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
  65 struct datalink_proto *ddp_dl, *aarp_dl;
  66 static const struct proto_ops atalk_dgram_ops;
  67
  68 /**************************************************************************\
  69 *                                                                          *
  70 * Handlers for the socket list.                                            *
  71 *                                                                          *
  72 \**************************************************************************/
  73
  74 HLIST_HEAD(atalk_sockets);
  75 DEFINE_RWLOCK(atalk_sockets_lock);
  76
  77 static inline void __atalk_insert_socket(struct sock *sk)
  78 {
  79         sk_add_node(sk, &atalk_sockets);
  80 }
  81
  82 static inline void atalk_remove_socket(struct sock *sk)
  83 {
  84         write_lock_bh(&atalk_sockets_lock);
  85         sk_del_node_init(sk);
  86         write_unlock_bh(&atalk_sockets_lock);
  87 }
  88
  89 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  90                                         struct atalk_iface *atif)
  91 {
  92         struct sock *s;
  93         struct hlist_node *node;
  94
  95         read_lock_bh(&atalk_sockets_lock);
  96         sk_for_each(s, node, &atalk_sockets) {
  97                 struct atalk_sock *at = at_sk(s);
  98
  99                 if (to->sat_port != at->src_port)
 100                         continue;
 101
 102                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 103                     to->sat_addr.s_node == ATADDR_BCAST)
 104                         goto found;
 105
 106                 if (to->sat_addr.s_net == at->src_net &&
 107                     (to->sat_addr.s_node == at->src_node ||
 108                      to->sat_addr.s_node == ATADDR_BCAST ||
 109                      to->sat_addr.s_node == ATADDR_ANYNODE))
 110                         goto found;
 111
 112                 /* XXXX.0 -- we got a request for this router. make sure
 113                  * that the node is appropriately set. */
 114                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 115                     to->sat_addr.s_net != ATADDR_ANYNET &&
 116                     atif->address.s_node == at->src_node) {
 117                         to->sat_addr.s_node = atif->address.s_node;
 118                         goto found;
 119                 }
 120         }
 121         s = NULL;
 122 found:
 123         read_unlock_bh(&atalk_sockets_lock);
 124         return s;
 125 }
 126
 127 /**
 128  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 129  * @sk - socket to insert in the list if it is not there already
 130  * @sat - address to search for
 131  *
 132  * Try to find a socket matching ADDR in the socket list, if found then return
 133  * it. If not, insert SK into the socket list.
 134  *
 135  * This entire operation must execute atomically.
 136  */
 137 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 138                                                 struct sockaddr_at *sat)
 139 {
 140         struct sock *s;
 141         struct hlist_node *node;
 142         struct atalk_sock *at;
 143
 144         write_lock_bh(&atalk_sockets_lock);
 145         sk_for_each(s, node, &atalk_sockets) {
 146                 at = at_sk(s);
 147
 148                 if (at->src_net == sat->sat_addr.s_net &&
 149                     at->src_node == sat->sat_addr.s_node &&
 150                     at->src_port == sat->sat_port)
 151                         goto found;
 152         }
 153         s = NULL;
 154         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 155 found:
 156         write_unlock_bh(&atalk_sockets_lock);
 157         return s;
 158 }
 159
 160 static void atalk_destroy_timer(unsigned long data)
 161 {
 162         struct sock *sk = (struct sock *)data;
 163
 164         if (atomic_read(&sk->sk_wmem_alloc) ||
 165             atomic_read(&sk->sk_rmem_alloc)) {
 166                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 167                 add_timer(&sk->sk_timer);
 168         } else
 169                 sock_put(sk);
 170 }
 171
 172 static inline void atalk_destroy_socket(struct sock *sk)
 173 {
 174         atalk_remove_socket(sk);
 175         skb_queue_purge(&sk->sk_receive_queue);
 176
 177         if (atomic_read(&sk->sk_wmem_alloc) ||
 178             atomic_read(&sk->sk_rmem_alloc)) {
 179                 init_timer(&sk->sk_timer);
 180                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 181                 sk->sk_timer.function   = atalk_destroy_timer;
 182                 sk->sk_timer.data       = (unsigned long)sk;
 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         if (event == NETDEV_DOWN)
 650                 /* Discard any use of this */
 651                 atalk_dev_down(ptr);
 652
 653         return NOTIFY_DONE;
 654 }
 655
 656 /* ioctl calls. Shouldn't even need touching */
 657 /* Device configuration ioctl calls */
 658 static int atif_ioctl(int cmd, void __user *arg)
 659 {
 660         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 661         struct ifreq atreq;
 662         struct atalk_netrange *nr;
 663         struct sockaddr_at *sa;
 664         struct net_device *dev;
 665         struct atalk_iface *atif;
 666         int ct;
 667         int limit;
 668         struct rtentry rtdef;
 669         int add_route;
 670
 671         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 672                 return -EFAULT;
 673
 674         dev = __dev_get_by_name(atreq.ifr_name);
 675         if (!dev)
 676                 return -ENODEV;
 677
 678         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 679         atif = atalk_find_dev(dev);
 680
 681         switch (cmd) {
 682                 case SIOCSIFADDR:
 683                         if (!capable(CAP_NET_ADMIN))
 684                                 return -EPERM;
 685                         if (sa->sat_family != AF_APPLETALK)
 686                                 return -EINVAL;
 687                         if (dev->type != ARPHRD_ETHER &&
 688                             dev->type != ARPHRD_LOOPBACK &&
 689                             dev->type != ARPHRD_LOCALTLK &&
 690                             dev->type != ARPHRD_PPP)
 691                                 return -EPROTONOSUPPORT;
 692
 693                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 694                         add_route = 1;
 695
 696                         /*
 697                          * if this is a point-to-point iface, and we already
 698                          * have an iface for this AppleTalk address, then we
 699                          * should not add a route
 700                          */
