202         if (addr->sat_family != AF_APPLETALK)
1203                 return -EAFNOSUPPORT;
1204
1205         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1206             !sock_flag(sk, SOCK_BROADCAST)) {
1207 #if 1
1208                 printk(KERN_WARNING "%s is broken and did not set "
1209                                     "SO_BROADCAST. It will break when 2.2 is "
1210                                     "released.\n",
1211                         current->comm);
1212 #else
1213                 return -EACCES;
1214 #endif
1215         }
1216
1217         lock_sock(sk);
1218         err = -EBUSY;
1219         if (sock_flag(sk, SOCK_ZAPPED))
1220                 if (atalk_autobind(sk) < 0)
1221                         goto out;
1222
1223         err = -ENETUNREACH;
1224         if (!atrtr_get_dev(&addr->sat_addr))
1225                 goto out;
1226
1227         at->dest_port = addr->sat_port;
1228         at->dest_net  = addr->sat_addr.s_net;
1229         at->dest_node = addr->sat_addr.s_node;
1230
1231         sock->state  = SS_CONNECTED;
1232         sk->sk_state = TCP_ESTABLISHED;
1233         err = 0;
1234 out:
1235         release_sock(sk);
1236         return err;
1237 }
1238
1239 /*
1240  * Find the name of an AppleTalk socket. Just copy the right
1241  * fields into the sockaddr.
1242  */
1243 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1244                          int *uaddr_len, int peer)
1245 {
1246         struct sockaddr_at sat;
1247         struct sock *sk = sock->sk;
1248         struct atalk_sock *at = at_sk(sk);
1249         int err;
1250
1251         lock_sock(sk);
1252         err = -ENOBUFS;
1253         if (sock_flag(sk, SOCK_ZAPPED))
1254                 if (atalk_autobind(sk) < 0)
1255                         goto out;
1256
1257         *uaddr_len = sizeof(struct sockaddr_at);
1258         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
1259
1260         if (peer) {
1261                 err = -ENOTCONN;
1262                 if (sk->sk_state != TCP_ESTABLISHED)
1263                         goto out;
1264
1265                 sat.sat_addr.s_net  = at->dest_net;
1266                 sat.sat_addr.s_node = at->dest_node;
1267                 sat.sat_port        = at->dest_port;
1268         } else {
1269                 sat.sat_addr.s_net  = at->src_net;
1270                 sat.sat_addr.s_node = at->src_node;
1271                 sat.sat_port        = at->src_port;
1272         }
1273
1274         err = 0;
1275         sat.sat_family = AF_APPLETALK;
1276         memcpy(uaddr, &sat, sizeof(sat));
1277
1278 out:
1279         release_sock(sk);
1280         return err;
1281 }
1282
1283 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1284 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1285 {
1286         return skb->data[12] == 22;
1287 }
1288
1289 static int handle_ip_over_ddp(struct sk_buff *skb)
1290 {
1291         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1292         struct net_device_stats *stats;
1293
1294         /* This needs to be able to handle ipddp"N" devices */
1295         if (!dev) {
1296                 kfree_skb(skb);
1297                 return NET_RX_DROP;
1298         }
1299
1300         skb->protocol = htons(ETH_P_IP);
1301         skb_pull(skb, 13);
1302         skb->dev   = dev;
1303         skb_reset_transport_header(skb);
1304
1305         stats = netdev_priv(dev);
1306         stats->rx_packets++;
1307         stats->rx_bytes += skb->len + 13;
1308         return netif_rx(skb);  /* Send the SKB up to a higher place. */
1309 }
1310 #else
1311 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1312 #define is_ip_over_ddp(skb) 0
1313 #define handle_ip_over_ddp(skb) 0
1314 #endif
1315
1316 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1317                               struct ddpehdr *ddp, __u16 len_hops, int origlen)
1318 {
1319         struct atalk_route *rt;
1320         struct atalk_addr ta;
1321
1322         /*
1323          * Don't route multicast, etc., packets, or packets sent to "this
1324          * network"
1325          */
1326         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1327                 /*
1328                  * FIXME:
1329                  *
1330                  * Can it ever happen that a packet is from a PPP iface and
1331                  * needs to be broadcast onto the default network?
