net/appletalk/ddp.c

   1 /*
   2  *      DDP:    An implementation of the AppleTalk DDP protocol for
   3  *              Ethernet 'ELAP'.
   4  *
   5  *              Alan Cox  <Alan.Cox@linux.org>
   6  *
   7  *              With more than a little assistance from
   8  *
   9  *              Wesley Craig <netatalk@umich.edu>
  10  *
  11  *      Fixes:
  12  *              Neil Horman             :       Added missing device ioctls
  13  *              Michael Callahan        :       Made routing work
  14  *              Wesley Craig            :       Fix probing to listen to a
  15  *                                              passed node id.
  16  *              Alan Cox                :       Added send/recvmsg support
  17  *              Alan Cox                :       Moved at. to protinfo in
  18  *                                              socket.
  19  *              Alan Cox                :       Added firewall hooks.
  20  *              Alan Cox                :       Supports new ARPHRD_LOOPBACK
  21  *              Christer Weinigel       :       Routing and /proc fixes.
  22  *              Bradford Johnson        :       LocalTalk.
  23  *              Tom Dyas                :       Module support.
  24  *              Alan Cox                :       Hooks for PPP (based on the
  25  *                                              LocalTalk hook).
  26  *              Alan Cox                :       Posix bits
  27  *              Alan Cox/Mike Freeman   :       Possible fix to NBP problems
  28  *              Bradford Johnson        :       IP-over-DDP (experimental)
  29  *              Jay Schulist            :       Moved IP-over-DDP to its own
  30  *                                              driver file. (ipddp.c & ipddp.h)
  31  *              Jay Schulist            :       Made work as module with
  32  *                                              AppleTalk drivers, cleaned it.
  33  *              Rob Newberry            :       Added proxy AARP and AARP
  34  *                                              procfs, moved probing to AARP
  35  *                                              module.
  36  *              Adrian Sun/
  37  *              Michael Zuelsdorff      :       fix for net.0 packets. don't
  38  *                                              allow illegal ether/tokentalk
  39  *                                              port assignment. we lose a
  40  *                                              valid localtalk port as a
  41  *                                              result.
  42  *              Arnaldo C. de Melo      :       Cleanup, in preparation for
  43  *                                              shared skb support 8)
  44  *              Arnaldo C. de Melo      :       Move proc stuff to atalk_proc.c,
  45  *                                              use seq_file
  46  *
  47  *              This program is free software; you can redistribute it and/or
  48  *              modify it under the terms of the GNU General Public License
  49  *              as published by the Free Software Foundation; either version
  50  *              2 of the License, or (at your option) any later version.
  51  *
  52  */
  53
  54 #include <linux/config.h>
  55 #include <linux/module.h>
  56 #include <linux/tcp.h>
  57 #include <linux/if_arp.h>
  58 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
  59 #include <net/datalink.h>
  60 #include <net/psnap.h>
  61 #include <net/sock.h>
  62 #include <net/route.h>
  63 #include <linux/atalk.h>
  64
  65 struct datalink_proto *ddp_dl, *aarp_dl;
  66 static struct proto_ops atalk_dgram_ops;
  67
  68 /**************************************************************************\
  69 *                                                                          *
  70 * Handlers for the socket list.                                            *
  71 *                                                                          *
  72 \**************************************************************************/
  73
  74 HLIST_HEAD(atalk_sockets);
  75 DEFINE_RWLOCK(atalk_sockets_lock);
  76
  77 static inline void __atalk_insert_socket(struct sock *sk)
  78 {
  79         sk_add_node(sk, &atalk_sockets);
  80 }
  81
  82 static inline void atalk_remove_socket(struct sock *sk)
  83 {
  84         write_lock_bh(&atalk_sockets_lock);
  85         sk_del_node_init(sk);
  86         write_unlock_bh(&atalk_sockets_lock);
  87 }
  88
  89 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  90                                         struct atalk_iface *atif)
  91 {
  92         struct sock *s;
  93         struct hlist_node *node;
  94
  95         read_lock_bh(&atalk_sockets_lock);
  96         sk_for_each(s, node, &atalk_sockets) {
  97                 struct atalk_sock *at = at_sk(s);
  98
  99                 if (to->sat_port != at->src_port)
 100                         continue;
 101
 102                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 103                     to->sat_addr.s_node == ATADDR_BCAST &&
 104                     at->src_net == atif->address.s_net)
 105                         goto found;
 106
 107                 if (to->sat_addr.s_net == at->src_net &&
 108                     (to->sat_addr.s_node == at->src_node ||
 109                      to->sat_addr.s_node == ATADDR_BCAST ||
 110                      to->sat_addr.s_node == ATADDR_ANYNODE))
 111                         goto found;
 112
 113                 /* XXXX.0 -- we got a request for this router. make sure
 114                  * that the node is appropriately set. */
 115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 116                     to->sat_addr.s_net != ATADDR_ANYNET &&
 117                     atif->address.s_node == at->src_node) {
 118                         to->sat_addr.s_node = atif->address.s_node;
 119                         goto found;
 120                 }
 121         }
 122         s = NULL;
 123 found:
 124         read_unlock_bh(&atalk_sockets_lock);
 125         return s;
 126 }
 127
 128 /**
 129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 130  * @sk - socket to insert in the list if it is not there already
 131  * @sat - address to search for
 132  *
 133  * Try to find a socket matching ADDR in the socket list, if found then return
 134  * it. If not, insert SK into the socket list.
 135  *
 136  * This entire operation must execute atomically.
 137  */
 138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 139                                                 struct sockaddr_at *sat)
 140 {
 141         struct sock *s;
 142         struct hlist_node *node;
 143         struct atalk_sock *at;
 144
 145         write_lock_bh(&atalk_sockets_lock);
 146         sk_for_each(s, node, &atalk_sockets) {
 147                 at = at_sk(s);
 148
 149                 if (at->src_net == sat->sat_addr.s_net &&
 150                     at->src_node == sat->sat_addr.s_node &&
 151                     at->src_port == sat->sat_port)
 152                         goto found;
 153         }
 154         s = NULL;
 155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 156 found:
 157         write_unlock_bh(&atalk_sockets_lock);
 158         return s;
 159 }
 160
 161 static void atalk_destroy_timer(unsigned long data)
 162 {
 163         struct sock *sk = (struct sock *)data;
 164
 165         if (atomic_read(&sk->sk_wmem_alloc) ||
 166             atomic_read(&sk->sk_rmem_alloc)) {
 167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 168                 add_timer(&sk->sk_timer);
 169         } else
 170                 sock_put(sk);
 171 }
 172
 173 static inline void atalk_destroy_socket(struct sock *sk)
 174 {
 175         atalk_remove_socket(sk);
 176         skb_queue_purge(&sk->sk_receive_queue);
 177
 178         if (atomic_read(&sk->sk_wmem_alloc) ||
 179             atomic_read(&sk->sk_rmem_alloc)) {
 180                 init_timer(&sk->sk_timer);
 181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 182                 sk->sk_timer.function   = atalk_destroy_timer;
 183                 sk->sk_timer.data       = (unsigned long)sk;
 184                 add_timer(&sk->sk_timer);
 185         } else
 186                 sock_put(sk);
 187 }
 188
 189 /**************************************************************************\
 190 *                                                                          *
 191 * Routing tables for the AppleTalk socket layer.                           *
 192 *                                                                          *
 193 \**************************************************************************/
 194
 195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 196 struct atalk_route *atalk_routes;
 197 DEFINE_RWLOCK(atalk_routes_lock);
 198
 199 struct atalk_iface *atalk_interfaces;
 200 DEFINE_RWLOCK(atalk_interfaces_lock);
 201
 202 /* For probing devices or in a routerless network */
 203 struct atalk_route atrtr_default;
 204
 205 /* AppleTalk interface control */
 206 /*
 207  * Drop a device. Doesn't drop any of its routes - that is the caller's
 208  * problem. Called when we down the interface or delete the address.