 701                         if ((dev->flags & IFF_POINTOPOINT) &&
 702                             atalk_find_interface(sa->sat_addr.s_net,
 703                                                  sa->sat_addr.s_node)) {
 704                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 705                                                   "interface added with "
 706                                                   "existing address\n");
 707                                 add_route = 0;
 708                         }
 709
 710                         /*
 711                          * Phase 1 is fine on LocalTalk but we don't do
 712                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 713                          */
 714                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 715                                 return -EPROTONOSUPPORT;
 716                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 717                             sa->sat_addr.s_node == 254)
 718                                 return -EINVAL;
 719                         if (atif) {
 720                                 /* Already setting address */
 721                                 if (atif->status & ATIF_PROBE)
 722                                         return -EBUSY;
 723
 724                                 atif->address.s_net  = sa->sat_addr.s_net;
 725                                 atif->address.s_node = sa->sat_addr.s_node;
 726                                 atrtr_device_down(dev); /* Flush old routes */
 727                         } else {
 728                                 atif = atif_add_device(dev, &sa->sat_addr);
 729                                 if (!atif)
 730                                         return -ENOMEM;
 731                         }
 732                         atif->nets = *nr;
 733
 734                         /*
 735                          * Check if the chosen address is used. If so we
 736                          * error and atalkd will try another.
 737                          */
 738
 739                         if (!(dev->flags & IFF_LOOPBACK) &&
 740                             !(dev->flags & IFF_POINTOPOINT) &&
 741                             atif_probe_device(atif) < 0) {
 742                                 atif_drop_device(dev);
 743                                 return -EADDRINUSE;
 744                         }
 745
 746                         /* Hey it worked - add the direct routes */
 747                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 748                         sa->sat_family = AF_APPLETALK;
 749                         sa->sat_addr.s_net  = atif->address.s_net;
 750                         sa->sat_addr.s_node = atif->address.s_node;
 751                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 752                         rtdef.rt_flags = RTF_UP;
 753                         sa->sat_family = AF_APPLETALK;
 754                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 755                         if (dev->flags & IFF_LOOPBACK ||
 756                             dev->flags & IFF_POINTOPOINT)
 757                                 rtdef.rt_flags |= RTF_HOST;
 758
 759                         /* Routerless initial state */
 760                         if (nr->nr_firstnet == htons(0) &&
 761                             nr->nr_lastnet == htons(0xFFFE)) {
 762                                 sa->sat_addr.s_net = atif->address.s_net;
 763                                 atrtr_create(&rtdef, dev);
 764                                 atrtr_set_default(dev);
 765                         } else {
 766                                 limit = ntohs(nr->nr_lastnet);
 767                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 768                                         printk(KERN_WARNING "Too many routes/"
 769                                                             "iface.\n");
 770                                         return -EINVAL;
 771                                 }
 772                                 if (add_route)
 773                                         for (ct = ntohs(nr->nr_firstnet);
 774                                              ct <= limit; ct++) {
 775                                                 sa->sat_addr.s_net = htons(ct);
 776                                                 atrtr_create(&rtdef, dev);
 777                                         }
 778                         }
 779                         dev_mc_add(dev, aarp_mcast, 6, 1);
 780                         return 0;
 781
 782                 case SIOCGIFADDR:
 783                         if (!atif)
 784                                 return -EADDRNOTAVAIL;
 785
 786                         sa->sat_family = AF_APPLETALK;
 787                         sa->sat_addr = atif->address;
 788                         break;
 789
 790                 case SIOCGIFBRDADDR:
 791                         if (!atif)
 792                                 return -EADDRNOTAVAIL;
 793
 794                         sa->sat_family = AF_APPLETALK;
 795                         sa->sat_addr.s_net = atif->address.s_net;
 796                         sa->sat_addr.s_node = ATADDR_BCAST;
 797                         break;
 798
 799                 case SIOCATALKDIFADDR:
 800                 case SIOCDIFADDR:
 801                         if (!capable(CAP_NET_ADMIN))
 802                                 return -EPERM;
 803                         if (sa->sat_family != AF_APPLETALK)
 804                                 return -EINVAL;
 805                         atalk_dev_down(dev);
 806                         break;
 807
 808                 case SIOCSARP:
 809                         if (!capable(CAP_NET_ADMIN))
 810                                 return -EPERM;
 811                         if (sa->sat_family != AF_APPLETALK)
 812                                 return -EINVAL;
 813                         if (!atif)
 814                                 return -EADDRNOTAVAIL;
 815
 816                         /*
 817                          * for now, we only support proxy AARP on ELAP;
 818                          * we should be able to do it for LocalTalk, too.
 819                          */
 820                         if (dev->type != ARPHRD_ETHER)
 821                                 return -EPROTONOSUPPORT;
 822
 823                         /*
 824                          * atif points to the current interface on this network;
 825                          * we aren't concerned about its current status (at
 826                          * least for now), but it has all the settings about
 827                          * the network we're going to probe. Consequently, it
 828                          * must exist.
