net/appletalk/ddp.c

   1 /*
   2  *      DDP:    An implementation of the AppleTalk DDP protocol for
   3  *              Ethernet 'ELAP'.
   4  *
   5  *              Alan Cox  <Alan.Cox@linux.org>
   6  *
   7  *              With more than a little assistance from
   8  *
   9  *              Wesley Craig <netatalk@umich.edu>
  10  *
  11  *      Fixes:
  12  *              Neil Horman             :       Added missing device ioctls
  13  *              Michael Callahan        :       Made routing work
  14  *              Wesley Craig            :       Fix probing to listen to a
  15  *                                              passed node id.
  16  *              Alan Cox                :       Added send/recvmsg support
  17  *              Alan Cox                :       Moved at. to protinfo in
  18  *                                              socket.
  19  *              Alan Cox                :       Added firewall hooks.
  20  *              Alan Cox                :       Supports new ARPHRD_LOOPBACK
  21  *              Christer Weinigel       :       Routing and /proc fixes.
  22  *              Bradford Johnson        :       LocalTalk.
  23  *              Tom Dyas                :       Module support.
  24  *              Alan Cox                :       Hooks for PPP (based on the
  25  *                                              LocalTalk hook).
  26  *              Alan Cox                :       Posix bits
  27  *              Alan Cox/Mike Freeman   :       Possible fix to NBP problems
  28  *              Bradford Johnson        :       IP-over-DDP (experimental)
  29  *              Jay Schulist            :       Moved IP-over-DDP to its own
  30  *                                              driver file. (ipddp.c & ipddp.h)
  31  *              Jay Schulist            :       Made work as module with
  32  *                                              AppleTalk drivers, cleaned it.
  33  *              Rob Newberry            :       Added proxy AARP and AARP
  34  *                                              procfs, moved probing to AARP
  35  *                                              module.
  36  *              Adrian Sun/
  37  *              Michael Zuelsdorff      :       fix for net.0 packets. don't
  38  *                                              allow illegal ether/tokentalk
  39  *                                              port assignment. we lose a
  40  *                                              valid localtalk port as a
  41  *                                              result.
  42  *              Arnaldo C. de Melo      :       Cleanup, in preparation for
  43  *                                              shared skb support 8)
  44  *              Arnaldo C. de Melo      :       Move proc stuff to atalk_proc.c,
  45  *                                              use seq_file
  46  *
  47  *              This program is free software; you can redistribute it and/or
  48  *              modify it under the terms of the GNU General Public License
  49  *              as published by the Free Software Foundation; either version
  50  *              2 of the License, or (at your option) any later version.
  51  *
  52  */
  53
  54 #include <linux/capability.h>
  55 #include <linux/module.h>
  56 #include <linux/if_arp.h>
  57 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
  58 #include <net/datalink.h>
  59 #include <net/psnap.h>
  60 #include <net/sock.h>
  61 #include <net/tcp_states.h>
  62 #include <net/route.h>
  63 #include <linux/atalk.h>
  64 #include "../core/kmap_skb.h"
  65
  66 struct datalink_proto *ddp_dl, *aarp_dl;
  67 static const struct proto_ops atalk_dgram_ops;
  68
  69 /**************************************************************************\
  70 *                                                                          *
  71 * Handlers for the socket list.                                            *
  72 *                                                                          *
  73 \**************************************************************************/
  74
  75 HLIST_HEAD(atalk_sockets);
  76 DEFINE_RWLOCK(atalk_sockets_lock);
  77
  78 static inline void __atalk_insert_socket(struct sock *sk)
  79 {
  80         sk_add_node(sk, &atalk_sockets);
  81 }
  82
  83 static inline void atalk_remove_socket(struct sock *sk)
  84 {
  85         write_lock_bh(&atalk_sockets_lock);
  86         sk_del_node_init(sk);
  87         write_unlock_bh(&atalk_sockets_lock);
  88 }
  89
  90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  91                                         struct atalk_iface *atif)
  92 {
  93         struct sock *s;
  94         struct hlist_node *node;
  95
  96         read_lock_bh(&atalk_sockets_lock);
  97         sk_for_each(s, node, &atalk_sockets) {
  98                 struct atalk_sock *at = at_sk(s);
  99
 100                 if (to->sat_port != at->src_port)
 101                         continue;
 102
 103                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 104                     to->sat_addr.s_node == ATADDR_BCAST)
 105                         goto found;
 106
 107                 if (to->sat_addr.s_net == at->src_net &&
 108                     (to->sat_addr.s_node == at->src_node ||
 109                      to->sat_addr.s_node == ATADDR_BCAST ||
 110                      to->sat_addr.s_node == ATADDR_ANYNODE))
 111                         goto found;
 112
 113                 /* XXXX.0 -- we got a request for this router. make sure
 114                  * that the node is appropriately set. */
 115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 116                     to->sat_addr.s_net != ATADDR_ANYNET &&
 117                     atif->address.s_node == at->src_node) {
 118                         to->sat_addr.s_node = atif->address.s_node;
 119                         goto found;
 120                 }
 121         }
 122         s = NULL;
 123 found:
 124         read_unlock_bh(&atalk_sockets_lock);
 125         return s;
 126 }
 127
 128 /**
 129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 130  * @sk - socket to insert in the list if it is not there already
 131  * @sat - address to search for
 132  *
 133  * Try to find a socket matching ADDR in the socket list, if found then return
 134  * it. If not, insert SK into the socket list.
 135  *
 136  * This entire operation must execute atomically.
 137  */
 138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 139                                                 struct sockaddr_at *sat)
 140 {
 141         struct sock *s;
 142         struct hlist_node *node;
 143         struct atalk_sock *at;
 144
 145         write_lock_bh(&atalk_sockets_lock);
 146         sk_for_each(s, node, &atalk_sockets) {
 147                 at = at_sk(s);
 148
 149                 if (at->src_net == sat->sat_addr.s_net &&
 150                     at->src_node == sat->sat_addr.s_node &&
 151                     at->src_port == sat->sat_port)
 152                         goto found;
 153         }
 154         s = NULL;
 155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 156 found:
 157         write_unlock_bh(&atalk_sockets_lock);
 158         return s;
 159 }
 160
 161 static void atalk_destroy_timer(unsigned long data)
 162 {
 163         struct sock *sk = (struct sock *)data;
 164
 165         if (atomic_read(&sk->sk_wmem_alloc) ||
 166             atomic_read(&sk->sk_rmem_alloc)) {
 167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 168                 add_timer(&sk->sk_timer);
 169         } else
 170                 sock_put(sk);
 171 }
 172
 173 static inline void atalk_destroy_socket(struct sock *sk)
 174 {
 175         atalk_remove_socket(sk);
 176         skb_queue_purge(&sk->sk_receive_queue);
 177
 178         if (atomic_read(&sk->sk_wmem_alloc) ||
 179             atomic_read(&sk->sk_rmem_alloc)) {
 180                 init_timer(&sk->sk_timer);
 181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 182                 sk->sk_timer.function   = atalk_destroy_timer;
 183                 sk->sk_timer.data       = (unsigned long)sk;
 184                 add_timer(&sk->sk_timer);
 185         } else
 186                 sock_put(sk);
 187 }
 188
 189 /**************************************************************************\
 190 *                                                                          *
 191 * Routing tables for the AppleTalk socket layer.                           *
 192 *                                                                          *
 193 \**************************************************************************/
 194
 195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 196 struct atalk_route *atalk_routes;
 197 DEFINE_RWLOCK(atalk_routes_lock);
 198
 199 struct atalk_iface *atalk_interfaces;
 200 DEFINE_RWLOCK(atalk_interfaces_lock);
 201
 202 /* For probing devices or in a routerless network */
 203 struct atalk_route atrtr_default;
 204
 205 /* AppleTalk interface control */
 206 /*
 207  * Drop a device. Doesn't drop any of its routes - that is the caller's
 208  * problem. Called when we down the interface or delete the address.