1332                  */
1333                 if (dev->type == ARPHRD_PPP)
1334                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1335                                           "packet received from PPP iface\n");
1336                 goto free_it;
1337         }
1338
1339         ta.s_net  = ddp->deh_dnet;
1340         ta.s_node = ddp->deh_dnode;
1341
1342         /* Route the packet */
1343         rt = atrtr_find(&ta);
1344         /* increment hops count */
1345         len_hops += 1 << 10;
1346         if (!rt || !(len_hops & (15 << 10)))
1347                 goto free_it;
1348
1349         /* FIXME: use skb->cb to be able to use shared skbs */
1350
1351         /*
1352          * Route goes through another gateway, so set the target to the
1353          * gateway instead.
1354          */
1355
1356         if (rt->flags & RTF_GATEWAY) {
1357                 ta.s_net  = rt->gateway.s_net;
1358                 ta.s_node = rt->gateway.s_node;
1359         }
1360
1361         /* Fix up skb->len field */
1362         skb_trim(skb, min_t(unsigned int, origlen,
1363                             (rt->dev->hard_header_len +
1364                              ddp_dl->header_length + (len_hops & 1023))));
1365
1366         /* FIXME: use skb->cb to be able to use shared skbs */
1367         ddp->deh_len_hops = htons(len_hops);
1368
1369         /*
1370          * Send the buffer onwards
1371          *
1372          * Now we must always be careful. If it's come from LocalTalk to
1373          * EtherTalk it might not fit
1374          *
1375          * Order matters here: If a packet has to be copied to make a new
1376          * headroom (rare hopefully) then it won't need unsharing.
1377          *
1378          * Note. ddp-> becomes invalid at the realloc.
1379          */
1380         if (skb_headroom(skb) < 22) {
1381                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1382                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1383                 kfree_skb(skb);
1384                 skb = nskb;
1385         } else
1386                 skb = skb_unshare(skb, GFP_ATOMIC);
1387
1388         /*
1389          * If the buffer didn't vanish into the lack of space bitbucket we can
1390          * send it.
1391          */
1392         if (skb == NULL)
1393                 goto drop;
1394
1395         if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1396                 return NET_RX_DROP;
1397         return NET_RX_SUCCESS;
1398 free_it:
1399         kfree_skb(skb);
1400 drop:
1401         return NET_RX_DROP;
1402 }
1403
1404 /**
1405  *      atalk_rcv - Receive a packet (in skb) from device dev
1406  *      @skb - packet received
1407  *      @dev - network device where the packet comes from
1408  *      @pt - packet type
1409  *
1410  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1411  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1412  *      is the DDP header, skb->len is the DDP length. The physical headers
1413  *      have been extracted. PPP should probably pass frames marked as for this
1414  *      layer.  [ie ARPHRD_ETHERTALK]
1415  */
1416 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1417                      struct packet_type *pt, struct net_device *orig_dev)
1418 {
1419         struct ddpehdr *ddp;
1420         struct sock *sock;
1421         struct atalk_iface *atif;
1422         struct sockaddr_at tosat;
1423         int origlen;
1424         __u16 len_hops;
1425
1426         if (!net_eq(dev_net(dev), &init_net))
1427                 goto drop;
1428
1429         /* Don't mangle buffer if shared */
1430         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1431                 goto out;
1432
1433         /* Size check and make sure header is contiguous */
1434         if (!pskb_may_pull(skb, sizeof(*ddp)))
1435                 goto drop;
1436
1437         ddp = ddp_hdr(skb);
1438
1439         len_hops = ntohs(ddp->deh_len_hops);
1440
1441         /* Trim buffer in case of stray trailing data */
1442         origlen = skb->len;
1443         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1444
1445         /*
1446          * Size check to see if ddp->deh_len was crap
1447          * (Otherwise we'll detonate most spectacularly
1448          * in the middle of atalk_checksum() or recvmsg()).