 829                          */
 830                         if (!atif)
 831                                 return -EADDRNOTAVAIL;
 832
 833                         nr = (struct atalk_netrange *)&(atif->nets);
 834                         /*
 835                          * Phase 1 is fine on Localtalk but we don't do
 836                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 837                          */
 838                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 839                                 return -EPROTONOSUPPORT;
 840
 841                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 842                             sa->sat_addr.s_node == 254)
 843                                 return -EINVAL;
 844
 845                         /*
 846                          * Check if the chosen address is used. If so we
 847                          * error and ATCP will try another.
 848                          */
 849                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 850                                 return -EADDRINUSE;
 851
 852                         /*
 853                          * We now have an address on the local network, and
 854                          * the AARP code will defend it for us until we take it
 855                          * down. We don't set up any routes right now, because
 856                          * ATCP will install them manually via SIOCADDRT.
 857                          */
 858                         break;
 859
 860                 case SIOCDARP:
 861                         if (!capable(CAP_NET_ADMIN))
 862                                 return -EPERM;
 863                         if (sa->sat_family != AF_APPLETALK)
 864                                 return -EINVAL;
 865                         if (!atif)
 866                                 return -EADDRNOTAVAIL;
 867
 868                         /* give to aarp module to remove proxy entry */
 869                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 870                         return 0;
 871         }
 872
 873         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 874 }
 875
 876 /* Routing ioctl() calls */
 877 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 878 {
 879         struct rtentry rt;
 880
 881         if (copy_from_user(&rt, arg, sizeof(rt)))
 882                 return -EFAULT;
 883
 884         switch (cmd) {
 885                 case SIOCDELRT:
 886                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 887                                 return -EINVAL;
 888                         return atrtr_delete(&((struct sockaddr_at *)
 889                                                 &rt.rt_dst)->sat_addr);
 890
 891                 case SIOCADDRT: {
 892                         struct net_device *dev = NULL;
 893                         if (rt.rt_dev) {
 894                                 char name[IFNAMSIZ];
 895                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 896                                         return -EFAULT;
 897                                 name[IFNAMSIZ-1] = '\0';
 898                                 dev = __dev_get_by_name(name);
 899                                 if (!dev)
 900                                         return -ENODEV;
 901                         }
 902                         return atrtr_create(&rt, dev);
 903                 }
 904         }
 905         return -EINVAL;
 906 }
 907
 908 /**************************************************************************\
 909 *                                                                          *
 910 * Handling for system calls applied via the various interfaces to an       *
 911 * AppleTalk socket object.                                                 *
 912 *                                                                          *
 913 \**************************************************************************/
 914
 915 /*
 916  * Checksum: This is 'optional'. It's quite likely also a good
 917  * candidate for assembler hackery 8)
 918  */
 919 static unsigned long atalk_sum_partial(const unsigned char *data,
 920                                        int len, unsigned long sum)
 921 {
 922         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 923         while (len--) {
 924                 sum += *data;
 925                 sum <<= 1;
 926                 if (sum & 0x10000) {
 927                         sum++;
 928                         sum &= 0xffff;
 929                 }
 930                 data++;
 931         }
 932         return sum;
 933 }
 934
 935 /*  Checksum skb data --  similar to skb_checksum  */
 936 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 937                                    int len, unsigned long sum)
 938 {
 939         int start = skb_headlen(skb);
 940         int i, copy;
 941
 942         /* checksum stuff in header space */
 943         if ( (copy = start - offset) > 0) {
 944                 if (copy > len)
 945                         copy = len;
 946                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 947                 if ( (len -= copy) == 0)
 948                         return sum;
 949
 950                 offset += copy;
 951         }
 952
 953         /* checksum stuff in frags */
 954         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 955                 int end;
 956
 957                 BUG_TRAP(start <= offset + len);
 958
 959                 end = start + skb_shinfo(skb)->frags[i].size;
 960                 if ((copy = end - offset) > 0) {
 961                         u8 *vaddr;
 962                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 963
 964                         if (copy > len)
 965                                 copy = len;
 966                         vaddr = kmap_skb_frag(frag);
 967                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 968                                                   offset - start, copy, sum);
 969                         kunmap_skb_frag(vaddr);
 970
 971                         if (!(len -= copy))
 972                                 return sum;
 973                         offset += copy;
 974                 }
 975                 start = end;
 976         }
 977
 978         if (skb_shinfo(skb)->frag_list) {
 979                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
 980
 981                 for (; list; list = list->next) {
 982                         int end;
 983
 984                         BUG_TRAP(start <= offset + len);
 985
 986                         end = start + list->len;
 987                         if ((copy = end - offset) > 0) {
 988                                 if (copy > len)
 989                                         copy = len;
 990                                 sum = atalk_sum_skb(list, offset - start,
 991                                                     copy, sum);
 992                                 if ((len -= copy) == 0)
 993                                         return sum;
 994                                 offset += copy;
 995                         }
 996                         start = end;
 997                 }
 998         }
 999
1000         BUG_ON(len > 0);
1001
1002         return sum;
1003 }
1004
1005 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1006 {
1007         unsigned long sum;
1008
1009         /* skip header 4 bytes */
1010         sum = atalk_sum_skb(skb, 4, len-4, 0);
1011
1012         /* Use 0xFFFF for 0. 0 itself means none */
1013         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1014 }
1015
1016 static struct proto ddp_proto = {
1017         .name     = "DDP",
1018         .owner    = THIS_MODULE,
1019         .obj_size = sizeof(struct atalk_sock),
1020 };
1021
1022 /*
1023  * Create a socket. Initialise the socket, blank the addresses
1024  * set the state.