 209  */
 210 static void atif_drop_device(struct net_device *dev)
 211 {
 212         struct atalk_iface **iface = &atalk_interfaces;
 213         struct atalk_iface *tmp;
 214
 215         write_lock_bh(&atalk_interfaces_lock);
 216         while ((tmp = *iface) != NULL) {
 217                 if (tmp->dev == dev) {
 218                         *iface = tmp->next;
 219                         dev_put(dev);
 220                         kfree(tmp);
 221                         dev->atalk_ptr = NULL;
 222                 } else
 223                         iface = &tmp->next;
 224         }
 225         write_unlock_bh(&atalk_interfaces_lock);
 226 }
 227
 228 static struct atalk_iface *atif_add_device(struct net_device *dev,
 229                                            struct atalk_addr *sa)
 230 {
 231         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 232
 233         if (!iface)
 234                 goto out;
 235
 236         dev_hold(dev);
 237         iface->dev = dev;
 238         dev->atalk_ptr = iface;
 239         iface->address = *sa;
 240         iface->status = 0;
 241
 242         write_lock_bh(&atalk_interfaces_lock);
 243         iface->next = atalk_interfaces;
 244         atalk_interfaces = iface;
 245         write_unlock_bh(&atalk_interfaces_lock);
 246 out:
 247         return iface;
 248 }
 249
 250 /* Perform phase 2 AARP probing on our tentative address */
 251 static int atif_probe_device(struct atalk_iface *atif)
 252 {
 253         int netrange = ntohs(atif->nets.nr_lastnet) -
 254                         ntohs(atif->nets.nr_firstnet) + 1;
 255         int probe_net = ntohs(atif->address.s_net);
 256         int probe_node = atif->address.s_node;
 257         int netct, nodect;
 258
 259         /* Offset the network we start probing with */
 260         if (probe_net == ATADDR_ANYNET) {
 261                 probe_net = ntohs(atif->nets.nr_firstnet);
 262                 if (netrange)
 263                         probe_net += jiffies % netrange;
 264         }
 265         if (probe_node == ATADDR_ANYNODE)
 266                 probe_node = jiffies & 0xFF;
 267
 268         /* Scan the networks */
 269         atif->status |= ATIF_PROBE;
 270         for (netct = 0; netct <= netrange; netct++) {
 271                 /* Sweep the available nodes from a given start */
 272                 atif->address.s_net = htons(probe_net);
 273                 for (nodect = 0; nodect < 256; nodect++) {
 274                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 275                         if (atif->address.s_node > 0 &&
 276                             atif->address.s_node < 254) {
 277                                 /* Probe a proposed address */
 278                                 aarp_probe_network(atif);
 279
 280                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 281                                         atif->status &= ~ATIF_PROBE;
 282                                         return 0;
 283                                 }
 284                         }
 285                         atif->status &= ~ATIF_PROBE_FAIL;
 286                 }
 287                 probe_net++;
 288                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 289                         probe_net = ntohs(atif->nets.nr_firstnet);
 290         }
 291         atif->status &= ~ATIF_PROBE;
 292
 293         return -EADDRINUSE;     /* Network is full... */
 294 }
 295
 296
 297 /* Perform AARP probing for a proxy address */
 298 static int atif_proxy_probe_device(struct atalk_iface *atif,
 299                                    struct atalk_addr* proxy_addr)
 300 {
 301         int netrange = ntohs(atif->nets.nr_lastnet) -
 302                         ntohs(atif->nets.nr_firstnet) + 1;
 303         /* we probe the interface's network */
 304         int probe_net = ntohs(atif->address.s_net);
 305         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 306         int netct, nodect;
 307
 308         /* Offset the network we start probing with */
 309         if (probe_net == ATADDR_ANYNET) {
 310                 probe_net = ntohs(atif->nets.nr_firstnet);
 311                 if (netrange)
 312                         probe_net += jiffies % netrange;
 313         }
 314
 315         if (probe_node == ATADDR_ANYNODE)
 316                 probe_node = jiffies & 0xFF;
 317
 318         /* Scan the networks */
 319         for (netct = 0; netct <= netrange; netct++) {
 320                 /* Sweep the available nodes from a given start */
 321                 proxy_addr->s_net = htons(probe_net);
 322                 for (nodect = 0; nodect < 256; nodect++) {
 323                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 324                         if (proxy_addr->s_node > 0 &&
 325                             proxy_addr->s_node < 254) {
 326                                 /* Tell AARP to probe a proposed address */
 327                                 int ret = aarp_proxy_probe_network(atif,
 328                                                                     proxy_addr);
 329
 330                                 if (ret != -EADDRINUSE)
 331                                         return ret;
 332                         }
 333                 }
 334                 probe_net++;
 335                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 336                         probe_net = ntohs(atif->nets.nr_firstnet);
 337         }
 338
 339         return -EADDRINUSE;     /* Network is full... */
 340 }
 341
 342
 343 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 344 {
 345         struct atalk_iface *iface = dev->atalk_ptr;
 346         return iface ? &iface->address : NULL;
 347 }
 348
 349 static struct atalk_addr *atalk_find_primary(void)
 350 {
 351         struct atalk_iface *fiface = NULL;
 352         struct atalk_addr *retval;
 353         struct atalk_iface *iface;
 354
 355         /*
 356          * Return a point-to-point interface only if
 357          * there is no non-ptp interface available.
 358          */
 359         read_lock_bh(&atalk_interfaces_lock);
 360         for (iface = atalk_interfaces; iface; iface = iface->next) {
 361                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 362                         fiface = iface;
 363                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 364                         retval = &iface->address;
 365                         goto out;
 366                 }
 367         }
 368
 369         if (fiface)
 370                 retval = &fiface->address;
 371         else if (atalk_interfaces)
 372                 retval = &atalk_interfaces->address;
 373         else
 374                 retval = NULL;
 375 out:
 376         read_unlock_bh(&atalk_interfaces_lock);
 377         return retval;
 378 }
 379
 380 /*
 381  * Find a match for 'any network' - ie any of our interfaces with that
 382  * node number will do just nicely.
 383  */
 384 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 385 {
 386         struct atalk_iface *iface = dev->atalk_ptr;
 387
 388         if (!iface || iface->status & ATIF_PROBE)
 389                 goto out_err;
 390
 391         if (node != ATADDR_BCAST &&
 392             iface->address.s_node != node &&
 393             node != ATADDR_ANYNODE)
 394                 goto out_err;
 395 out:
 396         return iface;
 397 out_err:
 398         iface = NULL;
 399         goto out;
 400 }
 401
 402 /* Find a match for a specific network:node pair */
 403 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 404 {
 405         struct atalk_iface *iface;
 406
 407         read_lock_bh(&atalk_interfaces_lock);
 408         for (iface = atalk_interfaces; iface; iface = iface->next) {
 409                 if ((node == ATADDR_BCAST ||
 410                      node == ATADDR_ANYNODE ||
 411                      iface->address.s_node == node) &&
 412                     iface->address.s_net == net &&
 413                     !(iface->status & ATIF_PROBE))
 414                         break;
 415
 416                 /* XXXX.0 -- net.0 returns the iface associated with net */
 417                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 418                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 419                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 420                         break;
 421         }
 422         read_unlock_bh(&atalk_interfaces_lock);
 423         return iface;
 424 }
 425
 426
 427 /*
 428  * Find a route for an AppleTalk packet. This ought to get cached in
 429  * the socket (later on...). We know about host routes and the fact
 430  * that a route must be direct to broadcast.