 209  */
 210 static void atif_drop_device(struct net_device *dev)
 211 {
 212         struct atalk_iface **iface = &atalk_interfaces;
 213         struct atalk_iface *tmp;
 214
 215         write_lock_bh(&atalk_interfaces_lock);
 216         while ((tmp = *iface) != NULL) {
 217                 if (tmp->dev == dev) {
 218                         *iface = tmp->next;
 219                         dev_put(dev);
 220                         kfree(tmp);
 221                         dev->atalk_ptr = NULL;
 222                 } else
 223                         iface = &tmp->next;
 224         }
 225         write_unlock_bh(&atalk_interfaces_lock);
 226 }
 227
 228 static struct atalk_iface *atif_add_device(struct net_device *dev,
 229                                            struct atalk_addr *sa)
 230 {
 231         struct atalk_iface *iface = kmalloc(sizeof(*iface), GFP_KERNEL);
 232
 233         if (!iface)
 234                 goto out;
 235
 236         memset(iface, 0, sizeof(*iface));
 237         dev_hold(dev);
 238         iface->dev = dev;
 239         dev->atalk_ptr = iface;
 240         iface->address = *sa;
 241         iface->status = 0;
 242
 243         write_lock_bh(&atalk_interfaces_lock);
 244         iface->next = atalk_interfaces;
 245         atalk_interfaces = iface;
 246         write_unlock_bh(&atalk_interfaces_lock);
 247 out:
 248         return iface;
 249 }
 250
 251 /* Perform phase 2 AARP probing on our tentative address */
 252 static int atif_probe_device(struct atalk_iface *atif)
 253 {
 254         int netrange = ntohs(atif->nets.nr_lastnet) -
 255                         ntohs(atif->nets.nr_firstnet) + 1;
 256         int probe_net = ntohs(atif->address.s_net);
 257         int probe_node = atif->address.s_node;
 258         int netct, nodect;
 259
 260         /* Offset the network we start probing with */
 261         if (probe_net == ATADDR_ANYNET) {
 262                 probe_net = ntohs(atif->nets.nr_firstnet);
 263                 if (netrange)
 264                         probe_net += jiffies % netrange;
 265         }
 266         if (probe_node == ATADDR_ANYNODE)
 267                 probe_node = jiffies & 0xFF;
 268
 269         /* Scan the networks */
 270         atif->status |= ATIF_PROBE;
 271         for (netct = 0; netct <= netrange; netct++) {
 272                 /* Sweep the available nodes from a given start */
 273                 atif->address.s_net = htons(probe_net);
 274                 for (nodect = 0; nodect < 256; nodect++) {
 275                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 276                         if (atif->address.s_node > 0 &&
 277                             atif->address.s_node < 254) {
 278                                 /* Probe a proposed address */
 279                                 aarp_probe_network(atif);
 280
 281                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 282                                         atif->status &= ~ATIF_PROBE;
 283                                         return 0;
 284                                 }
 285                         }
 286                         atif->status &= ~ATIF_PROBE_FAIL;
 287                 }
 288                 probe_net++;
 289                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 290                         probe_net = ntohs(atif->nets.nr_firstnet);
 291         }
 292         atif->status &= ~ATIF_PROBE;
 293
 294         return -EADDRINUSE;     /* Network is full... */
 295 }
 296
 297
 298 /* Perform AARP probing for a proxy address */
 299 static int atif_proxy_probe_device(struct atalk_iface *atif,
 300                                    struct atalk_addr* proxy_addr)
 301 {
 302         int netrange = ntohs(atif->nets.nr_lastnet) -
 303                         ntohs(atif->nets.nr_firstnet) + 1;
 304         /* we probe the interface's network */
 305         int probe_net = ntohs(atif->address.s_net);
 306         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 307         int netct, nodect;
 308
 309         /* Offset the network we start probing with */
 310         if (probe_net == ATADDR_ANYNET) {
 311                 probe_net = ntohs(atif->nets.nr_firstnet);
 312                 if (netrange)
 313                         probe_net += jiffies % netrange;
 314         }
 315
 316         if (probe_node == ATADDR_ANYNODE)
 317                 probe_node = jiffies & 0xFF;
 318
 319         /* Scan the networks */
 320         for (netct = 0; netct <= netrange; netct++) {
 321                 /* Sweep the available nodes from a given start */
 322                 proxy_addr->s_net = htons(probe_net);
 323                 for (nodect = 0; nodect < 256; nodect++) {
 324                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 325                         if (proxy_addr->s_node > 0 &&
 326                             proxy_addr->s_node < 254) {
 327                                 /* Tell AARP to probe a proposed address */
 328                                 int ret = aarp_proxy_probe_network(atif,
 329                                                                     proxy_addr);
 330
 331                                 if (ret != -EADDRINUSE)
 332                                         return ret;
 333                         }
 334                 }
 335                 probe_net++;
 336                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 337                         probe_net = ntohs(atif->nets.nr_firstnet);
 338         }
 339
 340         return -EADDRINUSE;     /* Network is full... */
 341 }
 342
 343
 344 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 345 {
 346         struct atalk_iface *iface = dev->atalk_ptr;
 347         return iface ? &iface->address : NULL;
 348 }
 349
 350 static struct atalk_addr *atalk_find_primary(void)
 351 {
 352         struct atalk_iface *fiface = NULL;
 353         struct atalk_addr *retval;
 354         struct atalk_iface *iface;
 355
 356         /*
 357          * Return a point-to-point interface only if
 358          * there is no non-ptp interface available.
 359          */
 360         read_lock_bh(&atalk_interfaces_lock);
 361         for (iface = atalk_interfaces; iface; iface = iface->next) {
 362                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 363                         fiface = iface;
 364                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 365                         retval = &iface->address;
 366                         goto out;
 367                 }
 368         }
 369
 370         if (fiface)
 371                 retval = &fiface->address;
 372         else if (atalk_interfaces)
 373                 retval = &atalk_interfaces->address;
 374         else
 375                 retval = NULL;
 376 out:
 377         read_unlock_bh(&atalk_interfaces_lock);
 378         return retval;
 379 }
 380
 381 /*
 382  * Find a match for 'any network' - ie any of our interfaces with that
 383  * node number will do just nicely.
 384  */
 385 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 386 {
 387         struct atalk_iface *iface = dev->atalk_ptr;
 388
 389         if (!iface || iface->status & ATIF_PROBE)
 390                 goto out_err;
 391
 392         if (node != ATADDR_BCAST &&
 393             iface->address.s_node != node &&
 394             node != ATADDR_ANYNODE)
 395                 goto out_err;
 396 out:
 397         return iface;
 398 out_err:
 399         iface = NULL;
 400         goto out;
 401 }
 402
 403 /* Find a match for a specific network:node pair */
 404 static struct atalk_iface *atalk_find_interface(int net, int node)
 405 {
 406         struct atalk_iface *iface;
 407
 408         read_lock_bh(&atalk_interfaces_lock);
 409         for (iface = atalk_interfaces; iface; iface = iface->next) {
 410                 if ((node == ATADDR_BCAST ||
 411                      node == ATADDR_ANYNODE ||
 412                      iface->address.s_node == node) &&
 413                     iface->address.s_net == net &&
 414                     !(iface->status & ATIF_PROBE))
 415                         break;
 416
 417                 /* XXXX.0 -- net.0 returns the iface associated with net */
 418                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 419                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 420                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 421                         break;
 422         }
 423         read_unlock_bh(&atalk_interfaces_lock);
 424         return iface;
 425 }
 426
 427
 428 /*
 429  * Find a route for an AppleTalk packet. This ought to get cached in
 430  * the socket (later on...). We know about host routes and the fact
 431  * that a route must be direct to broadcast.