1025  */
1026 static int atalk_create(struct socket *sock, int protocol)
1027 {
1028         struct sock *sk;
1029         int rc = -ESOCKTNOSUPPORT;
1030
1031         /*
1032          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1033          * and gives you the full ELAP frame. Should be handy for CAP 8)
1034          */
1035         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1036                 goto out;
1037         rc = -ENOMEM;
1038         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1039         if (!sk)
1040                 goto out;
1041         rc = 0;
1042         sock->ops = &atalk_dgram_ops;
1043         sock_init_data(sock, sk);
1044
1045         /* Checksums on by default */
1046         sock_set_flag(sk, SOCK_ZAPPED);
1047 out:
1048         return rc;
1049 }
1050
1051 /* Free a socket. No work needed */
1052 static int atalk_release(struct socket *sock)
1053 {
1054         struct sock *sk = sock->sk;
1055
1056         if (sk) {
1057                 sock_orphan(sk);
1058                 sock->sk = NULL;
1059                 atalk_destroy_socket(sk);
1060         }
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
1137         if (!sock_flag(sk, SOCK_ZAPPED) ||
1138             addr_len != sizeof(struct sockaddr_at))
1139                 return -EINVAL;
1140
1141         if (addr->sat_family != AF_APPLETALK)
1142                 return -EAFNOSUPPORT;
1143
1144         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1145                 struct atalk_addr *ap = atalk_find_primary();
1146
1147                 if (!ap)
1148                         return -EADDRNOTAVAIL;
1149
1150                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1151                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1152         } else {
1153                 if (!atalk_find_interface(addr->sat_addr.s_net,
1154                                           addr->sat_addr.s_node))
1155                         return -EADDRNOTAVAIL;
1156
1157                 at->src_net  = addr->sat_addr.s_net;
1158                 at->src_node = addr->sat_addr.s_node;
1159         }
1160
1161         if (addr->sat_port == ATADDR_ANYPORT) {
1162                 int n = atalk_pick_and_bind_port(sk, addr);
1163
1164                 if (n < 0)
1165                         return n;
1166         } else {
1167                 at->src_port = addr->sat_port;
1168
1169                 if (atalk_find_or_insert_socket(sk, addr))
1170                         return -EADDRINUSE;
1171         }
1172
1173         sock_reset_flag(sk, SOCK_ZAPPED);
1174         return 0;
1175 }
1176
1177 /* Set the address we talk to */
1178 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1179                          int addr_len, int flags)
1180 {
1181         struct sock *sk = sock->sk;
1182         struct atalk_sock *at = at_sk(sk);
1183         struct sockaddr_at *addr;
1184
1185         sk->sk_state   = TCP_CLOSE;
1186         sock->state = SS_UNCONNECTED;
1187
1188         if (addr_len != sizeof(*addr))
1189                 return -EINVAL;
1190
1191         addr = (struct sockaddr_at *)uaddr;
1192
1193         if (addr->sat_family != AF_APPLETALK)
1194                 return -EAFNOSUPPORT;
1195
1196         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1197             !sock_flag(sk, SOCK_BROADCAST)) {
1198 #if 1
1199                 printk(KERN_WARNING "%s is broken and did not set "
1200                                     "SO_BROADCAST. It will break when 2.2 is "
1201                                     "released.\n",
1202                         current->comm);
1203 #else
1204                 return -EACCES;
1205 #endif
1206         }
1207
1208         if (sock_flag(sk, SOCK_ZAPPED))
1209                 if (atalk_autobind(sk) < 0)
1210                         return -EBUSY;
1211
1212         if (!atrtr_get_dev(&addr->sat_addr))
1213                 return -ENETUNREACH;
1214
1215         at->dest_port = addr->sat_port;
1216         at->dest_net  = addr->sat_addr.s_net;
1217         at->dest_node = addr->sat_addr.s_node;
1218
1219         sock->state  = SS_CONNECTED;
1220         sk->sk_state = TCP_ESTABLISHED;
1221         return 0;
1222 }
1223
1224 /*
1225  * Find the name of an AppleTalk socket. Just copy the right
1226  * fields into the sockaddr.