 431  */
 432 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 433 {
 434         /*
 435          * we must search through all routes unless we find a
 436          * host route, because some host routes might overlap
 437          * network routes
 438          */
 439         struct atalk_route *net_route = NULL;
 440         struct atalk_route *r;
 441
 442         read_lock_bh(&atalk_routes_lock);
 443         for (r = atalk_routes; r; r = r->next) {
 444                 if (!(r->flags & RTF_UP))
 445                         continue;
 446
 447                 if (r->target.s_net == target->s_net) {
 448                         if (r->flags & RTF_HOST) {
 449                                 /*
 450                                  * if this host route is for the target,
 451                                  * the we're done
 452                                  */
 453                                 if (r->target.s_node == target->s_node)
 454                                         goto out;
 455                         } else
 456                                 /*
 457                                  * this route will work if there isn't a
 458                                  * direct host route, so cache it
 459                                  */
 460                                 net_route = r;
 461                 }
 462         }
 463
 464         /*
 465          * if we found a network route but not a direct host
 466          * route, then return it
 467          */
 468         if (net_route)
 469                 r = net_route;
 470         else if (atrtr_default.dev)
 471                 r = &atrtr_default;
 472         else /* No route can be found */
 473                 r = NULL;
 474 out:
 475         read_unlock_bh(&atalk_routes_lock);
 476         return r;
 477 }
 478
 479
 480 /*
 481  * Given an AppleTalk network, find the device to use. This can be
 482  * a simple lookup.
 483  */
 484 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 485 {
 486         struct atalk_route *atr = atrtr_find(sa);
 487         return atr ? atr->dev : NULL;
 488 }
 489
 490 /* Set up a default router */
 491 static void atrtr_set_default(struct net_device *dev)
 492 {
 493         atrtr_default.dev            = dev;
 494         atrtr_default.flags          = RTF_UP;
 495         atrtr_default.gateway.s_net  = htons(0);
 496         atrtr_default.gateway.s_node = 0;
 497 }
 498
 499 /*
 500  * Add a router. Basically make sure it looks valid and stuff the
 501  * entry in the list. While it uses netranges we always set them to one
 502  * entry to work like netatalk.
 503  */
 504 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 505 {
 506         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 507         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 508         struct atalk_route *rt;
 509         struct atalk_iface *iface, *riface;
 510         int retval = -EINVAL;
 511
 512         /*
 513          * Fixme: Raise/Lower a routing change semaphore for these
 514          * operations.
 515          */
 516
 517         /* Validate the request */
 518         if (ta->sat_family != AF_APPLETALK ||
 519             (!devhint && ga->sat_family != AF_APPLETALK))
 520                 goto out;
 521
 522         /* Now walk the routing table and make our decisions */
 523         write_lock_bh(&atalk_routes_lock);
 524         for (rt = atalk_routes; rt; rt = rt->next) {
 525                 if (r->rt_flags != rt->flags)
 526                         continue;
 527
 528                 if (ta->sat_addr.s_net == rt->target.s_net) {
 529                         if (!(rt->flags & RTF_HOST))
 530                                 break;
 531                         if (ta->sat_addr.s_node == rt->target.s_node)
 532                                 break;
 533                 }
 534         }
 535
 536         if (!devhint) {
 537                 riface = NULL;
 538
 539                 read_lock_bh(&atalk_interfaces_lock);
 540                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 541                         if (!riface &&
 542                             ntohs(ga->sat_addr.s_net) >=
 543                                         ntohs(iface->nets.nr_firstnet) &&
 544                             ntohs(ga->sat_addr.s_net) <=
 545                                         ntohs(iface->nets.nr_lastnet))
 546                                 riface = iface;
 547
 548                         if (ga->sat_addr.s_net == iface->address.s_net &&
 549                             ga->sat_addr.s_node == iface->address.s_node)
 550                                 riface = iface;
 551                 }
 552                 read_unlock_bh(&atalk_interfaces_lock);
 553
 554                 retval = -ENETUNREACH;
 555                 if (!riface)
 556                         goto out_unlock;
 557
 558                 devhint = riface->dev;
 559         }
 560
 561         if (!rt) {
 562                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 563
 564                 retval = -ENOBUFS;
 565                 if (!rt)
 566                         goto out_unlock;
 567
 568                 rt->next = atalk_routes;
 569                 atalk_routes = rt;
 570         }
 571
 572         /* Fill in the routing entry */
 573         rt->target  = ta->sat_addr;
 574         dev_hold(devhint);
 575         rt->dev     = devhint;
 576         rt->flags   = r->rt_flags;
 577         rt->gateway = ga->sat_addr;
 578
 579         retval = 0;
 580 out_unlock:
 581         write_unlock_bh(&atalk_routes_lock);
 582 out:
 583         return retval;
 584 }
 585
 586 /* Delete a route. Find it and discard it */
 587 static int atrtr_delete(struct atalk_addr * addr)
 588 {
 589         struct atalk_route **r = &atalk_routes;
 590         int retval = 0;
 591         struct atalk_route *tmp;
 592
 593         write_lock_bh(&atalk_routes_lock);
 594         while ((tmp = *r) != NULL) {
 595                 if (tmp->target.s_net == addr->s_net &&
 596                     (!(tmp->flags&RTF_GATEWAY) ||
 597                      tmp->target.s_node == addr->s_node)) {
 598                         *r = tmp->next;
 599                         dev_put(tmp->dev);
 600                         kfree(tmp);
 601                         goto out;
 602                 }
 603                 r = &tmp->next;
 604         }
 605         retval = -ENOENT;
 606 out:
 607         write_unlock_bh(&atalk_routes_lock);
 608         return retval;
 609 }
 610
 611 /*
 612  * Called when a device is downed. Just throw away any routes
 613  * via it.
 614  */
 615 static void atrtr_device_down(struct net_device *dev)
 616 {
 617         struct atalk_route **r = &atalk_routes;
 618         struct atalk_route *tmp;
 619
 620         write_lock_bh(&atalk_routes_lock);
 621         while ((tmp = *r) != NULL) {
 622                 if (tmp->dev == dev) {
 623                         *r = tmp->next;
 624                         dev_put(dev);
 625                         kfree(tmp);
 626                 } else
 627                         r = &tmp->next;
 628         }
 629         write_unlock_bh(&atalk_routes_lock);
 630
 631         if (atrtr_default.dev == dev)
 632                 atrtr_set_default(NULL);
 633 }
 634
 635 /* Actually down the interface */
 636 static inline void atalk_dev_down(struct net_device *dev)
 637 {
 638         atrtr_device_down(dev); /* Remove all routes for the device */
 639         aarp_device_down(dev);  /* Remove AARP entries for the device */
 640         atif_drop_device(dev);  /* Remove the device */
 641 }
 642
 643 /*
 644  * A device event has occurred. Watch for devices going down and
 645  * delete our use of them (iface and route).