 432  */
 433 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 434 {
 435         /*
 436          * we must search through all routes unless we find a
 437          * host route, because some host routes might overlap
 438          * network routes
 439          */
 440         struct atalk_route *net_route = NULL;
 441         struct atalk_route *r;
 442
 443         read_lock_bh(&atalk_routes_lock);
 444         for (r = atalk_routes; r; r = r->next) {
 445                 if (!(r->flags & RTF_UP))
 446                         continue;
 447
 448                 if (r->target.s_net == target->s_net) {
 449                         if (r->flags & RTF_HOST) {
 450                                 /*
 451                                  * if this host route is for the target,
 452                                  * the we're done
 453                                  */
 454                                 if (r->target.s_node == target->s_node)
 455                                         goto out;
 456                         } else
 457                                 /*
 458                                  * this route will work if there isn't a
 459                                  * direct host route, so cache it
 460                                  */
 461                                 net_route = r;
 462                 }
 463         }
 464
 465         /*
 466          * if we found a network route but not a direct host
 467          * route, then return it
 468          */
 469         if (net_route)
 470                 r = net_route;
 471         else if (atrtr_default.dev)
 472                 r = &atrtr_default;
 473         else /* No route can be found */
 474                 r = NULL;
 475 out:
 476         read_unlock_bh(&atalk_routes_lock);
 477         return r;
 478 }
 479
 480
 481 /*
 482  * Given an AppleTalk network, find the device to use. This can be
 483  * a simple lookup.
 484  */
 485 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 486 {
 487         struct atalk_route *atr = atrtr_find(sa);
 488         return atr ? atr->dev : NULL;
 489 }
 490
 491 /* Set up a default router */
 492 static void atrtr_set_default(struct net_device *dev)
 493 {
 494         atrtr_default.dev            = dev;
 495         atrtr_default.flags          = RTF_UP;
 496         atrtr_default.gateway.s_net  = htons(0);
 497         atrtr_default.gateway.s_node = 0;
 498 }
 499
 500 /*
 501  * Add a router. Basically make sure it looks valid and stuff the
 502  * entry in the list. While it uses netranges we always set them to one
 503  * entry to work like netatalk.
 504  */
 505 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 506 {
 507         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 508         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 509         struct atalk_route *rt;
 510         struct atalk_iface *iface, *riface;
 511         int retval = -EINVAL;
 512
 513         /*
 514          * Fixme: Raise/Lower a routing change semaphore for these
 515          * operations.
 516          */
 517
 518         /* Validate the request */
 519         if (ta->sat_family != AF_APPLETALK ||
 520             (!devhint && ga->sat_family != AF_APPLETALK))
 521                 goto out;
 522
 523         /* Now walk the routing table and make our decisions */
 524         write_lock_bh(&atalk_routes_lock);
 525         for (rt = atalk_routes; rt; rt = rt->next) {
 526                 if (r->rt_flags != rt->flags)
 527                         continue;
 528
 529                 if (ta->sat_addr.s_net == rt->target.s_net) {
 530                         if (!(rt->flags & RTF_HOST))
 531                                 break;
 532                         if (ta->sat_addr.s_node == rt->target.s_node)
 533                                 break;
 534                 }
 535         }
 536
 537         if (!devhint) {
 538                 riface = NULL;
 539
 540                 read_lock_bh(&atalk_interfaces_lock);
 541                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 542                         if (!riface &&
 543                             ntohs(ga->sat_addr.s_net) >=
 544                                         ntohs(iface->nets.nr_firstnet) &&
 545                             ntohs(ga->sat_addr.s_net) <=
 546                                         ntohs(iface->nets.nr_lastnet))
 547                                 riface = iface;
 548
 549                         if (ga->sat_addr.s_net == iface->address.s_net &&
 550                             ga->sat_addr.s_node == iface->address.s_node)
 551                                 riface = iface;
 552                 }
 553                 read_unlock_bh(&atalk_interfaces_lock);
 554
 555                 retval = -ENETUNREACH;
 556                 if (!riface)
 557                         goto out_unlock;
 558
 559                 devhint = riface->dev;
 560         }
 561
 562         if (!rt) {
 563                 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
 564
 565                 retval = -ENOBUFS;
 566                 if (!rt)
 567                         goto out_unlock;
 568                 memset(rt, 0, sizeof(*rt));
 569
 570                 rt->next = atalk_routes;
 571                 atalk_routes = rt;
 572         }
 573
 574         /* Fill in the routing entry */
 575         rt->target  = ta->sat_addr;
 576         rt->dev     = devhint;
 577         rt->flags   = r->rt_flags;
 578         rt->gateway = ga->sat_addr;
 579
 580         retval = 0;
 581 out_unlock:
 582         write_unlock_bh(&atalk_routes_lock);
 583 out:
 584         return retval;
 585 }
 586
 587 /* Delete a route. Find it and discard it */
 588 static int atrtr_delete(struct atalk_addr * addr)
 589 {
 590         struct atalk_route **r = &atalk_routes;
 591         int retval = 0;
 592         struct atalk_route *tmp;
 593
 594         write_lock_bh(&atalk_routes_lock);
 595         while ((tmp = *r) != NULL) {
 596                 if (tmp->target.s_net == addr->s_net &&
 597                     (!(tmp->flags&RTF_GATEWAY) ||
 598                      tmp->target.s_node == addr->s_node)) {
 599                         *r = tmp->next;
 600                         dev_put(tmp->dev);
 601                         kfree(tmp);
 602                         goto out;
 603                 }
 604                 r = &tmp->next;
 605         }
 606         retval = -ENOENT;
 607 out:
 608         write_unlock_bh(&atalk_routes_lock);
 609         return retval;
 610 }
 611
 612 /*
 613  * Called when a device is downed. Just throw away any routes
 614  * via it.
 615  */
 616 static void atrtr_device_down(struct net_device *dev)
 617 {
 618         struct atalk_route **r = &atalk_routes;
 619         struct atalk_route *tmp;
 620
 621         write_lock_bh(&atalk_routes_lock);
 622         while ((tmp = *r) != NULL) {
 623                 if (tmp->dev == dev) {
 624                         *r = tmp->next;
 625                         dev_put(dev);
 626                         kfree(tmp);
 627                 } else
 628                         r = &tmp->next;
 629         }
 630         write_unlock_bh(&atalk_routes_lock);
 631
 632         if (atrtr_default.dev == dev)
 633                 atrtr_set_default(NULL);
 634 }
 635
 636 /* Actually down the interface */
 637 static inline void atalk_dev_down(struct net_device *dev)
 638 {
 639         atrtr_device_down(dev); /* Remove all routes for the device */
 640         aarp_device_down(dev);  /* Remove AARP entries for the device */
 641         atif_drop_device(dev);  /* Remove the device */
 642 }
 643
 644 /*
 645  * A device event has occurred. Watch for devices going down and
 646  * delete our use of them (iface and route).