1449          */
1450         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1451                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1452                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1453                 goto drop;
1454         }
1455
1456         /*
1457          * Any checksums. Note we don't do htons() on this == is assumed to be
1458          * valid for net byte orders all over the networking code...
1459          */
1460         if (ddp->deh_sum &&
1461             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1462                 /* Not a valid AppleTalk frame - dustbin time */
1463                 goto drop;
1464
1465         /* Check the packet is aimed at us */
1466         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1467                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1468         else
1469                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1470
1471         if (!atif) {
1472                 /* Not ours, so we route the packet via the correct
1473                  * AppleTalk iface
1474                  */
1475                 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1476         }
1477
1478         /* if IP over DDP is not selected this code will be optimized out */
1479         if (is_ip_over_ddp(skb))
1480                 return handle_ip_over_ddp(skb);
1481         /*
1482          * Which socket - atalk_search_socket() looks for a *full match*
1483          * of the <net, node, port> tuple.
1484          */
1485         tosat.sat_addr.s_net  = ddp->deh_dnet;
1486         tosat.sat_addr.s_node = ddp->deh_dnode;
1487         tosat.sat_port        = ddp->deh_dport;
1488
1489         sock = atalk_search_socket(&tosat, atif);
1490         if (!sock) /* But not one of our sockets */
1491                 goto drop;
1492
1493         /* Queue packet (standard) */
1494         skb->sk = sock;
1495
1496         if (sock_queue_rcv_skb(sock, skb) < 0)
1497                 goto drop;
1498
1499         return NET_RX_SUCCESS;
1500
1501 drop:
1502         kfree_skb(skb);
1503 out:
1504         return NET_RX_DROP;
1505
1506 }
1507
1508 /*
1509  * Receive a LocalTalk frame. We make some demands on the caller here.
1510  * Caller must provide enough headroom on the packet to pull the short
1511  * header and append a long one.
1512  */
1513 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1514                      struct packet_type *pt, struct net_device *orig_dev)
1515 {
1516         if (!net_eq(dev_net(dev), &init_net))
1517                 goto freeit;
1518
1519         /* Expand any short form frames */
1520         if (skb_mac_header(skb)[2] == 1) {
1521                 struct ddpehdr *ddp;
1522                 /* Find our address */
1523                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1524
1525                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1526                         goto freeit;
1527
1528                 /* Don't mangle buffer if shared */
1529                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1530                         return 0;
1531
1532                 /*
1533                  * The push leaves us with a ddephdr not an shdr, and
1534                  * handily the port bytes in the right place preset.
1535                  */
1536                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1537
1538                 /* Now fill in the long header */
1539
1540                 /*
1541                  * These two first. The mac overlays the new source/dest
1542                  * network information so we MUST copy these before
1543                  * we write the network numbers !
1544                  */
1545
1546                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1547                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1548
1549                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1550                 ddp->deh_snet  = ap->s_net;
1551                 ddp->deh_sum   = 0;             /* No checksum */
1552                 /*
1553                  * Not sure about this bit...