1227  */
1228 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1229                          int *uaddr_len, int peer)
1230 {
1231         struct sockaddr_at sat;
1232         struct sock *sk = sock->sk;
1233         struct atalk_sock *at = at_sk(sk);
1234
1235         if (sock_flag(sk, SOCK_ZAPPED))
1236                 if (atalk_autobind(sk) < 0)
1237                         return -ENOBUFS;
1238
1239         *uaddr_len = sizeof(struct sockaddr_at);
1240
1241         if (peer) {
1242                 if (sk->sk_state != TCP_ESTABLISHED)
1243                         return -ENOTCONN;
1244
1245                 sat.sat_addr.s_net  = at->dest_net;
1246                 sat.sat_addr.s_node = at->dest_node;
1247                 sat.sat_port        = at->dest_port;
1248         } else {
1249                 sat.sat_addr.s_net  = at->src_net;
1250                 sat.sat_addr.s_node = at->src_node;
1251                 sat.sat_port        = at->src_port;
1252         }
1253
1254         sat.sat_family = AF_APPLETALK;
1255         memcpy(uaddr, &sat, sizeof(sat));
1256         return 0;
1257 }
1258
1259 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1260 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1261 {
1262         return skb->data[12] == 22;
1263 }
1264
1265 static int handle_ip_over_ddp(struct sk_buff *skb)
1266 {
1267         struct net_device *dev = __dev_get_by_name("ipddp0");
1268         struct net_device_stats *stats;
1269
1270         /* This needs to be able to handle ipddp"N" devices */
1271         if (!dev)
1272                 return -ENODEV;
1273
1274         skb->protocol = htons(ETH_P_IP);
1275         skb_pull(skb, 13);
1276         skb->dev   = dev;
1277         skb->h.raw = skb->data;
1278
1279         stats = dev->priv;
1280         stats->rx_packets++;
1281         stats->rx_bytes += skb->len + 13;
1282         netif_rx(skb);  /* Send the SKB up to a higher place. */
1283         return 0;
1284 }
1285 #else
1286 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1287 #define is_ip_over_ddp(skb) 0
1288 #define handle_ip_over_ddp(skb) 0
1289 #endif
1290
1291 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1292                                struct ddpehdr *ddp, __u16 len_hops,
1293                                int origlen)
1294 {
1295         struct atalk_route *rt;
1296         struct atalk_addr ta;
1297
1298         /*
1299          * Don't route multicast, etc., packets, or packets sent to "this
1300          * network"
1301          */
1302         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1303                 /*
1304                  * FIXME:
1305                  *
1306                  * Can it ever happen that a packet is from a PPP iface and
1307                  * needs to be broadcast onto the default network?
1308                  */
1309                 if (dev->type == ARPHRD_PPP)
1310                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1311                                           "packet received from PPP iface\n");
1312                 goto free_it;
1313         }
1314
1315         ta.s_net  = ddp->deh_dnet;
1316         ta.s_node = ddp->deh_dnode;
1317
1318         /* Route the packet */
1319         rt = atrtr_find(&ta);
1320         /* increment hops count */
1321         len_hops += 1 << 10;
1322         if (!rt || !(len_hops & (15 << 10)))
1323                 goto free_it;
1324
1325         /* FIXME: use skb->cb to be able to use shared skbs */
1326
1327         /*
1328          * Route goes through another gateway, so set the target to the
1329          * gateway instead.
1330          */
1331
1332         if (rt->flags & RTF_GATEWAY) {
1333                 ta.s_net  = rt->gateway.s_net;
1334                 ta.s_node = rt->gateway.s_node;
1335         }
1336
1337         /* Fix up skb->len field */
1338         skb_trim(skb, min_t(unsigned int, origlen,
1339                             (rt->dev->hard_header_len +
1340                              ddp_dl->header_length + (len_hops & 1023))));
1341
1342         /* FIXME: use skb->cb to be able to use shared skbs */
1343         ddp->deh_len_hops = htons(len_hops);
1344
1345         /*
1346          * Send the buffer onwards
1347          *
1348          * Now we must always be careful. If it's come from LocalTalk to
1349          * EtherTalk it might not fit
1350          *
1351          * Order matters here: If a packet has to be copied to make a new
1352          * headroom (rare hopefully) then it won't need unsharing.
1353          *
1354          * Note. ddp-> becomes invalid at the realloc.
1355          */
1356         if (skb_headroom(skb) < 22) {
1357                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1358                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1359                 kfree_skb(skb);
1360                 if (!nskb)
1361                         goto out;
1362                 skb = nskb;
1363         } else
1364                 skb = skb_unshare(skb, GFP_ATOMIC);
1365
1366         /*
1367          * If the buffer didn't vanish into the lack of space bitbucket we can
1368          * send it.
1369          */
1370         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1371                 goto free_it;
1372 out:
1373         return;
1374 free_it:
1375         kfree_skb(skb);
1376 }
1377
1378 /**
1379  *      atalk_rcv - Receive a packet (in skb) from device dev
1380  *      @skb - packet received
1381  *      @dev - network device where the packet comes from
1382  *      @pt - packet type
1383  *
1384  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1385  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1386  *      header, skb->len is the DDP length. The physical headers have been
1387  *      extracted. PPP should probably pass frames marked as for this layer.
1388  *      [ie ARPHRD_ETHERTALK]
1389  */
1390 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1391                      struct packet_type *pt, struct net_device *orig_dev)
1392 {
1393         struct ddpehdr *ddp;
1394         struct sock *sock;
1395         struct atalk_iface *atif;
1396         struct sockaddr_at tosat;
1397         int origlen;
1398         __u16 len_hops;
1399
1400         /* Don't mangle buffer if shared */
1401         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1402                 goto out;
1403
1404         /* Size check and make sure header is contiguous */
1405         if (!pskb_may_pull(skb, sizeof(*ddp)))
1406                 goto freeit;
1407
1408         ddp = ddp_hdr(skb);
1409
1410         len_hops = ntohs(ddp->deh_len_hops);
1411
1412         /* Trim buffer in case of stray trailing data */
1413         origlen = skb->len;
1414         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1415
1416         /*
1417          * Size check to see if ddp->deh_len was crap
1418          * (Otherwise we'll detonate most spectacularly
1419          * in the middle of recvmsg()).