 647  */
 648 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 649                             void *ptr)
 650 {
 651         if (event == NETDEV_DOWN)
 652                 /* Discard any use of this */
 653                 atalk_dev_down(ptr);
 654
 655         return NOTIFY_DONE;
 656 }
 657
 658 /* ioctl calls. Shouldn't even need touching */
 659 /* Device configuration ioctl calls */
 660 static int atif_ioctl(int cmd, void __user *arg)
 661 {
 662         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 663         struct ifreq atreq;
 664         struct atalk_netrange *nr;
 665         struct sockaddr_at *sa;
 666         struct net_device *dev;
 667         struct atalk_iface *atif;
 668         int ct;
 669         int limit;
 670         struct rtentry rtdef;
 671         int add_route;
 672
 673         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 674                 return -EFAULT;
 675
 676         dev = __dev_get_by_name(atreq.ifr_name);
 677         if (!dev)
 678                 return -ENODEV;
 679
 680         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 681         atif = atalk_find_dev(dev);
 682
 683         switch (cmd) {
 684                 case SIOCSIFADDR:
 685                         if (!capable(CAP_NET_ADMIN))
 686                                 return -EPERM;
 687                         if (sa->sat_family != AF_APPLETALK)
 688                                 return -EINVAL;
 689                         if (dev->type != ARPHRD_ETHER &&
 690                             dev->type != ARPHRD_LOOPBACK &&
 691                             dev->type != ARPHRD_LOCALTLK &&
 692                             dev->type != ARPHRD_PPP)
 693                                 return -EPROTONOSUPPORT;
 694
 695                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 696                         add_route = 1;
 697
 698                         /*
 699                          * if this is a point-to-point iface, and we already
 700                          * have an iface for this AppleTalk address, then we
 701                          * should not add a route
 702                          */
 703                         if ((dev->flags & IFF_POINTOPOINT) &&
 704                             atalk_find_interface(sa->sat_addr.s_net,
 705                                                  sa->sat_addr.s_node)) {
 706                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 707                                                   "interface added with "
 708                                                   "existing address\n");
 709                                 add_route = 0;
 710                         }
 711
 712                         /*
 713                          * Phase 1 is fine on LocalTalk but we don't do
 714                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 715                          */
 716                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 717                                 return -EPROTONOSUPPORT;
 718                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 719                             sa->sat_addr.s_node == 254)
 720                                 return -EINVAL;
 721                         if (atif) {
 722                                 /* Already setting address */
 723                                 if (atif->status & ATIF_PROBE)
 724                                         return -EBUSY;
 725
 726                                 atif->address.s_net  = sa->sat_addr.s_net;
 727                                 atif->address.s_node = sa->sat_addr.s_node;
 728                                 atrtr_device_down(dev); /* Flush old routes */
 729                         } else {
 730                                 atif = atif_add_device(dev, &sa->sat_addr);
 731                                 if (!atif)
 732                                         return -ENOMEM;
 733                         }
 734                         atif->nets = *nr;
 735
 736                         /*
 737                          * Check if the chosen address is used. If so we
 738                          * error and atalkd will try another.
 739                          */
 740
 741                         if (!(dev->flags & IFF_LOOPBACK) &&
 742                             !(dev->flags & IFF_POINTOPOINT) &&
 743                             atif_probe_device(atif) < 0) {
 744                                 atif_drop_device(dev);
 745                                 return -EADDRINUSE;
 746                         }
 747
 748                         /* Hey it worked - add the direct routes */
 749                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 750                         sa->sat_family = AF_APPLETALK;
 751                         sa->sat_addr.s_net  = atif->address.s_net;
 752                         sa->sat_addr.s_node = atif->address.s_node;
 753                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 754                         rtdef.rt_flags = RTF_UP;
 755                         sa->sat_family = AF_APPLETALK;
 756                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 757                         if (dev->flags & IFF_LOOPBACK ||
 758                             dev->flags & IFF_POINTOPOINT)
 759                                 rtdef.rt_flags |= RTF_HOST;
 760
 761                         /* Routerless initial state */
 762                         if (nr->nr_firstnet == htons(0) &&
 763                             nr->nr_lastnet == htons(0xFFFE)) {
 764                                 sa->sat_addr.s_net = atif->address.s_net;
 765                                 atrtr_create(&rtdef, dev);
 766                                 atrtr_set_default(dev);
 767                         } else {
 768                                 limit = ntohs(nr->nr_lastnet);
 769                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 770                                         printk(KERN_WARNING "Too many routes/"
 771                                                             "iface.\n");
 772                                         return -EINVAL;
 773                                 }
 774                                 if (add_route)
 775                                         for (ct = ntohs(nr->nr_firstnet);
 776                                              ct <= limit; ct++) {
 777                                                 sa->sat_addr.s_net = htons(ct);
 778                                                 atrtr_create(&rtdef, dev);
 779                                         }
 780                         }
 781                         dev_mc_add(dev, aarp_mcast, 6, 1);
 782                         return 0;
 783
 784                 case SIOCGIFADDR:
 785                         if (!atif)
 786                                 return -EADDRNOTAVAIL;
 787
 788                         sa->sat_family = AF_APPLETALK;
 789                         sa->sat_addr = atif->address;
 790                         break;
 791
 792                 case SIOCGIFBRDADDR:
 793                         if (!atif)
 794                                 return -EADDRNOTAVAIL;
 795
 796                         sa->sat_family = AF_APPLETALK;
 797                         sa->sat_addr.s_net = atif->address.s_net;
 798                         sa->sat_addr.s_node = ATADDR_BCAST;
 799                         break;
 800
 801                 case SIOCATALKDIFADDR:
 802                 case SIOCDIFADDR:
 803                         if (!capable(CAP_NET_ADMIN))
 804                                 return -EPERM;
 805                         if (sa->sat_family != AF_APPLETALK)
 806                                 return -EINVAL;
 807                         atalk_dev_down(dev);
 808                         break;
 809
 810                 case SIOCSARP:
 811                         if (!capable(CAP_NET_ADMIN))
 812                                 return -EPERM;
 813                         if (sa->sat_family != AF_APPLETALK)
 814                                 return -EINVAL;
 815                         if (!atif)
 816                                 return -EADDRNOTAVAIL;
 817
 818                         /*
 819                          * for now, we only support proxy AARP on ELAP;
 820                          * we should be able to do it for LocalTalk, too.
 821                          */
 822                         if (dev->type != ARPHRD_ETHER)
 823                                 return -EPROTONOSUPPORT;
 824
 825                         /*
 826                          * atif points to the current interface on this network;
 827                          * we aren't concerned about its current status (at
 828                          * least for now), but it has all the settings about
 829                          * the network we're going to probe. Consequently, it
 830                          * must exist.
 831                          */
 832                         if (!atif)
 833                                 return -EADDRNOTAVAIL;
 834
 835                         nr = (struct atalk_netrange *)&(atif->nets);
 836                         /*
 837                          * Phase 1 is fine on Localtalk but we don't do
 838                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 839                          */
 840                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 841                                 return -EPROTONOSUPPORT;
 842
 843                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 844                             sa->sat_addr.s_node == 254)
 845                                 return -EINVAL;
 846
 847                         /*
 848                          * Check if the chosen address is used. If so we
 849                          * error and ATCP will try another.
 850                          */
 851                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 852                                 return -EADDRINUSE;
 853
 854                         /*
 855                          * We now have an address on the local network, and
 856                          * the AARP code will defend it for us until we take it
 857                          * down. We don't set up any routes right now, because
 858                          * ATCP will install them manually via SIOCADDRT.
