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                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
 181                                 (unsigned long)sk);
 182                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 183                 add_timer(&sk->sk_timer);
 184         } else
 185                 sock_put(sk);
 186 }
 187
 188 /**************************************************************************\
 189 *                                                                          *
 190 * Routing tables for the AppleTalk socket layer.                           *
 191 *                                                                          *
 192 \**************************************************************************/
 193
 194 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 195 struct atalk_route *atalk_routes;
 196 DEFINE_RWLOCK(atalk_routes_lock);
 197
 198 struct atalk_iface *atalk_interfaces;
 199 DEFINE_RWLOCK(atalk_interfaces_lock);
 200
 201 /* For probing devices or in a routerless network */
 202 struct atalk_route atrtr_default;
 203
 204 /* AppleTalk interface control */
 205 /*
 206  * Drop a device. Doesn't drop any of its routes - that is the caller's
 207  * problem. Called when we down the interface or delete the address.
 208  */
 209 static void atif_drop_device(struct net_device *dev)
 210 {
 211         struct atalk_iface **iface = &atalk_interfaces;
 212         struct atalk_iface *tmp;
 213
 214         write_lock_bh(&atalk_interfaces_lock);
 215         while ((tmp = *iface) != NULL) {
 216                 if (tmp->dev == dev) {
 217                         *iface = tmp->next;
 218                         dev_put(dev);
 219                         kfree(tmp);
 220                         dev->atalk_ptr = NULL;
 221                 } else
 222                         iface = &tmp->next;
 223         }
 224         write_unlock_bh(&atalk_interfaces_lock);
 225 }
 226
 227 static struct atalk_iface *atif_add_device(struct net_device *dev,
 228                                            struct atalk_addr *sa)
 229 {
 230         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 231
 232         if (!iface)
 233                 goto out;
 234
 235         dev_hold(dev);
 236         iface->dev = dev;
 237         dev->atalk_ptr = iface;
 238         iface->address = *sa;
 239         iface->status = 0;
 240
 241         write_lock_bh(&atalk_interfaces_lock);
 242         iface->next = atalk_interfaces;
 243         atalk_interfaces = iface;
 244         write_unlock_bh(&atalk_interfaces_lock);
 245 out:
 246         return iface;
 247 }
 248
 249 /* Perform phase 2 AARP probing on our tentative address */
 250 static int atif_probe_device(struct atalk_iface *atif)
 251 {
 252         int netrange = ntohs(atif->nets.nr_lastnet) -
 253                         ntohs(atif->nets.nr_firstnet) + 1;
 254         int probe_net = ntohs(atif->address.s_net);
 255         int probe_node = atif->address.s_node;
 256         int netct, nodect;
 257
 258         /* Offset the network we start probing with */
 259         if (probe_net == ATADDR_ANYNET) {
 260                 probe_net = ntohs(atif->nets.nr_firstnet);
 261                 if (netrange)
 262                         probe_net += jiffies % netrange;
 263         }
 264         if (probe_node == ATADDR_ANYNODE)
 265                 probe_node = jiffies & 0xFF;
 266
 267         /* Scan the networks */
 268         atif->status |= ATIF_PROBE;
 269         for (netct = 0; netct <= netrange; netct++) {
 270                 /* Sweep the available nodes from a given start */
 271                 atif->address.s_net = htons(probe_net);
 272                 for (nodect = 0; nodect < 256; nodect++) {
 273                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 274                         if (atif->address.s_node > 0 &&
 275                             atif->address.s_node < 254) {
 276                                 /* Probe a proposed address */
 277                                 aarp_probe_network(atif);
 278
 279                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 280                                         atif->status &= ~ATIF_PROBE;
 281                                         return 0;
 282                                 }
 283                         }
 284                         atif->status &= ~ATIF_PROBE_FAIL;
 285                 }
 286                 probe_net++;
 287                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 288                         probe_net = ntohs(atif->nets.nr_firstnet);
 289         }
 290         atif->status &= ~ATIF_PROBE;
 291
 292         return -EADDRINUSE;     /* Network is full... */
 293 }
 294
 295
 296 /* Perform AARP probing for a proxy address */
 297 static int atif_proxy_probe_device(struct atalk_iface *atif,
 298                                    struct atalk_addr* proxy_addr)
 299 {
 300         int netrange = ntohs(atif->nets.nr_lastnet) -
 301                         ntohs(atif->nets.nr_firstnet) + 1;
 302         /* we probe the interface's network */
 303         int probe_net = ntohs(atif->address.s_net);
 304         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 305         int netct, nodect;
 306