1554                  */
1555                 /* Non routable, so force a drop if we slip up later */
1556                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1557         }
1558         skb_reset_transport_header(skb);
1559
1560         return atalk_rcv(skb, dev, pt, orig_dev);
1561 freeit:
1562         kfree_skb(skb);
1563         return 0;
1564 }
1565
1566 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1567                          size_t len)
1568 {
1569         struct sock *sk = sock->sk;
1570         struct atalk_sock *at = at_sk(sk);
1571         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1572         int flags = msg->msg_flags;
1573         int loopback = 0;
1574         struct sockaddr_at local_satalk, gsat;
1575         struct sk_buff *skb;
1576         struct net_device *dev;
1577         struct ddpehdr *ddp;
1578         int size;
1579         struct atalk_route *rt;
1580         int err;
1581
1582         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1583                 return -EINVAL;
1584
1585         if (len > DDP_MAXSZ)
1586                 return -EMSGSIZE;
1587
1588         lock_sock(sk);
1589         if (usat) {
1590                 err = -EBUSY;
1591                 if (sock_flag(sk, SOCK_ZAPPED))
1592                         if (atalk_autobind(sk) < 0)
1593                                 goto out;
1594
1595                 err = -EINVAL;
1596                 if (msg->msg_namelen < sizeof(*usat) ||
1597                     usat->sat_family != AF_APPLETALK)
1598                         goto out;
1599
1600                 err = -EPERM;
1601                 /* netatalk didn't implement this check */
1602                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1603                     !sock_flag(sk, SOCK_BROADCAST)) {
1604                         goto out;
1605                 }
1606         } else {
1607                 err = -ENOTCONN;
1608                 if (sk->sk_state != TCP_ESTABLISHED)
1609                         goto out;
1610                 usat = &local_satalk;
1611                 usat->sat_family      = AF_APPLETALK;
1612                 usat->sat_port        = at->dest_port;
1613                 usat->sat_addr.s_node = at->dest_node;
1614                 usat->sat_addr.s_net  = at->dest_net;
1615         }
1616
1617         /* Build a packet */
1618         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1619
1620         /* For headers */
1621         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1622
1623         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1624                 rt = atrtr_find(&usat->sat_addr);
1625         } else {
1626                 struct atalk_addr at_hint;
1627
1628                 at_hint.s_node = 0;
1629                 at_hint.s_net  = at->src_net;
1630
1631                 rt = atrtr_find(&at_hint);
1632         }
1633         err = ENETUNREACH;
1634         if (!rt)
1635                 goto out;
1636
1637         dev = rt->dev;
1638
1639         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1640                         sk, size, dev->name);
1641
1642         size += dev->hard_header_len;
1643         release_sock(sk);
1644         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1645         lock_sock(sk);
1646         if (!skb)
1647                 goto out;
1648
1649         skb->sk = sk;
1650         skb_reserve(skb, ddp_dl->header_length);
1651         skb_reserve(skb, dev->hard_header_len);
1652         skb->dev = dev;
1653
1654         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1655
1656         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1657         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1658         ddp->deh_dnet  = usat->sat_addr.s_net;
1659         ddp->deh_snet  = at->src_net;
1660         ddp->deh_dnode = usat->sat_addr.s_node;
1661         ddp->deh_snode = at->src_node;
1662         ddp->deh_dport = usat->sat_port;
1663         ddp->deh_sport = at->src_port;
1664
1665         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1666
1667         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1668         if (err) {
1669                 kfree_skb(skb);
1670                 err = -EFAULT;
1671                 goto out;
1672         }
1673
1674         if (sk->sk_no_check == 1)
1675                 ddp->deh_sum = 0;
1676         else
1677                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1678
1679         /*
1680          * Loopback broadcast packets to non gateway targets (ie routes
1681          * to group we are in)
1682          */
1683         if (ddp->deh_dnode == ATADDR_BCAST &&
1684             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1685                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1686
1687                 if (skb2) {
1688                         loopback = 1;
1689                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1690                         /*
1691                          * If it fails it is queued/sent above in the aarp queue
1692                          */
1693                         aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1694                 }
1695         }
1696
1697         if (dev->flags & IFF_LOOPBACK || loopback) {
1698                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1699                 /* loop back */
1700                 skb_orphan(skb);
1701                 if (ddp->deh_dnode == ATADDR_BCAST) {
1702                         struct atalk_addr at_lo;
1703
1704                         at_lo.s_node = 0;
1705                         at_lo.s_net  = 0;