 859                          */
 860                         break;
 861
 862                 case SIOCDARP:
 863                         if (!capable(CAP_NET_ADMIN))
 864                                 return -EPERM;
 865                         if (sa->sat_family != AF_APPLETALK)
 866                                 return -EINVAL;
 867                         if (!atif)
 868                                 return -EADDRNOTAVAIL;
 869
 870                         /* give to aarp module to remove proxy entry */
 871                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 872                         return 0;
 873         }
 874
 875         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 876 }
 877
 878 /* Routing ioctl() calls */
 879 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 880 {
 881         struct rtentry rt;
 882
 883         if (copy_from_user(&rt, arg, sizeof(rt)))
 884                 return -EFAULT;
 885
 886         switch (cmd) {
 887                 case SIOCDELRT:
 888                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 889                                 return -EINVAL;
 890                         return atrtr_delete(&((struct sockaddr_at *)
 891                                                 &rt.rt_dst)->sat_addr);
 892
 893                 case SIOCADDRT: {
 894                         struct net_device *dev = NULL;
 895                         if (rt.rt_dev) {
 896                                 char name[IFNAMSIZ];
 897                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 898                                         return -EFAULT;
 899                                 name[IFNAMSIZ-1] = '\0';
 900                                 dev = __dev_get_by_name(name);
 901                                 if (!dev)
 902                                         return -ENODEV;
 903                         }
 904                         return atrtr_create(&rt, dev);
 905                 }
 906         }
 907         return -EINVAL;
 908 }
 909
 910 /**************************************************************************\
 911 *                                                                          *
 912 * Handling for system calls applied via the various interfaces to an       *
 913 * AppleTalk socket object.                                                 *
 914 *                                                                          *
 915 \**************************************************************************/
 916
 917 /*
 918  * Checksum: This is 'optional'. It's quite likely also a good
 919  * candidate for assembler hackery 8)
 920  */
 921 static unsigned long atalk_sum_partial(const unsigned char *data,
 922                                        int len, unsigned long sum)
 923 {
 924         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 925         while (len--) {
 926                 sum += *data;
 927                 sum <<= 1;
 928                 if (sum & 0x10000) {
 929                         sum++;
 930                         sum &= 0xffff;
 931                 }
 932                 data++;
 933         }
 934         return sum;
 935 }
 936
 937 /*  Checksum skb data --  similar to skb_checksum  */
 938 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 939                                    int len, unsigned long sum)
 940 {
 941         int start = skb_headlen(skb);
 942         int i, copy;
 943
 944         /* checksum stuff in header space */
 945         if ( (copy = start - offset) > 0) {
 946                 if (copy > len)
 947                         copy = len;
 948                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 949                 if ( (len -= copy) == 0)
 950                         return sum;
 951
 952                 offset += copy;
 953         }
 954
 955         /* checksum stuff in frags */
 956         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 957                 int end;
 958
 959                 BUG_TRAP(start <= offset + len);
 960
 961                 end = start + skb_shinfo(skb)->frags[i].size;
 962                 if ((copy = end - offset) > 0) {
 963                         u8 *vaddr;
 964                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 965
 966                         if (copy > len)
 967                                 copy = len;
 968                         vaddr = kmap_skb_frag(frag);
 969                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 970                                                   offset - start, copy, sum);
 971                         kunmap_skb_frag(vaddr);
 972
 973                         if (!(len -= copy))
 974                                 return sum;
 975                         offset += copy;
 976                 }
 977                 start = end;
 978         }
 979
 980         if (skb_shinfo(skb)->frag_list) {
 981                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
 982
 983                 for (; list; list = list->next) {
 984                         int end;
 985
 986                         BUG_TRAP(start <= offset + len);
 987
 988                         end = start + list->len;
 989                         if ((copy = end - offset) > 0) {
 990                                 if (copy > len)
 991                                         copy = len;
 992                                 sum = atalk_sum_skb(list, offset - start,
 993                                                     copy, sum);
 994                                 if ((len -= copy) == 0)
 995                                         return sum;
 996                                 offset += copy;
 997                         }
 998                         start = end;
 999                 }
1000         }
1001
1002         BUG_ON(len > 0);
1003
1004         return sum;
1005 }
1006
1007 static unsigned short atalk_checksum(const struct sk_buff *skb, int len)
1008 {
1009         unsigned long sum;
1010
1011         /* skip header 4 bytes */
1012         sum = atalk_sum_skb(skb, 4, len-4, 0);
1013
1014         /* Use 0xFFFF for 0. 0 itself means none */
1015         return sum ? htons((unsigned short)sum) : 0xFFFF;
1016 }
1017
1018 static struct proto ddp_proto = {
1019         .name     = "DDP",
1020         .owner    = THIS_MODULE,
1021         .obj_size = sizeof(struct atalk_sock),
1022 };
1023
1024 /*
1025  * Create a socket. Initialise the socket, blank the addresses
1026  * set the state.
1027  */
1028 static int atalk_create(struct socket *sock, int protocol)
1029 {
1030         struct sock *sk;
1031         int rc = -ESOCKTNOSUPPORT;
1032
1033         /*
1034          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1035          * and gives you the full ELAP frame. Should be handy for CAP 8)
1036          */
1037         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1038                 goto out;
1039         rc = -ENOMEM;
1040         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1041         if (!sk)
1042                 goto out;
1043         rc = 0;
1044         sock->ops = &atalk_dgram_ops;
1045         sock_init_data(sock, sk);
1046
1047         /* Checksums on by default */
1048         sock_set_flag(sk, SOCK_ZAPPED);
1049 out:
1050         return rc;
1051 }
1052
1053 /* Free a socket. No work needed */
1054 static int atalk_release(struct socket *sock)
1055 {
1056         struct sock *sk = sock->sk;
1057
1058         if (sk) {
1059                 sock_orphan(sk);
1060                 sock->sk = NULL;
1061                 atalk_destroy_socket(sk);
1062         }
1063         return 0;
1064 }
1065
1066 /**
1067  * atalk_pick_and_bind_port - Pick a source port when one is not given
1068  * @sk - socket to insert into the tables
1069  * @sat - address to search for
1070  *
1071  * Pick a source port when one is not given. If we can find a suitable free
1072  * one, we insert the socket into the tables using it.
1073  *
1074  * This whole operation must be atomic.
1075  */
1076 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1077 {
1078         int retval;
1079
1080         write_lock_bh(&atalk_sockets_lock);
1081
1082         for (sat->sat_port = ATPORT_RESERVED;
1083              sat->sat_port < ATPORT_LAST;
1084              sat->sat_port++) {
1085                 struct sock *s;
1086                 struct hlist_node *node;
1087
1088                 sk_for_each(s, node, &atalk_sockets) {
1089                         struct atalk_sock *at = at_sk(s);
1090
1091                         if (at->src_net == sat->sat_addr.s_net &&
1092                             at->src_node == sat->sat_addr.s_node &&
1093                             at->src_port == sat->sat_port)
1094                                 goto try_next_port;
1095                 }
1096
1097                 /* Wheee, it's free, assign and insert. */
1098                 __atalk_insert_socket(sk);
1099                 at_sk(sk)->src_port = sat->sat_port;
1100                 retval = 0;
1101                 goto out;
1102
1103 try_next_port:;
1104         }
1105
1106         retval = -EBUSY;
1107 out:
1108         write_unlock_bh(&atalk_sockets_lock);
1109         return retval;
1110 }
1111
1112 static int atalk_autobind(struct sock *sk)
1113 {
1114         struct atalk_sock *at = at_sk(sk);
1115         struct sockaddr_at sat;
1116         struct atalk_addr *ap = atalk_find_primary();
1117         int n = -EADDRNOTAVAIL;
1118
1119         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1120                 goto out;
1121
1122         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1123         at->src_node = sat.sat_addr.s_node = ap->s_node;
1124
1125         n = atalk_pick_and_bind_port(sk, &sat);
1126         if (!n)
1127                 sock_reset_flag(sk, SOCK_ZAPPED);
1128 out:
1129         return n;
1130 }
1131
1132 /* Set the address 'our end' of the connection */
1133 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1134 {
1135         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1136         struct sock *sk = sock->sk;
1137         struct atalk_sock *at = at_sk(sk);
1138
1139         if (!sock_flag(sk, SOCK_ZAPPED) ||
1140             addr_len != sizeof(struct sockaddr_at))
1141                 return -EINVAL;
1142
1143         if (addr->sat_family != AF_APPLETALK)
1144                 return -EAFNOSUPPORT;
1145
1146         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1147                 struct atalk_addr *ap = atalk_find_primary();
1148
1149                 if (!ap)
1150                         return -EADDRNOTAVAIL;
1151
1152                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1153                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1154         } else {
1155                 if (!atalk_find_interface(addr->sat_addr.s_net,
1156                                           addr->sat_addr.s_node))
1157                         return -EADDRNOTAVAIL;
1158
1159                 at->src_net  = addr->sat_addr.s_net;
1160                 at->src_node = addr->sat_addr.s_node;
1161         }
1162
1163         if (addr->sat_port == ATADDR_ANYPORT) {
1164                 int n = atalk_pick_and_bind_port(sk, addr);
1165
1166                 if (n < 0)
1167                         return n;
1168         } else {
1169                 at->src_port = addr->sat_port;
1170
1171                 if (atalk_find_or_insert_socket(sk, addr))
1172                         return -EADDRINUSE;
1173         }
1174
1175         sock_reset_flag(sk, SOCK_ZAPPED);
1176         return 0;
1177 }
1178
1179 /* Set the address we talk to */
1180 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1181                          int addr_len, int flags)
1182 {
1183         struct sock *sk = sock->sk;
1184         struct atalk_sock *at = at_sk(sk);
1185         struct sockaddr_at *addr;
1186
1187         sk->sk_state   = TCP_CLOSE;
1188         sock->state = SS_UNCONNECTED;
1189
1190         if (addr_len != sizeof(*addr))
1191                 return -EINVAL;
1192
1193         addr = (struct sockaddr_at *)uaddr;
1194
1195         if (addr->sat_family != AF_APPLETALK)
1196                 return -EAFNOSUPPORT;
1197
1198         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1199             !sock_flag(sk, SOCK_BROADCAST)) {
1200 #if 1
1201                 printk(KERN_WARNING "%s is broken and did not set "
1202                                     "SO_BROADCAST. It will break when 2.2 is "
1203                                     "released.\n",
1204                         current->comm);
1205 #else
1206                 return -EACCES;
1207 #endif
1208         }
1209
1210         if (sock_flag(sk, SOCK_ZAPPED))
1211                 if (atalk_autobind(sk) < 0)
1212                         return -EBUSY;
1213
1214         if (!atrtr_get_dev(&addr->sat_addr))
1215                 return -ENETUNREACH;
1216
1217         at->dest_port = addr->sat_port;
1218         at->dest_net  = addr->sat_addr.s_net;
1219         at->dest_node = addr->sat_addr.s_node;
1220
1221         sock->state  = SS_CONNECTED;
1222         sk->sk_state = TCP_ESTABLISHED;
1223         return 0;
1224 }
1225
1226 /*
1227  * Find the name of an AppleTalk socket. Just copy the right
1228  * fields into the sockaddr.