1420          */
1421         if (skb->len < sizeof(*ddp))
1422                 goto freeit;
1423
1424         /*
1425          * Any checksums. Note we don't do htons() on this == is assumed to be
1426          * valid for net byte orders all over the networking code...
1427          */
1428         if (ddp->deh_sum &&
1429             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1430                 /* Not a valid AppleTalk frame - dustbin time */
1431                 goto freeit;
1432
1433         /* Check the packet is aimed at us */
1434         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1435                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1436         else
1437                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1438
1439         if (!atif) {
1440                 /* Not ours, so we route the packet via the correct
1441                  * AppleTalk iface
1442                  */
1443                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1444                 goto out;
1445         }
1446
1447         /* if IP over DDP is not selected this code will be optimized out */
1448         if (is_ip_over_ddp(skb))
1449                 return handle_ip_over_ddp(skb);
1450         /*
1451          * Which socket - atalk_search_socket() looks for a *full match*
1452          * of the <net, node, port> tuple.
1453          */
1454         tosat.sat_addr.s_net  = ddp->deh_dnet;
1455         tosat.sat_addr.s_node = ddp->deh_dnode;
1456         tosat.sat_port        = ddp->deh_dport;
1457
1458         sock = atalk_search_socket(&tosat, atif);
1459         if (!sock) /* But not one of our sockets */
1460                 goto freeit;
1461
1462         /* Queue packet (standard) */
1463         skb->sk = sock;
1464
1465         if (sock_queue_rcv_skb(sock, skb) < 0)
1466                 goto freeit;
1467 out:
1468         return 0;
1469 freeit:
1470         kfree_skb(skb);
1471         goto out;
1472 }
1473
1474 /*
1475  * Receive a LocalTalk frame. We make some demands on the caller here.
1476  * Caller must provide enough headroom on the packet to pull the short
1477  * header and append a long one.
1478  */
1479 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1480                      struct packet_type *pt, struct net_device *orig_dev)
1481 {
1482         /* Expand any short form frames */
1483         if (skb->mac.raw[2] == 1) {
1484                 struct ddpehdr *ddp;
1485                 /* Find our address */
1486                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1487
1488                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1489                         goto freeit;
1490
1491                 /* Don't mangle buffer if shared */
1492                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1493                         return 0;
1494
1495                 /*
1496                  * The push leaves us with a ddephdr not an shdr, and
1497                  * handily the port bytes in the right place preset.
1498                  */
1499                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1500
1501                 /* Now fill in the long header */
1502
1503                 /*
1504                  * These two first. The mac overlays the new source/dest
1505                  * network information so we MUST copy these before
1506                  * we write the network numbers !
1507                  */
1508
1509                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1510                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1511
1512                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1513                 ddp->deh_snet  = ap->s_net;
1514                 ddp->deh_sum   = 0;             /* No checksum */
1515                 /*
1516                  * Not sure about this bit...
1517                  */
1518                 /* Non routable, so force a drop if we slip up later */
1519                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1520         }
1521         skb->h.raw = skb->data;
1522
1523         return atalk_rcv(skb, dev, pt, orig_dev);
1524 freeit:
1525         kfree_skb(skb);
1526         return 0;
1527 }
1528
1529 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1530                          size_t len)
1531 {
1532         struct sock *sk = sock->sk;
1533         struct atalk_sock *at = at_sk(sk);
1534         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1535         int flags = msg->msg_flags;
1536         int loopback = 0;
1537         struct sockaddr_at local_satalk, gsat;
1538         struct sk_buff *skb;
1539         struct net_device *dev;
1540         struct ddpehdr *ddp;
1541         int size;
1542         struct atalk_route *rt;
1543         int err;
1544
1545         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1546                 return -EINVAL;
1547
1548         if (len > DDP_MAXSZ)
1549                 return -EMSGSIZE;
1550
1551         if (usat) {
1552                 if (sock_flag(sk, SOCK_ZAPPED))
1553                         if (atalk_autobind(sk) < 0)
1554                                 return -EBUSY;
1555
1556                 if (msg->msg_namelen < sizeof(*usat) ||
1557                     usat->sat_family != AF_APPLETALK)
1558                         return -EINVAL;
1559
1560                 /* netatalk doesn't implement this check */
1561                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1562                     !sock_flag(sk, SOCK_BROADCAST)) {
1563                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1564                                          "it will break before 2.2\n");
1565 #if 0
1566                         return -EPERM;
1567 #endif
1568                 }
1569         } else {
1570                 if (sk->sk_state != TCP_ESTABLISHED)
1571                         return -ENOTCONN;
1572                 usat = &local_satalk;
1573                 usat->sat_family      = AF_APPLETALK;
1574                 usat->sat_port        = at->dest_port;