 646  */
 647 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 648                             void *ptr)
 649 {
 650         if (event == NETDEV_DOWN)
 651                 /* Discard any use of this */
 652                 atalk_dev_down(ptr);
 653
 654         return NOTIFY_DONE;
 655 }
 656
 657 /* ioctl calls. Shouldn't even need touching */
 658 /* Device configuration ioctl calls */
 659 static int atif_ioctl(int cmd, void __user *arg)
 660 {
 661         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 662         struct ifreq atreq;
 663         struct atalk_netrange *nr;
 664         struct sockaddr_at *sa;
 665         struct net_device *dev;
 666         struct atalk_iface *atif;
 667         int ct;
 668         int limit;
 669         struct rtentry rtdef;
 670         int add_route;
 671
 672         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 673                 return -EFAULT;
 674
 675         dev = __dev_get_by_name(atreq.ifr_name);
 676         if (!dev)
 677                 return -ENODEV;
 678
 679         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 680         atif = atalk_find_dev(dev);
 681
 682         switch (cmd) {
 683                 case SIOCSIFADDR:
 684                         if (!capable(CAP_NET_ADMIN))
 685                                 return -EPERM;
 686                         if (sa->sat_family != AF_APPLETALK)
 687                                 return -EINVAL;
 688                         if (dev->type != ARPHRD_ETHER &&
 689                             dev->type != ARPHRD_LOOPBACK &&
 690                             dev->type != ARPHRD_LOCALTLK &&
 691                             dev->type != ARPHRD_PPP)
 692                                 return -EPROTONOSUPPORT;
 693
 694                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 695                         add_route = 1;
 696
 697                         /*
 698                          * if this is a point-to-point iface, and we already
 699                          * have an iface for this AppleTalk address, then we
 700                          * should not add a route
 701                          */
 702                         if ((dev->flags & IFF_POINTOPOINT) &&
 703                             atalk_find_interface(sa->sat_addr.s_net,
 704                                                  sa->sat_addr.s_node)) {
 705                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 706                                                   "interface added with "
 707                                                   "existing address\n");
 708                                 add_route = 0;
 709                         }
 710
 711                         /*
 712                          * Phase 1 is fine on LocalTalk but we don't do
 713                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 714                          */
 715                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 716                                 return -EPROTONOSUPPORT;
 717                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 718                             sa->sat_addr.s_node == 254)
 719                                 return -EINVAL;
 720                         if (atif) {
 721                                 /* Already setting address */
 722                                 if (atif->status & ATIF_PROBE)
 723                                         return -EBUSY;
 724
 725                                 atif->address.s_net  = sa->sat_addr.s_net;
 726                                 atif->address.s_node = sa->sat_addr.s_node;
 727                                 atrtr_device_down(dev); /* Flush old routes */
 728                         } else {
 729                                 atif = atif_add_device(dev, &sa->sat_addr);
 730                                 if (!atif)
 731                                         return -ENOMEM;
 732                         }
 733                         atif->nets = *nr;
 734
 735                         /*
 736                          * Check if the chosen address is used. If so we
 737                          * error and atalkd will try another.
 738                          */
 739
 740                         if (!(dev->flags & IFF_LOOPBACK) &&
 741                             !(dev->flags & IFF_POINTOPOINT) &&
 742                             atif_probe_device(atif) < 0) {
 743                                 atif_drop_device(dev);
 744                                 return -EADDRINUSE;
 745                         }
 746
 747                         /* Hey it worked - add the direct routes */
 748                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 749                         sa->sat_family = AF_APPLETALK;
 750                         sa->sat_addr.s_net  = atif->address.s_net;
 751                         sa->sat_addr.s_node = atif->address.s_node;
 752                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 753                         rtdef.rt_flags = RTF_UP;
 754                         sa->sat_family = AF_APPLETALK;
 755                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 756                         if (dev->flags & IFF_LOOPBACK ||
 757                             dev->flags & IFF_POINTOPOINT)
 758                                 rtdef.rt_flags |= RTF_HOST;
 759
 760                         /* Routerless initial state */
 761                         if (nr->nr_firstnet == htons(0) &&
 762                             nr->nr_lastnet == htons(0xFFFE)) {
 763                                 sa->sat_addr.s_net = atif->address.s_net;
 764                                 atrtr_create(&rtdef, dev);
 765                                 atrtr_set_default(dev);
 766                         } else {
 767                                 limit = ntohs(nr->nr_lastnet);
 768                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 769                                         printk(KERN_WARNING "Too many routes/"
 770                                                             "iface.\n");
 771                                         return -EINVAL;
 772                                 }
 773                                 if (add_route)
 774                                         for (ct = ntohs(nr->nr_firstnet);
 775                                              ct <= limit; ct++) {
 776                                                 sa->sat_addr.s_net = htons(ct);
 777                                                 atrtr_create(&rtdef, dev);
 778                                         }
 779                         }
 780                         dev_mc_add(dev, aarp_mcast, 6, 1);
 781                         return 0;
 782
 783                 case SIOCGIFADDR:
 784                         if (!atif)
 785                                 return -EADDRNOTAVAIL;
 786
 787                         sa->sat_family = AF_APPLETALK;
 788                         sa->sat_addr = atif->address;
 789                         break;
 790
 791                 case SIOCGIFBRDADDR:
 792                         if (!atif)
 793                                 return -EADDRNOTAVAIL;
 794
 795                         sa->sat_family = AF_APPLETALK;
 796                         sa->sat_addr.s_net = atif->address.s_net;
 797                         sa->sat_addr.s_node = ATADDR_BCAST;
 798                         break;
 799
 800                 case SIOCATALKDIFADDR:
 801                 case SIOCDIFADDR:
 802                         if (!capable(CAP_NET_ADMIN))
 803                                 return -EPERM;
 804                         if (sa->sat_family != AF_APPLETALK)
 805                                 return -EINVAL;
 806                         atalk_dev_down(dev);
 807                         break;
 808
 809                 case SIOCSARP:
 810                         if (!capable(CAP_NET_ADMIN))
 811                                 return -EPERM;
 812                         if (sa->sat_family != AF_APPLETALK)
 813                                 return -EINVAL;
 814                         if (!atif)
 815                                 return -EADDRNOTAVAIL;
 816
 817                         /*
 818                          * for now, we only support proxy AARP on ELAP;
 819                          * we should be able to do it for LocalTalk, too.
 820                          */
 821                         if (dev->type != ARPHRD_ETHER)
 822                                 return -EPROTONOSUPPORT;
 823
 824                         /*
 825                          * atif points to the current interface on this network;
 826                          * we aren't concerned about its current status (at
 827                          * least for now), but it has all the settings about
 828                          * the network we're going to probe. Consequently, it
 829                          * must exist.
 830                          */
 831                         if (!atif)
 832                                 return -EADDRNOTAVAIL;
 833
 834                         nr = (struct atalk_netrange *)&(atif->nets);
 835                         /*
 836                          * Phase 1 is fine on Localtalk but we don't do
 837                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 838                          */
 839                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 840                                 return -EPROTONOSUPPORT;
 841
 842                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 843                             sa->sat_addr.s_node == 254)
 844                                 return -EINVAL;
 845
 846                         /*
 847                          * Check if the chosen address is used. If so we
 848                          * error and ATCP will try another.
 849                          */
 850                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 851                                 return -EADDRINUSE;
 852
 853                         /*
 854                          * We now have an address on the local network, and
 855                          * the AARP code will defend it for us until we take it
 856                          * down. We don't set up any routes right now, because
 857                          * ATCP will install them manually via SIOCADDRT.