1229  */
1230 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1231                          int *uaddr_len, int peer)
1232 {
1233         struct sockaddr_at sat;
1234         struct sock *sk = sock->sk;
1235         struct atalk_sock *at = at_sk(sk);
1236
1237         if (sock_flag(sk, SOCK_ZAPPED))
1238                 if (atalk_autobind(sk) < 0)
1239                         return -ENOBUFS;
1240
1241         *uaddr_len = sizeof(struct sockaddr_at);
1242
1243         if (peer) {
1244                 if (sk->sk_state != TCP_ESTABLISHED)
1245                         return -ENOTCONN;
1246
1247                 sat.sat_addr.s_net  = at->dest_net;
1248                 sat.sat_addr.s_node = at->dest_node;
1249                 sat.sat_port        = at->dest_port;
1250         } else {
1251                 sat.sat_addr.s_net  = at->src_net;
1252                 sat.sat_addr.s_node = at->src_node;
1253                 sat.sat_port        = at->src_port;
1254         }
1255
1256         sat.sat_family = AF_APPLETALK;
1257         memcpy(uaddr, &sat, sizeof(sat));
1258         return 0;
1259 }
1260
1261 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1262 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1263 {
1264         return skb->data[12] == 22;
1265 }
1266
1267 static int handle_ip_over_ddp(struct sk_buff *skb)
1268 {
1269         struct net_device *dev = __dev_get_by_name("ipddp0");
1270         struct net_device_stats *stats;
1271
1272         /* This needs to be able to handle ipddp"N" devices */
1273         if (!dev)
1274                 return -ENODEV;
1275
1276         skb->protocol = htons(ETH_P_IP);
1277         skb_pull(skb, 13);
1278         skb->dev   = dev;
1279         skb->h.raw = skb->data;
1280
1281         stats = dev->priv;
1282         stats->rx_packets++;
1283         stats->rx_bytes += skb->len + 13;
1284         netif_rx(skb);  /* Send the SKB up to a higher place. */
1285         return 0;
1286 }
1287 #else
1288 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1289 #define is_ip_over_ddp(skb) 0
1290 #define handle_ip_over_ddp(skb) 0
1291 #endif
1292
1293 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1294                                struct ddpehdr *ddp, struct ddpebits *ddphv,
1295                                int origlen)
1296 {
1297         struct atalk_route *rt;
1298         struct atalk_addr ta;
1299
1300         /*
1301          * Don't route multicast, etc., packets, or packets sent to "this
1302          * network"
1303          */
1304         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1305                 /*
1306                  * FIXME:
1307                  *
1308                  * Can it ever happen that a packet is from a PPP iface and
1309                  * needs to be broadcast onto the default network?
1310                  */
1311                 if (dev->type == ARPHRD_PPP)
1312                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1313                                           "packet received from PPP iface\n");
1314                 goto free_it;
1315         }
1316
1317         ta.s_net  = ddp->deh_dnet;
1318         ta.s_node = ddp->deh_dnode;
1319
1320         /* Route the packet */
1321         rt = atrtr_find(&ta);
1322         if (!rt || ddphv->deh_hops == DDP_MAXHOPS)
1323                 goto free_it;
1324         /* FIXME: use skb->cb to be able to use shared skbs */
1325         ddphv->deh_hops++;
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 + ddphv->deh_len)));
1341
1342         /* Mend the byte order */
1343         /* FIXME: use skb->cb to be able to use shared skbs */
1344         *((__u16 *)ddp) = ntohs(*((__u16 *)ddphv));
1345
1346         /*
1347          * Send the buffer onwards
1348          *
1349          * Now we must always be careful. If it's come from LocalTalk to
1350          * EtherTalk it might not fit
1351          *
1352          * Order matters here: If a packet has to be copied to make a new
1353          * headroom (rare hopefully) then it won't need unsharing.
1354          *
1355          * Note. ddp-> becomes invalid at the realloc.
1356          */
1357         if (skb_headroom(skb) < 22) {
1358                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1359                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1360                 kfree_skb(skb);
1361                 if (!nskb)
1362                         goto out;
1363                 skb = nskb;
1364         } else
1365                 skb = skb_unshare(skb, GFP_ATOMIC);
1366
1367         /*
1368          * If the buffer didn't vanish into the lack of space bitbucket we can
1369          * send it.
1370          */
1371         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1372                 goto free_it;
1373 out:
1374         return;
1375 free_it:
1376         kfree_skb(skb);
1377 }
1378
1379 /**
1380  *      atalk_rcv - Receive a packet (in skb) from device dev
1381  *      @skb - packet received
1382  *      @dev - network device where the packet comes from
1383  *      @pt - packet type
1384  *
1385  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1386  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1387  *      header, skb->len is the DDP length. The physical headers have been
1388  *      extracted. PPP should probably pass frames marked as for this layer.
1389  *      [ie ARPHRD_ETHERTALK]
1390  */
1391 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1392                      struct packet_type *pt)
1393 {
1394         struct ddpehdr *ddp;
1395         struct sock *sock;
1396         struct atalk_iface *atif;
1397         struct sockaddr_at tosat;
1398         int origlen;
1399         struct ddpebits ddphv;
1400
1401         /* Don't mangle buffer if shared */
1402         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1403                 goto out;
1404
1405         /* Size check and make sure header is contiguous */
1406         if (!pskb_may_pull(skb, sizeof(*ddp)))
1407                 goto freeit;
1408
1409         ddp = ddp_hdr(skb);
1410
1411         /*
1412          *      Fix up the length field [Ok this is horrible but otherwise
1413          *      I end up with unions of bit fields and messy bit field order
1414          *      compiler/endian dependencies..]
1415          */
1416         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1417
1418         /* Trim buffer in case of stray trailing data */
1419         origlen = skb->len;
1420         skb_trim(skb, min_t(unsigned int, skb->len, ddphv.deh_len));
1421
1422         /*
1423          * Size check to see if ddp->deh_len was crap
1424          * (Otherwise we'll detonate most spectacularly
1425          * in the middle of recvmsg()).
1426          */
1427         if (skb->len < sizeof(*ddp))
1428                 goto freeit;
1429
1430         /*
1431          * Any checksums. Note we don't do htons() on this == is assumed to be
1432          * valid for net byte orders all over the networking code...