1575                 usat->sat_addr.s_node = at->dest_node;
1576                 usat->sat_addr.s_net  = at->dest_net;
1577         }
1578
1579         /* Build a packet */
1580         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1581
1582         /* For headers */
1583         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1584
1585         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1586                 rt = atrtr_find(&usat->sat_addr);
1587                 dev = rt->dev;
1588         } else {
1589                 struct atalk_addr at_hint;
1590
1591                 at_hint.s_node = 0;
1592                 at_hint.s_net  = at->src_net;
1593
1594                 rt = atrtr_find(&at_hint);
1595                 dev = rt->dev;
1596         }
1597         if (!rt)
1598                 return -ENETUNREACH;
1599
1600         dev = rt->dev;
1601
1602         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1603                         sk, size, dev->name);
1604
1605         size += dev->hard_header_len;
1606         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1607         if (!skb)
1608                 return err;
1609
1610         skb->sk = sk;
1611         skb_reserve(skb, ddp_dl->header_length);
1612         skb_reserve(skb, dev->hard_header_len);
1613         skb->dev = dev;
1614
1615         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1616
1617         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1618         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1619         ddp->deh_dnet  = usat->sat_addr.s_net;
1620         ddp->deh_snet  = at->src_net;
1621         ddp->deh_dnode = usat->sat_addr.s_node;
1622         ddp->deh_snode = at->src_node;
1623         ddp->deh_dport = usat->sat_port;
1624         ddp->deh_sport = at->src_port;
1625
1626         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1627
1628         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1629         if (err) {
1630                 kfree_skb(skb);
1631                 return -EFAULT;
1632         }
1633
1634         if (sk->sk_no_check == 1)
1635                 ddp->deh_sum = 0;
1636         else
1637                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1638
1639         /*
1640          * Loopback broadcast packets to non gateway targets (ie routes
1641          * to group we are in)
1642          */
1643         if (ddp->deh_dnode == ATADDR_BCAST &&
1644             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1645                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1646
1647                 if (skb2) {
1648                         loopback = 1;
1649                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1650                         if (aarp_send_ddp(dev, skb2,
1651                                           &usat->sat_addr, NULL) == -1)
1652                                 kfree_skb(skb2);
1653                                 /* else queued/sent above in the aarp queue */
1654                 }
1655         }
1656
1657         if (dev->flags & IFF_LOOPBACK || loopback) {
1658                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1659                 /* loop back */
1660                 skb_orphan(skb);
1661                 if (ddp->deh_dnode == ATADDR_BCAST) {
1662                         struct atalk_addr at_lo;
1663
1664                         at_lo.s_node = 0;
1665                         at_lo.s_net  = 0;
1666
1667                         rt = atrtr_find(&at_lo);
1668                         if (!rt) {
1669                                 kfree_skb(skb);
1670                                 return -ENETUNREACH;
1671                         }
1672                         dev = rt->dev;
1673                         skb->dev = dev;
1674                 }
1675                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1676         } else {
1677                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1678                 if (rt->flags & RTF_GATEWAY) {
1679                     gsat.sat_addr = rt->gateway;
1680                     usat = &gsat;
1681                 }
1682
1683                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1684                         kfree_skb(skb);
1685                 /* else queued/sent above in the aarp queue */
1686         }
1687         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1688
1689         return len;
1690 }
1691
1692 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1693                          size_t size, int flags)
1694 {
1695         struct sock *sk = sock->sk;
1696         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1697         struct ddpehdr *ddp;
1698         int copied = 0;
1699         int offset = 0;
1700         int err = 0;
1701         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1702                                                 flags & MSG_DONTWAIT, &err);
1703         if (!skb)
1704                 return err;
1705
1706         /* FIXME: use skb->cb to be able to use shared skbs */
1707         ddp = ddp_hdr(skb);
1708         copied = ntohs(ddp->deh_len_hops) & 1023;
1709
1710         if (sk->sk_type != SOCK_RAW) {
1711                 offset = sizeof(*ddp);
1712                 copied -= offset;
1713         }
1714
1715         if (copied > size) {
1716                 copied = size;
1717                 msg->msg_flags |= MSG_TRUNC;
1718         }
1719         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1720
1721         if (!err) {
1722                 if (sat) {
1723                         sat->sat_family      = AF_APPLETALK;
1724                         sat->sat_port        = ddp->deh_sport;
1725                         sat->sat_addr.s_node = ddp->deh_snode;
1726                         sat->sat_addr.s_net  = ddp->deh_snet;
1727                 }
1728                 msg->msg_namelen = sizeof(*sat);
1729         }
1730
1731         skb_free_datagram(sk, skb);     /* Free the datagram. */
1732         return err ? : copied;
1733 }
1734
1735
1736 /*
1737  * AppleTalk ioctl calls.