 858                          */
 859                         break;
 860
 861                 case SIOCDARP:
 862                         if (!capable(CAP_NET_ADMIN))
 863                                 return -EPERM;
 864                         if (sa->sat_family != AF_APPLETALK)
 865                                 return -EINVAL;
 866                         if (!atif)
 867                                 return -EADDRNOTAVAIL;
 868
 869                         /* give to aarp module to remove proxy entry */
 870                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 871                         return 0;
 872         }
 873
 874         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 875 }
 876
 877 /* Routing ioctl() calls */
 878 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 879 {
 880         struct rtentry rt;
 881
 882         if (copy_from_user(&rt, arg, sizeof(rt)))
 883                 return -EFAULT;
 884
 885         switch (cmd) {
 886                 case SIOCDELRT:
 887                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 888                                 return -EINVAL;
 889                         return atrtr_delete(&((struct sockaddr_at *)
 890                                                 &rt.rt_dst)->sat_addr);
 891
 892                 case SIOCADDRT: {
 893                         struct net_device *dev = NULL;
 894                         if (rt.rt_dev) {
 895                                 char name[IFNAMSIZ];
 896                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 897                                         return -EFAULT;
 898                                 name[IFNAMSIZ-1] = '\0';
 899                                 dev = __dev_get_by_name(name);
 900                                 if (!dev)
 901                                         return -ENODEV;
 902                         }
 903                         return atrtr_create(&rt, dev);
 904                 }
 905         }
 906         return -EINVAL;
 907 }
 908
 909 /**************************************************************************\
 910 *                                                                          *
 911 * Handling for system calls applied via the various interfaces to an       *
 912 * AppleTalk socket object.                                                 *
 913 *                                                                          *
 914 \**************************************************************************/
 915
 916 /*
 917  * Checksum: This is 'optional'. It's quite likely also a good
 918  * candidate for assembler hackery 8)
 919  */
 920 static unsigned long atalk_sum_partial(const unsigned char *data,
 921                                        int len, unsigned long sum)
 922 {
 923         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 924         while (len--) {
 925                 sum += *data;
 926                 sum <<= 1;
 927                 if (sum & 0x10000) {
 928                         sum++;
 929                         sum &= 0xffff;
 930                 }
 931                 data++;
 932         }
 933         return sum;
 934 }
 935
 936 /*  Checksum skb data --  similar to skb_checksum  */
 937 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 938                                    int len, unsigned long sum)
 939 {
 940         int end = skb_headlen(skb);
 941         int i, copy;
 942
 943         /* checksum stuff in header space */
 944         if ((copy = end - offset) > 0) {
 945                 if (copy > len)
 946                         copy = len;
 947                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 948                 if ( (len -= copy) == 0)
 949                         return sum;
 950
 951                 offset += copy;
 952         }
 953
 954         /* checksum stuff in frags */
 955         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 956                 BUG_TRAP(len >= 0);
 957
 958                 end = offset + skb_shinfo(skb)->frags[i].size;
 959                 if ((copy = end - offset) > 0) {
 960                         u8 *vaddr;
 961                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 962
 963                         if (copy > len)
 964                                 copy = len;
 965                         vaddr = kmap_skb_frag(frag);
 966                         sum = atalk_sum_partial(vaddr + frag->page_offset,
 967                                                 copy, sum);
 968                         kunmap_skb_frag(vaddr);
 969
 970                         if (!(len -= copy))
 971                                 return sum;
 972                         offset += copy;
 973                 }
 974         }
 975
 976         if (skb_shinfo(skb)->frag_list) {
 977                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
 978
 979                 for (; list; list = list->next) {
 980                         BUG_TRAP(len >= 0);
 981
 982                         end = offset + list->len;
 983                         if ((copy = end - offset) > 0) {
 984                                 if (copy > len)
 985                                         copy = len;
 986                                 sum = atalk_sum_skb(list, 0, copy, sum);
 987                                 if ((len -= copy) == 0)
 988                                         return sum;
 989                                 offset += copy;
 990                         }
 991                 }
 992         }
 993
 994         BUG_ON(len > 0);
 995
 996         return sum;
 997 }
 998
 999 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1000 {
1001         unsigned long sum;
1002
1003         /* skip header 4 bytes */
1004         sum = atalk_sum_skb(skb, 4, len-4, 0);
1005
1006         /* Use 0xFFFF for 0. 0 itself means none */
1007         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1008 }
1009
1010 static struct proto ddp_proto = {
1011         .name     = "DDP",
1012         .owner    = THIS_MODULE,
1013         .obj_size = sizeof(struct atalk_sock),
1014 };
1015
1016 /*
1017  * Create a socket. Initialise the socket, blank the addresses
1018  * set the state.
1019  */
1020 static int atalk_create(struct socket *sock, int protocol)
1021 {
1022         struct sock *sk;
1023         int rc = -ESOCKTNOSUPPORT;
1024
1025         /*
1026          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1027          * and gives you the full ELAP frame. Should be handy for CAP 8)
1028          */
1029         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1030                 goto out;
1031         rc = -ENOMEM;
1032         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1033         if (!sk)
1034                 goto out;
1035         rc = 0;
1036         sock->ops = &atalk_dgram_ops;
1037         sock_init_data(sock, sk);
1038
1039         /* Checksums on by default */
1040         sock_set_flag(sk, SOCK_ZAPPED);
1041 out:
1042         return rc;
1043 }
1044
1045 /* Free a socket. No work needed */
1046 static int atalk_release(struct socket *sock)
1047 {
1048         struct sock *sk = sock->sk;
1049
1050         if (sk) {
1051                 sock_orphan(sk);
1052                 sock->sk = NULL;
1053                 atalk_destroy_socket(sk);
1054         }
1055         return 0;
1056 }
1057
1058 /**
1059  * atalk_pick_and_bind_port - Pick a source port when one is not given
1060  * @sk - socket to insert into the tables
1061  * @sat - address to search for
1062  *
1063  * Pick a source port when one is not given. If we can find a suitable free
1064  * one, we insert the socket into the tables using it.
1065  *
1066  * This whole operation must be atomic.
1067  */
1068 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1069 {
1070         int retval;
1071
1072         write_lock_bh(&atalk_sockets_lock);
1073
1074         for (sat->sat_port = ATPORT_RESERVED;
1075              sat->sat_port < ATPORT_LAST;
1076              sat->sat_port++) {
1077                 struct sock *s;
1078                 struct hlist_node *node;
1079
1080                 sk_for_each(s, node, &atalk_sockets) {
1081                         struct atalk_sock *at = at_sk(s);
1082
1083                         if (at->src_net == sat->sat_addr.s_net &&
1084                             at->src_node == sat->sat_addr.s_node &&
1085                             at->src_port == sat->sat_port)
1086                                 goto try_next_port;
1087                 }
1088
1089                 /* Wheee, it's free, assign and insert. */
1090                 __atalk_insert_socket(sk);
1091                 at_sk(sk)->src_port = sat->sat_port;
1092                 retval = 0;
1093                 goto out;
1094
1095 try_next_port:;
1096         }
1097
1098         retval = -EBUSY;
1099 out:
1100         write_unlock_bh(&atalk_sockets_lock);
1101         return retval;
1102 }
1103
1104 static int atalk_autobind(struct sock *sk)
1105 {
1106         struct atalk_sock *at = at_sk(sk);
1107         struct sockaddr_at sat;
1108         struct atalk_addr *ap = atalk_find_primary();
1109         int n = -EADDRNOTAVAIL;
1110
1111         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1112                 goto out;
1113
1114         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1115         at->src_node = sat.sat_addr.s_node = ap->s_node;
1116
1117         n = atalk_pick_and_bind_port(sk, &sat);
1118         if (!n)
1119                 sock_reset_flag(sk, SOCK_ZAPPED);
1120 out:
1121         return n;
1122 }
1123
1124 /* Set the address 'our end' of the connection */
1125 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1126 {
1127         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1128         struct sock *sk = sock->sk;
1129         struct atalk_sock *at = at_sk(sk);
1130
1131         if (!sock_flag(sk, SOCK_ZAPPED) ||
1132             addr_len != sizeof(struct sockaddr_at))
1133                 return -EINVAL;
1134
1135         if (addr->sat_family != AF_APPLETALK)
1136                 return -EAFNOSUPPORT;
1137
1138         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1139                 struct atalk_addr *ap = atalk_find_primary();
1140
1141                 if (!ap)
1142                         return -EADDRNOTAVAIL;
1143
1144                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1145                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1146         } else {
1147                 if (!atalk_find_interface(addr->sat_addr.s_net,
1148                                           addr->sat_addr.s_node))
1149                         return -EADDRNOTAVAIL;
1150
1151                 at->src_net  = addr->sat_addr.s_net;
1152                 at->src_node = addr->sat_addr.s_node;
1153         }
1154
1155         if (addr->sat_port == ATADDR_ANYPORT) {
1156                 int n = atalk_pick_and_bind_port(sk, addr);
1157
1158                 if (n < 0)
1159                         return n;
1160         } else {
1161                 at->src_port = addr->sat_port;
1162
1163                 if (atalk_find_or_insert_socket(sk, addr))
1164                         return -EADDRINUSE;
1165         }
1166
1167         sock_reset_flag(sk, SOCK_ZAPPED);
1168         return 0;
1169 }
1170
1171 /* Set the address we talk to */
1172 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1173                          int addr_len, int flags)
1174 {
1175         struct sock *sk = sock->sk;
1176         struct atalk_sock *at = at_sk(sk);
1177         struct sockaddr_at *addr;
1178
1179         sk->sk_state   = TCP_CLOSE;
1180         sock->state = SS_UNCONNECTED;
1181
1182         if (addr_len != sizeof(*addr))
1183                 return -EINVAL;
1184
1185         addr = (struct sockaddr_at *)uaddr;
1186
1187         if (addr->sat_family != AF_APPLETALK)
1188                 return -EAFNOSUPPORT;
1189
1190         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1191             !sock_flag(sk, SOCK_BROADCAST)) {
1192 #if 1
1193                 printk(KERN_WARNING "%s is broken and did not set "
1194                                     "SO_BROADCAST. It will break when 2.2 is "
1195                                     "released.\n",
1196                         current->comm);
1197 #else
1198                 return -EACCES;
1199 #endif
1200         }
1201
1202         if (sock_flag(sk, SOCK_ZAPPED))
1203                 if (atalk_autobind(sk) < 0)
1204                         return -EBUSY;
1205
1206         if (!atrtr_get_dev(&addr->sat_addr))
1207                 return -ENETUNREACH;
1208
1209         at->dest_port = addr->sat_port;
1210         at->dest_net  = addr->sat_addr.s_net;
1211         at->dest_node = addr->sat_addr.s_node;
1212
1213         sock->state  = SS_CONNECTED;
1214         sk->sk_state = TCP_ESTABLISHED;
1215         return 0;
1216 }
1217
1218 /*
1219  * Find the name of an AppleTalk socket. Just copy the right
1220  * fields into the sockaddr.