1433          */
1434         if (ddp->deh_sum &&
1435             atalk_checksum(skb, ddphv.deh_len) != ddp->deh_sum)
1436                 /* Not a valid AppleTalk frame - dustbin time */
1437                 goto freeit;
1438
1439         /* Check the packet is aimed at us */
1440         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1441                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1442         else
1443                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1444
1445         /* Not ours, so we route the packet via the correct AppleTalk iface */
1446         if (!atif) {
1447                 atalk_route_packet(skb, dev, ddp, &ddphv, origlen);
1448                 goto out;
1449         }
1450
1451         /* if IP over DDP is not selected this code will be optimized out */
1452         if (is_ip_over_ddp(skb))
1453                 return handle_ip_over_ddp(skb);
1454         /*
1455          * Which socket - atalk_search_socket() looks for a *full match*
1456          * of the <net, node, port> tuple.
1457          */
1458         tosat.sat_addr.s_net  = ddp->deh_dnet;
1459         tosat.sat_addr.s_node = ddp->deh_dnode;
1460         tosat.sat_port        = ddp->deh_dport;
1461
1462         sock = atalk_search_socket(&tosat, atif);
1463         if (!sock) /* But not one of our sockets */
1464                 goto freeit;
1465
1466         /* Queue packet (standard) */
1467         skb->sk = sock;
1468
1469         if (sock_queue_rcv_skb(sock, skb) < 0)
1470                 goto freeit;
1471 out:
1472         return 0;
1473 freeit:
1474         kfree_skb(skb);
1475         goto out;
1476 }
1477
1478 /*
1479  * Receive a LocalTalk frame. We make some demands on the caller here.
1480  * Caller must provide enough headroom on the packet to pull the short
1481  * header and append a long one.
1482  */
1483 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1484                         struct packet_type *pt)
1485 {
1486         /* Expand any short form frames */
1487         if (skb->mac.raw[2] == 1) {
1488                 struct ddpehdr *ddp;
1489                 /* Find our address */
1490                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1491
1492                 if (!ap || skb->len < sizeof(struct ddpshdr))
1493                         goto freeit;
1494
1495                 /* Don't mangle buffer if shared */
1496                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1497                         return 0;
1498
1499                 /*
1500                  * The push leaves us with a ddephdr not an shdr, and
1501                  * handily the port bytes in the right place preset.
1502                  */
1503                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1504
1505                 /* Now fill in the long header */
1506
1507                 /*
1508                  * These two first. The mac overlays the new source/dest
1509                  * network information so we MUST copy these before
1510                  * we write the network numbers !
1511                  */
1512
1513                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1514                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1515
1516                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1517                 ddp->deh_snet  = ap->s_net;
1518                 ddp->deh_sum   = 0;             /* No checksum */
1519                 /*
1520                  * Not sure about this bit...
1521                  */
1522                 ddp->deh_len   = skb->len;
1523                 ddp->deh_hops  = DDP_MAXHOPS;   /* Non routable, so force a drop
1524                                                    if we slip up later */
1525                 /* Mend the byte order */
1526                 *((__u16 *)ddp) = htons(*((__u16 *)ddp));
1527         }
1528         skb->h.raw = skb->data;
1529
1530         return atalk_rcv(skb, dev, pt);
1531 freeit:
1532         kfree_skb(skb);
1533         return 0;
1534 }
1535
1536 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1537                          size_t len)
1538 {
1539         struct sock *sk = sock->sk;
1540         struct atalk_sock *at = at_sk(sk);
1541         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1542         int flags = msg->msg_flags;
1543         int loopback = 0;
1544         struct sockaddr_at local_satalk, gsat;
1545         struct sk_buff *skb;
1546         struct net_device *dev;
1547         struct ddpehdr *ddp;
1548         int size;
1549         struct atalk_route *rt;
1550         int err;
1551
1552         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1553                 return -EINVAL;
1554
1555         if (len > DDP_MAXSZ)
1556                 return -EMSGSIZE;
1557
1558         if (usat) {
1559                 if (sock_flag(sk, SOCK_ZAPPED))
1560                         if (atalk_autobind(sk) < 0)
1561                                 return -EBUSY;
1562
1563                 if (msg->msg_namelen < sizeof(*usat) ||
1564                     usat->sat_family != AF_APPLETALK)
1565                         return -EINVAL;
1566
1567                 /* netatalk doesn't implement this check */
1568                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1569                     !sock_flag(sk, SOCK_BROADCAST)) {
1570                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1571                                          "it will break before 2.2\n");
1572 #if 0
1573                         return -EPERM;
1574 #endif
1575                 }
1576         } else {
1577                 if (sk->sk_state != TCP_ESTABLISHED)
1578                         return -ENOTCONN;
1579                 usat = &local_satalk;
1580                 usat->sat_family      = AF_APPLETALK;
1581                 usat->sat_port        = at->dest_port;
1582                 usat->sat_addr.s_node = at->dest_node;
1583                 usat->sat_addr.s_net  = at->dest_net;
1584         }
1585
1586         /* Build a packet */
1587         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1588
1589         /* For headers */
1590         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1591
1592         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1593                 rt = atrtr_find(&usat->sat_addr);
1594                 if (!rt)
1595                         return -ENETUNREACH;
1596
1597                 dev = rt->dev;
1598         } else {
1599                 struct atalk_addr at_hint;
1600
1601                 at_hint.s_node = 0;
1602                 at_hint.s_net  = at->src_net;
1603
1604                 rt = atrtr_find(&at_hint);
1605                 if (!rt)
1606                         return -ENETUNREACH;
1607
1608                 dev = rt->dev;
1609         }
1610
1611         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1612                         sk, size, dev->name);
1613
1614         size += dev->hard_header_len;
1615         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1616         if (!skb)
1617                 return err;
1618
1619         skb->sk = sk;
1620         skb_reserve(skb, ddp_dl->header_length);
1621         skb_reserve(skb, dev->hard_header_len);
1622         skb->dev = dev;
1623
1624         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1625
1626         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1627         ddp->deh_pad  = 0;
1628         ddp->deh_hops = 0;
1629         ddp->deh_len  = len + sizeof(*ddp);
1630         /*
1631          * Fix up the length field [Ok this is horrible but otherwise
1632          * I end up with unions of bit fields and messy bit field order
1633          * compiler/endian dependencies..
1634          */
1635         *((__u16 *)ddp) = ntohs(*((__u16 *)ddp));
1636
1637         ddp->deh_dnet  = usat->sat_addr.s_net;
1638         ddp->deh_snet  = at->src_net;
1639         ddp->deh_dnode = usat->sat_addr.s_node;
1640         ddp->deh_snode = at->src_node;
1641         ddp->deh_dport = usat->sat_port;
1642         ddp->deh_sport = at->src_port;
1643
1644         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1645
1646         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1647         if (err) {
1648                 kfree_skb(skb);
1649                 return -EFAULT;
1650         }
1651
1652         if (sk->sk_no_check == 1)
1653                 ddp->deh_sum = 0;
1654         else
1655                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1656
1657         /*
1658          * Loopback broadcast packets to non gateway targets (ie routes
1659          * to group we are in)
1660          */
1661         if (ddp->deh_dnode == ATADDR_BCAST &&
1662             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1663                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1664
1665                 if (skb2) {
1666                         loopback = 1;
1667                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1668                         if (aarp_send_ddp(dev, skb2,
1669                                           &usat->sat_addr, NULL) == -1)
1670                                 kfree_skb(skb2);
1671                                 /* else queued/sent above in the aarp queue */
1672                 }
1673         }
1674
1675         if (dev->flags & IFF_LOOPBACK || loopback) {
1676                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1677                 /* loop back */
1678                 skb_orphan(skb);
1679                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1680         } else {
1681                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1682                 if (rt->flags & RTF_GATEWAY) {
1683                     gsat.sat_addr = rt->gateway;
1684                     usat = &gsat;
1685                 }
1686
1687                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1688                         kfree_skb(skb);
1689                 /* else queued/sent above in the aarp queue */
1690         }
1691         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1692
1693         return len;
1694 }
1695
1696 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1697                          size_t size, int flags)
1698 {
1699         struct sock *sk = sock->sk;
1700         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1701         struct ddpehdr *ddp;
1702         int copied = 0;
1703         int err = 0;
1704         struct ddpebits ddphv;
1705         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1706                                                 flags & MSG_DONTWAIT, &err);
1707         if (!skb)
1708                 return err;
1709
1710         /* FIXME: use skb->cb to be able to use shared skbs */
1711         ddp = ddp_hdr(skb);
1712         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1713
1714         if (sk->sk_type == SOCK_RAW) {
1715                 copied = ddphv.deh_len;
1716                 if (copied > size) {
1717                         copied = size;
1718                         msg->msg_flags |= MSG_TRUNC;
1719                 }
1720
1721                 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1722         } else {
1723                 copied = ddphv.deh_len - sizeof(*ddp);
1724                 if (copied > size) {
1725                         copied = size;
1726                         msg->msg_flags |= MSG_TRUNC;
1727                 }
1728                 err = skb_copy_datagram_iovec(skb, sizeof(*ddp),
1729                                               msg->msg_iov, copied);
1730         }
1731
1732         if (!err) {
1733                 if (sat) {
1734                         sat->sat_family      = AF_APPLETALK;
1735                         sat->sat_port        = ddp->deh_sport;
1736                         sat->sat_addr.s_node = ddp->deh_snode;
1737                         sat->sat_addr.s_net  = ddp->deh_snet;
1738                 }
1739                 msg->msg_namelen = sizeof(*sat);
1740         }
1741
1742         skb_free_datagram(sk, skb);     /* Free the datagram. */
1743         return err ? : copied;
1744 }
1745
1746
1747 /*
1748  * AppleTalk ioctl calls.