1706
1707                         rt = atrtr_find(&at_lo);
1708                         if (!rt) {
1709                                 kfree_skb(skb);
1710                                 err = -ENETUNREACH;
1711                                 goto out;
1712                         }
1713                         dev = rt->dev;
1714                         skb->dev = dev;
1715                 }
1716                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1717         } else {
1718                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1719                 if (rt->flags & RTF_GATEWAY) {
1720                     gsat.sat_addr = rt->gateway;
1721                     usat = &gsat;
1722                 }
1723
1724                 /*
1725                  * If it fails it is queued/sent above in the aarp queue
1726                  */
1727                 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1728         }
1729         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1730
1731 out:
1732         release_sock(sk);
1733         return err ? : len;
1734 }
1735
1736 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1737                          size_t size, int flags)
1738 {
1739         struct sock *sk = sock->sk;
1740         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1741         struct ddpehdr *ddp;
1742         int copied = 0;
1743         int offset = 0;
1744         int err = 0;
1745         struct sk_buff *skb;
1746
1747         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1748                                                 flags & MSG_DONTWAIT, &err);
1749         lock_sock(sk);
1750
1751         if (!skb)
1752                 goto out;
1753
1754         /* FIXME: use skb->cb to be able to use shared skbs */
1755         ddp = ddp_hdr(skb);
1756         copied = ntohs(ddp->deh_len_hops) & 1023;
1757
1758         if (sk->sk_type != SOCK_RAW) {
1759                 offset = sizeof(*ddp);
1760                 copied -= offset;
1761         }
1762
1763         if (copied > size) {
1764                 copied = size;
1765                 msg->msg_flags |= MSG_TRUNC;
1766         }
1767         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1768
1769         if (!err) {
1770                 if (sat) {
1771                         sat->sat_family      = AF_APPLETALK;
1772                         sat->sat_port        = ddp->deh_sport;
1773                         sat->sat_addr.s_node = ddp->deh_snode;
1774                         sat->sat_addr.s_net  = ddp->deh_snet;
1775                 }
1776                 msg->msg_namelen = sizeof(*sat);
1777         }
1778
1779         skb_free_datagram(sk, skb);     /* Free the datagram. */
1780
1781 out:
1782         release_sock(sk);
1783         return err ? : copied;
1784 }
1785
1786
1787 /*
1788  * AppleTalk ioctl calls.
1789  */
1790 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1791 {
1792         int rc = -ENOIOCTLCMD;
1793         struct sock *sk = sock->sk;
1794         void __user *argp = (void __user *)arg;
1795
1796         switch (cmd) {
1797                 /* Protocol layer */
1798                 case TIOCOUTQ: {
1799                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1800
1801                         if (amount < 0)
1802                                 amount = 0;
1803                         rc = put_user(amount, (int __user *)argp);
1804                         break;
1805                 }
1806                 case TIOCINQ: {
1807                         /*
1808                          * These two are safe on a single CPU system as only
1809                          * user tasks fiddle here
1810                          */
1811                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1812                         long amount = 0;
1813
1814                         if (skb)
1815                                 amount = skb->len - sizeof(struct ddpehdr);
1816                         rc = put_user(amount, (int __user *)argp);
1817                         break;
1818                 }
1819                 case SIOCGSTAMP:
1820                         rc = sock_get_timestamp(sk, argp);
1821                         break;
1822                 case SIOCGSTAMPNS:
1823                         rc = sock_get_timestampns(sk, argp);
1824                         break;
1825                 /* Routing */
1826                 case SIOCADDRT:
1827                 case SIOCDELRT:
1828                         rc = -EPERM;
1829                         if (capable(CAP_NET_ADMIN))
1830                                 rc = atrtr_ioctl(cmd, argp);
1831                         break;
1832                 /* Interface */
1833                 case SIOCGIFADDR:
1834                 case SIOCSIFADDR:
1835                 case SIOCGIFBRDADDR:
1836                 case SIOCATALKDIFADDR:
1837                 case SIOCDIFADDR:
1838                 case SIOCSARP:          /* proxy AARP */
1839                 case SIOCDARP:          /* proxy AARP */
1840                         rtnl_lock();
1841                         rc = atif_ioctl(cmd, argp);
1842                         rtnl_unlock();
1843                         break;
1844         }
1845
1846         return rc;
1847 }
1848
1849
1850 #ifdef CONFIG_COMPAT
1851 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1852 {
1853         /*
1854          * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1855          * cannot handle it in common code. The data we access if ifreq
1856          * here is compatible, so we can simply call the native
1857          * handler.