1221  */
1222 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1223                          int *uaddr_len, int peer)
1224 {
1225         struct sockaddr_at sat;
1226         struct sock *sk = sock->sk;
1227         struct atalk_sock *at = at_sk(sk);
1228
1229         if (sock_flag(sk, SOCK_ZAPPED))
1230                 if (atalk_autobind(sk) < 0)
1231                         return -ENOBUFS;
1232
1233         *uaddr_len = sizeof(struct sockaddr_at);
1234
1235         if (peer) {
1236                 if (sk->sk_state != TCP_ESTABLISHED)
1237                         return -ENOTCONN;
1238
1239                 sat.sat_addr.s_net  = at->dest_net;
1240                 sat.sat_addr.s_node = at->dest_node;
1241                 sat.sat_port        = at->dest_port;
1242         } else {
1243                 sat.sat_addr.s_net  = at->src_net;
1244                 sat.sat_addr.s_node = at->src_node;
1245                 sat.sat_port        = at->src_port;
1246         }
1247
1248         sat.sat_family = AF_APPLETALK;
1249         memcpy(uaddr, &sat, sizeof(sat));
1250         return 0;
1251 }
1252
1253 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1254 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1255 {
1256         return skb->data[12] == 22;
1257 }
1258
1259 static int handle_ip_over_ddp(struct sk_buff *skb)
1260 {
1261         struct net_device *dev = __dev_get_by_name("ipddp0");
1262         struct net_device_stats *stats;
1263
1264         /* This needs to be able to handle ipddp"N" devices */
1265         if (!dev)
1266                 return -ENODEV;
1267
1268         skb->protocol = htons(ETH_P_IP);
1269         skb_pull(skb, 13);
1270         skb->dev   = dev;
1271         skb_reset_transport_header(skb);
1272
1273         stats = dev->priv;
1274         stats->rx_packets++;
1275         stats->rx_bytes += skb->len + 13;
1276         netif_rx(skb);  /* Send the SKB up to a higher place. */
1277         return 0;
1278 }
1279 #else
1280 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1281 #define is_ip_over_ddp(skb) 0
1282 #define handle_ip_over_ddp(skb) 0
1283 #endif
1284
1285 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1286                                struct ddpehdr *ddp, __u16 len_hops,
1287                                int origlen)
1288 {
1289         struct atalk_route *rt;
1290         struct atalk_addr ta;
1291
1292         /*
1293          * Don't route multicast, etc., packets, or packets sent to "this
1294          * network"
1295          */
1296         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1297                 /*
1298                  * FIXME:
1299                  *
1300                  * Can it ever happen that a packet is from a PPP iface and
1301                  * needs to be broadcast onto the default network?
1302                  */
1303                 if (dev->type == ARPHRD_PPP)
1304                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1305                                           "packet received from PPP iface\n");
1306                 goto free_it;
1307         }
1308
1309         ta.s_net  = ddp->deh_dnet;
1310         ta.s_node = ddp->deh_dnode;
1311
1312         /* Route the packet */
1313         rt = atrtr_find(&ta);
1314         /* increment hops count */
1315         len_hops += 1 << 10;
1316         if (!rt || !(len_hops & (15 << 10)))
1317                 goto free_it;
1318
1319         /* FIXME: use skb->cb to be able to use shared skbs */
1320
1321         /*
1322          * Route goes through another gateway, so set the target to the
1323          * gateway instead.
1324          */
1325
1326         if (rt->flags & RTF_GATEWAY) {
1327                 ta.s_net  = rt->gateway.s_net;
1328                 ta.s_node = rt->gateway.s_node;
1329         }
1330
1331         /* Fix up skb->len field */
1332         skb_trim(skb, min_t(unsigned int, origlen,
1333                             (rt->dev->hard_header_len +
1334                              ddp_dl->header_length + (len_hops & 1023))));
1335
1336         /* FIXME: use skb->cb to be able to use shared skbs */
1337         ddp->deh_len_hops = htons(len_hops);
1338
1339         /*
1340          * Send the buffer onwards
1341          *
1342          * Now we must always be careful. If it's come from LocalTalk to
1343          * EtherTalk it might not fit
1344          *
1345          * Order matters here: If a packet has to be copied to make a new
1346          * headroom (rare hopefully) then it won't need unsharing.
1347          *
1348          * Note. ddp-> becomes invalid at the realloc.
1349          */
1350         if (skb_headroom(skb) < 22) {
1351                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1352                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1353                 kfree_skb(skb);
1354                 if (!nskb)
1355                         goto out;
1356                 skb = nskb;
1357         } else
1358                 skb = skb_unshare(skb, GFP_ATOMIC);
1359
1360         /*
1361          * If the buffer didn't vanish into the lack of space bitbucket we can
1362          * send it.
1363          */
1364         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1365                 goto free_it;
1366 out:
1367         return;
1368 free_it:
1369         kfree_skb(skb);
1370 }
1371
1372 /**
1373  *      atalk_rcv - Receive a packet (in skb) from device dev
1374  *      @skb - packet received
1375  *      @dev - network device where the packet comes from
1376  *      @pt - packet type
1377  *
1378  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1379  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1380  *      is the DDP header, skb->len is the DDP length. The physical headers
1381  *      have been extracted. PPP should probably pass frames marked as for this
1382  *      layer.  [ie ARPHRD_ETHERTALK]
1383  */
1384 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1385                      struct packet_type *pt, struct net_device *orig_dev)
1386 {
1387         struct ddpehdr *ddp;
1388         struct sock *sock;
1389         struct atalk_iface *atif;
1390         struct sockaddr_at tosat;
1391         int origlen;
1392         __u16 len_hops;
1393
1394         /* Don't mangle buffer if shared */
1395         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1396                 goto out;
1397
1398         /* Size check and make sure header is contiguous */
1399         if (!pskb_may_pull(skb, sizeof(*ddp)))
1400                 goto freeit;
1401
1402         ddp = ddp_hdr(skb);
1403
1404         len_hops = ntohs(ddp->deh_len_hops);
1405
1406         /* Trim buffer in case of stray trailing data */
1407         origlen = skb->len;
1408         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1409
1410         /*
1411          * Size check to see if ddp->deh_len was crap
1412          * (Otherwise we'll detonate most spectacularly
1413          * in the middle of atalk_checksum() or recvmsg()).