1749  */
1750 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1751 {
1752         int rc = -EINVAL;
1753         struct sock *sk = sock->sk;
1754         void __user *argp = (void __user *)arg;
1755
1756         switch (cmd) {
1757                 /* Protocol layer */
1758                 case TIOCOUTQ: {
1759                         long amount = sk->sk_sndbuf -
1760                                       atomic_read(&sk->sk_wmem_alloc);
1761
1762                         if (amount < 0)
1763                                 amount = 0;
1764                         rc = put_user(amount, (int __user *)argp);
1765                         break;
1766                 }
1767                 case TIOCINQ: {
1768                         /*
1769                          * These two are safe on a single CPU system as only
1770                          * user tasks fiddle here
1771                          */
1772                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1773                         long amount = 0;
1774
1775                         if (skb)
1776                                 amount = skb->len - sizeof(struct ddpehdr);
1777                         rc = put_user(amount, (int __user *)argp);
1778                         break;
1779                 }
1780                 case SIOCGSTAMP:
1781                         rc = sock_get_timestamp(sk, argp);
1782                         break;
1783                 /* Routing */
1784                 case SIOCADDRT:
1785                 case SIOCDELRT:
1786                         rc = -EPERM;
1787                         if (capable(CAP_NET_ADMIN))
1788                                 rc = atrtr_ioctl(cmd, argp);
1789                         break;
1790                 /* Interface */
1791                 case SIOCGIFADDR:
1792                 case SIOCSIFADDR:
1793                 case SIOCGIFBRDADDR:
1794                 case SIOCATALKDIFADDR:
1795                 case SIOCDIFADDR:
1796                 case SIOCSARP:          /* proxy AARP */
1797                 case SIOCDARP:          /* proxy AARP */
1798                         rtnl_lock();
1799                         rc = atif_ioctl(cmd, argp);
1800                         rtnl_unlock();
1801                         break;
1802                 /* Physical layer ioctl calls */
1803                 case SIOCSIFLINK:
1804                 case SIOCGIFHWADDR:
1805                 case SIOCSIFHWADDR:
1806                 case SIOCGIFFLAGS:
1807                 case SIOCSIFFLAGS:
1808                 case SIOCGIFTXQLEN:
1809                 case SIOCSIFTXQLEN:
1810                 case SIOCGIFMTU:
1811                 case SIOCGIFCONF:
1812                 case SIOCADDMULTI:
1813                 case SIOCDELMULTI:
1814                 case SIOCGIFCOUNT:
1815                 case SIOCGIFINDEX:
1816                 case SIOCGIFNAME:
1817                         rc = dev_ioctl(cmd, argp);
1818                         break;
1819         }
1820
1821         return rc;
1822 }
1823
1824 static struct net_proto_family atalk_family_ops = {
1825         .family         = PF_APPLETALK,
1826         .create         = atalk_create,
1827         .owner          = THIS_MODULE,
1828 };
1829
1830 static struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1831         .family         = PF_APPLETALK,
1832         .owner          = THIS_MODULE,
1833         .release        = atalk_release,
1834         .bind           = atalk_bind,
1835         .connect        = atalk_connect,
1836         .socketpair     = sock_no_socketpair,
1837         .accept         = sock_no_accept,
1838         .getname        = atalk_getname,
1839         .poll           = datagram_poll,
1840         .ioctl          = atalk_ioctl,
1841         .listen         = sock_no_listen,
1842         .shutdown       = sock_no_shutdown,
1843         .setsockopt     = sock_no_setsockopt,
1844         .getsockopt     = sock_no_getsockopt,
1845         .sendmsg        = atalk_sendmsg,
1846         .recvmsg        = atalk_recvmsg,
1847         .mmap           = sock_no_mmap,
1848         .sendpage       = sock_no_sendpage,
1849 };
1850
1851 #include <linux/smp_lock.h>
1852 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1853
1854 static struct notifier_block ddp_notifier = {
1855         .notifier_call  = ddp_device_event,
1856 };
1857
1858 static struct packet_type ltalk_packet_type = {
1859         .type           = __constant_htons(ETH_P_LOCALTALK),
1860         .func           = ltalk_rcv,
1861 };
1862
1863 static struct packet_type ppptalk_packet_type = {
1864         .type           = __constant_htons(ETH_P_PPPTALK),
1865         .func           = atalk_rcv,
1866 };
1867
1868 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1869
1870 /* Export symbols for use by drivers when AppleTalk is a module */
1871 EXPORT_SYMBOL(aarp_send_ddp);
1872 EXPORT_SYMBOL(atrtr_get_dev);
1873 EXPORT_SYMBOL(atalk_find_dev_addr);
1874
1875 static char atalk_err_snap[] __initdata =
1876         KERN_CRIT "Unable to register DDP with SNAP.\n";
1877
1878 /* Called by proto.c on kernel start up */
1879 static int __init atalk_init(void)
1880 {
1881         int rc = proto_register(&ddp_proto, 0);
1882
1883         if (rc != 0)
1884                 goto out;
1885
1886         (void)sock_register(&atalk_family_ops);
1887         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1888         if (!ddp_dl)
1889                 printk(atalk_err_snap);
1890
1891         dev_add_pack(&ltalk_packet_type);
1892         dev_add_pack(&ppptalk_packet_type);
1893
1894         register_netdevice_notifier(&ddp_notifier);
1895         aarp_proto_init();
1896         atalk_proc_init();
1897         atalk_register_sysctl();
1898 out:
1899         return rc;
1900 }
1901 module_init(atalk_init);
1902
1903 /*
1904  * No explicit module reference count manipulation is needed in the
1905  * protocol. Socket layer sets module reference count for us
1906  * and interfaces reference counting is done
1907  * by the network device layer.
1908  *
1909  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1910  * sockets be closed from user space.
1911  */
1912 static void __exit atalk_exit(void)
1913 {
1914 #ifdef CONFIG_SYSCTL
1915         atalk_unregister_sysctl();
1916 #endif /* CONFIG_SYSCTL */
1917         atalk_proc_exit();
1918         aarp_cleanup_module();  /* General aarp clean-up. */
1919         unregister_netdevice_notifier(&ddp_notifier);
1920         dev_remove_pack(&ltalk_packet_type);
1921         dev_remove_pack(&ppptalk_packet_type);
1922         unregister_snap_client(ddp_dl);
1923         sock_unregister(PF_APPLETALK);
1924         proto_unregister(&ddp_proto);
1925 }
1926 module_exit(atalk_exit);
1927
1928 MODULE_LICENSE("GPL");
1929 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1930 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1931 MODULE_ALIAS_NETPROTO(PF_APPLETALK);