1858          */
1859         if (cmd == SIOCATALKDIFADDR)
1860                 return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1861
1862         return -ENOIOCTLCMD;
1863 }
1864 #endif
1865
1866
1867 static const struct net_proto_family atalk_family_ops = {
1868         .family         = PF_APPLETALK,
1869         .create         = atalk_create,
1870         .owner          = THIS_MODULE,
1871 };
1872
1873 static const struct proto_ops atalk_dgram_ops = {
1874         .family         = PF_APPLETALK,
1875         .owner          = THIS_MODULE,
1876         .release        = atalk_release,
1877         .bind           = atalk_bind,
1878         .connect        = atalk_connect,
1879         .socketpair     = sock_no_socketpair,
1880         .accept         = sock_no_accept,
1881         .getname        = atalk_getname,
1882         .poll           = datagram_poll,
1883         .ioctl          = atalk_ioctl,
1884 #ifdef CONFIG_COMPAT
1885         .compat_ioctl   = atalk_compat_ioctl,
1886 #endif
1887         .listen         = sock_no_listen,
1888         .shutdown       = sock_no_shutdown,
1889         .setsockopt     = sock_no_setsockopt,
1890         .getsockopt     = sock_no_getsockopt,
1891         .sendmsg        = atalk_sendmsg,
1892         .recvmsg        = atalk_recvmsg,
1893         .mmap           = sock_no_mmap,
1894         .sendpage       = sock_no_sendpage,
1895 };
1896
1897 static struct notifier_block ddp_notifier = {
1898         .notifier_call  = ddp_device_event,
1899 };
1900
1901 static struct packet_type ltalk_packet_type __read_mostly = {
1902         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1903         .func           = ltalk_rcv,
1904 };
1905
1906 static struct packet_type ppptalk_packet_type __read_mostly = {
1907         .type           = cpu_to_be16(ETH_P_PPPTALK),
1908         .func           = atalk_rcv,
1909 };
1910
1911 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1912
1913 /* Export symbols for use by drivers when AppleTalk is a module */
1914 EXPORT_SYMBOL(atrtr_get_dev);
1915 EXPORT_SYMBOL(atalk_find_dev_addr);
1916
1917 static const char atalk_err_snap[] __initconst =
1918         KERN_CRIT "Unable to register DDP with SNAP.\n";
1919
1920 /* Called by proto.c on kernel start up */
1921 static int __init atalk_init(void)
1922 {
1923         int rc = proto_register(&ddp_proto, 0);
1924
1925         if (rc != 0)
1926                 goto out;
1927
1928         (void)sock_register(&atalk_family_ops);
1929         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1930         if (!ddp_dl)
1931                 printk(atalk_err_snap);
1932
1933         dev_add_pack(&ltalk_packet_type);
1934         dev_add_pack(&ppptalk_packet_type);
1935
1936         register_netdevice_notifier(&ddp_notifier);
1937         aarp_proto_init();
1938         atalk_proc_init();
1939         atalk_register_sysctl();
1940 out:
1941         return rc;
1942 }
1943 module_init(atalk_init);
1944
1945 /*
1946  * No explicit module reference count manipulation is needed in the
1947  * protocol. Socket layer sets module reference count for us
1948  * and interfaces reference counting is done
1949  * by the network device layer.
1950  *
1951  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1952  * sockets be closed from user space.
1953  */
1954 static void __exit atalk_exit(void)
1955 {
1956 #ifdef CONFIG_SYSCTL
1957         atalk_unregister_sysctl();
1958 #endif /* CONFIG_SYSCTL */
1959         atalk_proc_exit();
1960         aarp_cleanup_module();  /* General aarp clean-up. */
1961         unregister_netdevice_notifier(&ddp_notifier);
1962         dev_remove_pack(&ltalk_packet_type);
1963         dev_remove_pack(&ppptalk_packet_type);
1964         unregister_snap_client(ddp_dl);
1965         sock_unregister(PF_APPLETALK);
1966         proto_unregister(&ddp_proto);
1967 }
1968 module_exit(atalk_exit);
1969
1970 MODULE_LICENSE("GPL");
1971 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1972 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1973 MODULE_ALIAS_NETPROTO(PF_APPLETALK);