1414          */
1415         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1416                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1417                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1418                 goto freeit;
1419         }
1420
1421         /*
1422          * Any checksums. Note we don't do htons() on this == is assumed to be
1423          * valid for net byte orders all over the networking code...
1424          */
1425         if (ddp->deh_sum &&
1426             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1427                 /* Not a valid AppleTalk frame - dustbin time */
1428                 goto freeit;
1429
1430         /* Check the packet is aimed at us */
1431         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1432                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1433         else
1434                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1435
1436         if (!atif) {
1437                 /* Not ours, so we route the packet via the correct
1438                  * AppleTalk iface
1439                  */
1440                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1441                 goto out;
1442         }
1443
1444         /* if IP over DDP is not selected this code will be optimized out */
1445         if (is_ip_over_ddp(skb))
1446                 return handle_ip_over_ddp(skb);
1447         /*
1448          * Which socket - atalk_search_socket() looks for a *full match*
1449          * of the <net, node, port> tuple.
1450          */
1451         tosat.sat_addr.s_net  = ddp->deh_dnet;
1452         tosat.sat_addr.s_node = ddp->deh_dnode;
1453         tosat.sat_port        = ddp->deh_dport;
1454
1455         sock = atalk_search_socket(&tosat, atif);
1456         if (!sock) /* But not one of our sockets */
1457                 goto freeit;
1458
1459         /* Queue packet (standard) */
1460         skb->sk = sock;
1461
1462         if (sock_queue_rcv_skb(sock, skb) < 0)
1463                 goto freeit;
1464 out:
1465         return 0;
1466 freeit:
1467         kfree_skb(skb);
1468         goto out;
1469 }
1470
1471 /*
1472  * Receive a LocalTalk frame. We make some demands on the caller here.
1473  * Caller must provide enough headroom on the packet to pull the short
1474  * header and append a long one.
1475  */
1476 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1477                      struct packet_type *pt, struct net_device *orig_dev)
1478 {
1479         /* Expand any short form frames */
1480         if (skb_mac_header(skb)[2] == 1) {
1481                 struct ddpehdr *ddp;
1482                 /* Find our address */
1483                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1484
1485                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1486                         goto freeit;
1487
1488                 /* Don't mangle buffer if shared */
1489                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1490                         return 0;
1491
1492                 /*
1493                  * The push leaves us with a ddephdr not an shdr, and
1494                  * handily the port bytes in the right place preset.
1495                  */
1496                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1497
1498                 /* Now fill in the long header */
1499
1500                 /*
1501                  * These two first. The mac overlays the new source/dest
1502                  * network information so we MUST copy these before
1503                  * we write the network numbers !
1504                  */
1505
1506                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1507                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1508
1509                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1510                 ddp->deh_snet  = ap->s_net;
1511                 ddp->deh_sum   = 0;             /* No checksum */
1512                 /*
1513                  * Not sure about this bit...
1514                  */
1515                 /* Non routable, so force a drop if we slip up later */
1516                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1517         }
1518         skb_reset_transport_header(skb);
1519
1520         return atalk_rcv(skb, dev, pt, orig_dev);
1521 freeit:
1522         kfree_skb(skb);
1523         return 0;
1524 }
1525
1526 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1527                          size_t len)
1528 {
1529         struct sock *sk = sock->sk;
1530         struct atalk_sock *at = at_sk(sk);
1531         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1532         int flags = msg->msg_flags;
1533         int loopback = 0;
1534         struct sockaddr_at local_satalk, gsat;
1535         struct sk_buff *skb;
1536         struct net_device *dev;
1537         struct ddpehdr *ddp;
1538         int size;
1539         struct atalk_route *rt;
1540         int err;
1541
1542         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1543                 return -EINVAL;
1544
1545         if (len > DDP_MAXSZ)
1546                 return -EMSGSIZE;
1547
1548         if (usat) {
1549                 if (sock_flag(sk, SOCK_ZAPPED))
1550                         if (atalk_autobind(sk) < 0)
1551                                 return -EBUSY;
1552
1553                 if (msg->msg_namelen < sizeof(*usat) ||
1554                     usat->sat_family != AF_APPLETALK)
1555                         return -EINVAL;
1556
1557                 /* netatalk doesn't implement this check */
1558                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1559                     !sock_flag(sk, SOCK_BROADCAST)) {
1560                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1561                                          "it will break before 2.2\n");
1562 #if 0
1563                         return -EPERM;
1564 #endif
1565                 }
1566         } else {
1567                 if (sk->sk_state != TCP_ESTABLISHED)
1568                         return -ENOTCONN;
1569                 usat = &local_satalk;
1570                 usat->sat_family      = AF_APPLETALK;
1571                 usat->sat_port        = at->dest_port;
1572                 usat->sat_addr.s_node = at->dest_node;
1573                 usat->sat_addr.s_net  = at->dest_net;
1574         }
1575
1576         /* Build a packet */
1577         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1578
1579         /* For headers */
1580         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1581
1582         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1583                 rt = atrtr_find(&usat->sat_addr);
1584         } else {
1585                 struct atalk_addr at_hint;
1586
1587                 at_hint.s_node = 0;
1588                 at_hint.s_net  = at->src_net;
1589
1590                 rt = atrtr_find(&at_hint);
1591         }
1592         if (!rt)
1593                 return -ENETUNREACH;
1594
1595         dev = rt->dev;
1596
1597         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1598                         sk, size, dev->name);
1599
1600         size += dev->hard_header_len;
1601         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1602         if (!skb)
1603                 return err;
1604
1605         skb->sk = sk;
1606         skb_reserve(skb, ddp_dl->header_length);
1607         skb_reserve(skb, dev->hard_header_len);
1608         skb->dev = dev;
1609
1610         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1611
1612         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1613         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1614         ddp->deh_dnet  = usat->sat_addr.s_net;
1615         ddp->deh_snet  = at->src_net;
1616         ddp->deh_dnode = usat->sat_addr.s_node;
1617         ddp->deh_snode = at->src_node;
1618         ddp->deh_dport = usat->sat_port;
1619         ddp->deh_sport = at->src_port;
1620
1621         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1622
1623         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1624         if (err) {
1625                 kfree_skb(skb);
1626                 return -EFAULT;
1627         }
1628
1629         if (sk->sk_no_check == 1)
1630                 ddp->deh_sum = 0;
1631         else
1632                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1633
1634         /*
1635          * Loopback broadcast packets to non gateway targets (ie routes
1636          * to group we are in)
1637          */
1638         if (ddp->deh_dnode == ATADDR_BCAST &&
1639             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1640                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1641
1642                 if (skb2) {
1643                         loopback = 1;
1644                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1645                         if (aarp_send_ddp(dev, skb2,
1646                                           &usat->sat_addr, NULL) == -1)
1647                                 kfree_skb(skb2);
1648                                 /* else queued/sent above in the aarp queue */
1649                 }
1650         }
1651
1652         if (dev->flags & IFF_LOOPBACK || loopback) {
1653                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1654                 /* loop back */
1655                 skb_orphan(skb);
1656                 if (ddp->deh_dnode == ATADDR_BCAST) {
1657                         struct atalk_addr at_lo;
1658
1659                         at_lo.s_node = 0;
1660                         at_lo.s_net  = 0;
1661
1662                         rt = atrtr_find(&at_lo);
1663                         if (!rt) {
1664                                 kfree_skb(skb);
1665                                 return -ENETUNREACH;
1666                         }
1667                         dev = rt->dev;
1668                         skb->dev = dev;
1669                 }
1670                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1671         } else {
1672                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1673                 if (rt->flags & RTF_GATEWAY) {
1674                     gsat.sat_addr = rt->gateway;
1675                     usat = &gsat;
1676                 }
1677
1678                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1679                         kfree_skb(skb);
1680                 /* else queued/sent above in the aarp queue */
1681         }
1682         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1683
1684         return len;
1685 }
1686
1687 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1688                          size_t size, int flags)
1689 {
1690         struct sock *sk = sock->sk;
1691         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1692         struct ddpehdr *ddp;
1693         int copied = 0;
1694         int offset = 0;
1695         int err = 0;
1696         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1697                                                 flags & MSG_DONTWAIT, &err);
1698         if (!skb)
1699                 return err;
1700
1701         /* FIXME: use skb->cb to be able to use shared skbs */
1702         ddp = ddp_hdr(skb);
1703         copied = ntohs(ddp->deh_len_hops) & 1023;
1704
1705         if (sk->sk_type != SOCK_RAW) {
1706                 offset = sizeof(*ddp);
1707                 copied -= offset;
1708         }
1709
1710         if (copied > size) {
1711                 copied = size;
1712                 msg->msg_flags |= MSG_TRUNC;
1713         }
1714         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1715
1716         if (!err) {
1717                 if (sat) {
1718                         sat->sat_family      = AF_APPLETALK;
1719                         sat->sat_port        = ddp->deh_sport;
1720                         sat->sat_addr.s_node = ddp->deh_snode;
1721                         sat->sat_addr.s_net  = ddp->deh_snet;
1722                 }
1723                 msg->msg_namelen = sizeof(*sat);
1724         }
1725
1726         skb_free_datagram(sk, skb);     /* Free the datagram. */
1727         return err ? : copied;
1728 }
1729
1730
1731 /*
1732  * AppleTalk ioctl calls.