1738  */
1739 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1740 {
1741         int rc = -ENOIOCTLCMD;
1742         struct sock *sk = sock->sk;
1743         void __user *argp = (void __user *)arg;
1744
1745         switch (cmd) {
1746                 /* Protocol layer */
1747                 case TIOCOUTQ: {
1748                         long amount = sk->sk_sndbuf -
1749                                       atomic_read(&sk->sk_wmem_alloc);
1750
1751                         if (amount < 0)
1752                                 amount = 0;
1753                         rc = put_user(amount, (int __user *)argp);
1754                         break;
1755                 }
1756                 case TIOCINQ: {
1757                         /*
1758                          * These two are safe on a single CPU system as only
1759                          * user tasks fiddle here
1760                          */
1761                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1762                         long amount = 0;
1763
1764                         if (skb)
1765                                 amount = skb->len - sizeof(struct ddpehdr);
1766                         rc = put_user(amount, (int __user *)argp);
1767                         break;
1768                 }
1769                 case SIOCGSTAMP:
1770                         rc = sock_get_timestamp(sk, argp);
1771                         break;
1772                 /* Routing */
1773                 case SIOCADDRT:
1774                 case SIOCDELRT:
1775                         rc = -EPERM;
1776                         if (capable(CAP_NET_ADMIN))
1777                                 rc = atrtr_ioctl(cmd, argp);
1778                         break;
1779                 /* Interface */
1780                 case SIOCGIFADDR:
1781                 case SIOCSIFADDR:
1782                 case SIOCGIFBRDADDR:
1783                 case SIOCATALKDIFADDR:
1784                 case SIOCDIFADDR:
1785                 case SIOCSARP:          /* proxy AARP */
1786                 case SIOCDARP:          /* proxy AARP */
1787                         rtnl_lock();
1788                         rc = atif_ioctl(cmd, argp);
1789                         rtnl_unlock();
1790                         break;
1791         }
1792
1793         return rc;
1794 }
1795
1796
1797 #ifdef CONFIG_COMPAT
1798 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1799 {
1800         /*
1801          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1802          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1803          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1804          * here so there is no generic SIOCPROTOPRIVATE translation in the
1805          * system.
1806          */
1807         return -ENOIOCTLCMD;
1808 }
1809 #endif
1810
1811
1812 static struct net_proto_family atalk_family_ops = {
1813         .family         = PF_APPLETALK,
1814         .create         = atalk_create,
1815         .owner          = THIS_MODULE,
1816 };
1817
1818 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1819         .family         = PF_APPLETALK,
1820         .owner          = THIS_MODULE,
1821         .release        = atalk_release,
1822         .bind           = atalk_bind,
1823         .connect        = atalk_connect,
1824         .socketpair     = sock_no_socketpair,
1825         .accept         = sock_no_accept,
1826         .getname        = atalk_getname,
1827         .poll           = datagram_poll,
1828         .ioctl          = atalk_ioctl,
1829 #ifdef CONFIG_COMPAT
1830         .compat_ioctl   = atalk_compat_ioctl,
1831 #endif
1832         .listen         = sock_no_listen,
1833         .shutdown       = sock_no_shutdown,
1834         .setsockopt     = sock_no_setsockopt,
1835         .getsockopt     = sock_no_getsockopt,
1836         .sendmsg        = atalk_sendmsg,
1837         .recvmsg        = atalk_recvmsg,
1838         .mmap           = sock_no_mmap,
1839         .sendpage       = sock_no_sendpage,
1840 };
1841
1842 #include <linux/smp_lock.h>
1843 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1844
1845 static struct notifier_block ddp_notifier = {
1846         .notifier_call  = ddp_device_event,
1847 };
1848
1849 static struct packet_type ltalk_packet_type = {
1850         .type           = __constant_htons(ETH_P_LOCALTALK),
1851         .func           = ltalk_rcv,
1852 };
1853
1854 static struct packet_type ppptalk_packet_type = {
1855         .type           = __constant_htons(ETH_P_PPPTALK),
1856         .func           = atalk_rcv,
1857 };
1858
1859 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1860
1861 /* Export symbols for use by drivers when AppleTalk is a module */
1862 EXPORT_SYMBOL(aarp_send_ddp);
1863 EXPORT_SYMBOL(atrtr_get_dev);
1864 EXPORT_SYMBOL(atalk_find_dev_addr);
1865
1866 static char atalk_err_snap[] __initdata =
1867         KERN_CRIT "Unable to register DDP with SNAP.\n";
1868
1869 /* Called by proto.c on kernel start up */
1870 static int __init atalk_init(void)
1871 {
1872         int rc = proto_register(&ddp_proto, 0);
1873
1874         if (rc != 0)
1875                 goto out;
1876
1877         (void)sock_register(&atalk_family_ops);
1878         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1879         if (!ddp_dl)
1880                 printk(atalk_err_snap);
1881
1882         dev_add_pack(&ltalk_packet_type);
1883         dev_add_pack(&ppptalk_packet_type);
1884
1885         register_netdevice_notifier(&ddp_notifier);
1886         aarp_proto_init();
1887         atalk_proc_init();
1888         atalk_register_sysctl();
1889 out:
1890         return rc;
1891 }
1892 module_init(atalk_init);
1893
1894 /*
1895  * No explicit module reference count manipulation is needed in the
1896  * protocol. Socket layer sets module reference count for us
1897  * and interfaces reference counting is done
1898  * by the network device layer.
1899  *
1900  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1901  * sockets be closed from user space.
1902  */
1903 static void __exit atalk_exit(void)
1904 {
1905 #ifdef CONFIG_SYSCTL
1906         atalk_unregister_sysctl();
1907 #endif /* CONFIG_SYSCTL */
1908         atalk_proc_exit();
1909         aarp_cleanup_module();  /* General aarp clean-up. */
1910         unregister_netdevice_notifier(&ddp_notifier);
1911         dev_remove_pack(&ltalk_packet_type);
1912         dev_remove_pack(&ppptalk_packet_type);
1913         unregister_snap_client(ddp_dl);
1914         sock_unregister(PF_APPLETALK);
1915         proto_unregister(&ddp_proto);
1916 }
1917 module_exit(atalk_exit);
1918
1919 MODULE_LICENSE("GPL");
1920 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1921 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1922 MODULE_ALIAS_NETPROTO(PF_APPLETALK);