1733  */
1734 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1735 {
1736         int rc = -ENOIOCTLCMD;
1737         struct sock *sk = sock->sk;
1738         void __user *argp = (void __user *)arg;
1739
1740         switch (cmd) {
1741                 /* Protocol layer */
1742                 case TIOCOUTQ: {
1743                         long amount = sk->sk_sndbuf -
1744                                       atomic_read(&sk->sk_wmem_alloc);
1745
1746                         if (amount < 0)
1747                                 amount = 0;
1748                         rc = put_user(amount, (int __user *)argp);
1749                         break;
1750                 }
1751                 case TIOCINQ: {
1752                         /*
1753                          * These two are safe on a single CPU system as only
1754                          * user tasks fiddle here
1755                          */
1756                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1757                         long amount = 0;
1758
1759                         if (skb)
1760                                 amount = skb->len - sizeof(struct ddpehdr);
1761                         rc = put_user(amount, (int __user *)argp);
1762                         break;
1763                 }
1764                 case SIOCGSTAMP:
1765                         rc = sock_get_timestamp(sk, argp);
1766                         break;
1767                 case SIOCGSTAMPNS:
1768                         rc = sock_get_timestampns(sk, argp);
1769                         break;
1770                 /* Routing */
1771                 case SIOCADDRT:
1772                 case SIOCDELRT:
1773                         rc = -EPERM;
1774                         if (capable(CAP_NET_ADMIN))
1775                                 rc = atrtr_ioctl(cmd, argp);
1776                         break;
1777                 /* Interface */
1778                 case SIOCGIFADDR:
1779                 case SIOCSIFADDR:
1780                 case SIOCGIFBRDADDR:
1781                 case SIOCATALKDIFADDR:
1782                 case SIOCDIFADDR:
1783                 case SIOCSARP:          /* proxy AARP */
1784                 case SIOCDARP:          /* proxy AARP */
1785                         rtnl_lock();
1786                         rc = atif_ioctl(cmd, argp);
1787                         rtnl_unlock();
1788                         break;
1789         }
1790
1791         return rc;
1792 }
1793
1794
1795 #ifdef CONFIG_COMPAT
1796 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1797 {
1798         /*
1799          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1800          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1801          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1802          * here so there is no generic SIOCPROTOPRIVATE translation in the
1803          * system.
1804          */
1805         return -ENOIOCTLCMD;
1806 }
1807 #endif
1808
1809
1810 static struct net_proto_family atalk_family_ops = {
1811         .family         = PF_APPLETALK,
1812         .create         = atalk_create,
1813         .owner          = THIS_MODULE,
1814 };
1815
1816 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1817         .family         = PF_APPLETALK,
1818         .owner          = THIS_MODULE,
1819         .release        = atalk_release,
1820         .bind           = atalk_bind,
1821         .connect        = atalk_connect,
1822         .socketpair     = sock_no_socketpair,
1823         .accept         = sock_no_accept,
1824         .getname        = atalk_getname,
1825         .poll           = datagram_poll,
1826         .ioctl          = atalk_ioctl,
1827 #ifdef CONFIG_COMPAT
1828         .compat_ioctl   = atalk_compat_ioctl,
1829 #endif
1830         .listen         = sock_no_listen,
1831         .shutdown       = sock_no_shutdown,
1832         .setsockopt     = sock_no_setsockopt,
1833         .getsockopt     = sock_no_getsockopt,
1834         .sendmsg        = atalk_sendmsg,
1835         .recvmsg        = atalk_recvmsg,
1836         .mmap           = sock_no_mmap,
1837         .sendpage       = sock_no_sendpage,
1838 };
1839
1840 #include <linux/smp_lock.h>
1841 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1842
1843 static struct notifier_block ddp_notifier = {
1844         .notifier_call  = ddp_device_event,
1845 };
1846
1847 static struct packet_type ltalk_packet_type = {
1848         .type           = __constant_htons(ETH_P_LOCALTALK),
1849         .func           = ltalk_rcv,
1850 };
1851
1852 static struct packet_type ppptalk_packet_type = {
1853         .type           = __constant_htons(ETH_P_PPPTALK),
1854         .func           = atalk_rcv,
1855 };
1856
1857 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1858
1859 /* Export symbols for use by drivers when AppleTalk is a module */
1860 EXPORT_SYMBOL(aarp_send_ddp);
1861 EXPORT_SYMBOL(atrtr_get_dev);
1862 EXPORT_SYMBOL(atalk_find_dev_addr);
1863
1864 static char atalk_err_snap[] __initdata =
1865         KERN_CRIT "Unable to register DDP with SNAP.\n";
1866
1867 /* Called by proto.c on kernel start up */
1868 static int __init atalk_init(void)
1869 {
1870         int rc = proto_register(&ddp_proto, 0);
1871
1872         if (rc != 0)
1873                 goto out;
1874
1875         (void)sock_register(&atalk_family_ops);
1876         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1877         if (!ddp_dl)
1878                 printk(atalk_err_snap);
1879
1880         dev_add_pack(&ltalk_packet_type);
1881         dev_add_pack(&ppptalk_packet_type);
1882
1883         register_netdevice_notifier(&ddp_notifier);
1884         aarp_proto_init();
1885         atalk_proc_init();
1886         atalk_register_sysctl();
1887 out:
1888         return rc;
1889 }
1890 module_init(atalk_init);
1891
1892 /*
1893  * No explicit module reference count manipulation is needed in the
1894  * protocol. Socket layer sets module reference count for us
1895  * and interfaces reference counting is done
1896  * by the network device layer.
1897  *
1898  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1899  * sockets be closed from user space.
1900  */
1901 static void __exit atalk_exit(void)
1902 {
1903 #ifdef CONFIG_SYSCTL
1904         atalk_unregister_sysctl();
1905 #endif /* CONFIG_SYSCTL */
1906         atalk_proc_exit();
1907         aarp_cleanup_module();  /* General aarp clean-up. */
1908         unregister_netdevice_notifier(&ddp_notifier);
1909         dev_remove_pack(&ltalk_packet_type);
1910         dev_remove_pack(&ppptalk_packet_type);
1911         unregister_snap_client(ddp_dl);
1912         sock_unregister(PF_APPLETALK);
1913         proto_unregister(&ddp_proto);
1914 }
1915 module_exit(atalk_exit);
1916
1917 MODULE_LICENSE("GPL");
1918 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1919 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1920 MODULE_ALIAS_NETPROTO(PF_APPLETALK);