 307         /* Offset the network we start probing with */
 308         if (probe_net == ATADDR_ANYNET) {
 309                 probe_net = ntohs(atif->nets.nr_firstnet);
 310                 if (netrange)
 311                         probe_net += jiffies % netrange;
 312         }
 313
 314         if (probe_node == ATADDR_ANYNODE)
 315                 probe_node = jiffies & 0xFF;
 316
 317         /* Scan the networks */
 318         for (netct = 0; netct <= netrange; netct++) {
 319                 /* Sweep the available nodes from a given start */
 320                 proxy_addr->s_net = htons(probe_net);
 321                 for (nodect = 0; nodect < 256; nodect++) {
 322                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 323                         if (proxy_addr->s_node > 0 &&
 324                             proxy_addr->s_node < 254) {
 325                                 /* Tell AARP to probe a proposed address */
 326                                 int ret = aarp_proxy_probe_network(atif,
 327                                                                     proxy_addr);
 328
 329                                 if (ret != -EADDRINUSE)
 330                                         return ret;
 331                         }
 332                 }
 333                 probe_net++;
 334                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 335                         probe_net = ntohs(atif->nets.nr_firstnet);
 336         }
 337
 338         return -EADDRINUSE;     /* Network is full... */
 339 }
 340
 341
 342 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 343 {
 344         struct atalk_iface *iface = dev->atalk_ptr;
 345         return iface ? &iface->address : NULL;
 346 }
 347
 348 static struct atalk_addr *atalk_find_primary(void)
 349 {
 350         struct atalk_iface *fiface = NULL;
 351         struct atalk_addr *retval;
 352         struct atalk_iface *iface;
 353
 354         /*
 355          * Return a point-to-point interface only if
 356          * there is no non-ptp interface available.
 357          */
 358         read_lock_bh(&atalk_interfaces_lock);
 359         for (iface = atalk_interfaces; iface; iface = iface->next) {
 360                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 361                         fiface = iface;
 362                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 363                         retval = &iface->address;
 364                         goto out;
 365                 }
 366         }
 367
 368         if (fiface)
 369                 retval = &fiface->address;
 370         else if (atalk_interfaces)
 371                 retval = &atalk_interfaces->address;
 372         else
 373                 retval = NULL;
 374 out:
 375         read_unlock_bh(&atalk_interfaces_lock);
 376         return retval;
 377 }
 378
 379 /*
 380  * Find a match for 'any network' - ie any of our interfaces with that
 381  * node number will do just nicely.
 382  */
 383 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 384 {
 385         struct atalk_iface *iface = dev->atalk_ptr;
 386
 387         if (!iface || iface->status & ATIF_PROBE)
 388                 goto out_err;
 389
 390         if (node != ATADDR_BCAST &&
 391             iface->address.s_node != node &&
 392             node != ATADDR_ANYNODE)
 393                 goto out_err;
 394 out:
 395         return iface;
 396 out_err:
 397         iface = NULL;
 398         goto out;
 399 }
 400
 401 /* Find a match for a specific network:node pair */
 402 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 403 {
 404         struct atalk_iface *iface;
 405
 406         read_lock_bh(&atalk_interfaces_lock);
 407         for (iface = atalk_interfaces; iface; iface = iface->next) {
 408                 if ((node == ATADDR_BCAST ||
 409                      node == ATADDR_ANYNODE ||
 410                      iface->address.s_node == node) &&
 411                     iface->address.s_net == net &&
 412                     !(iface->status & ATIF_PROBE))
 413                         break;
 414
 415                 /* XXXX.0 -- net.0 returns the iface associated with net */
 416                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 417                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 418                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 419                         break;
 420         }
 421         read_unlock_bh(&atalk_interfaces_lock);
 422         return iface;
 423 }
 424
 425
 426 /*
 427  * Find a route for an AppleTalk packet. This ought to get cached in
 428  * the socket (later on...). We know about host routes and the fact
 429  * that a route must be direct to broadcast.
 430  */
 431 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 432 {
 433         /*
 434          * we must search through all routes unless we find a
 435          * host route, because some host routes might overlap
 436          * network routes
 437          */
 438         struct atalk_route *net_route = NULL;
 439         struct atalk_route *r;
 440
 441         read_lock_bh(&atalk_routes_lock);
 442         for (r = atalk_routes; r; r = r->next) {
 443                 if (!(r->flags & RTF_UP))
 444                         continue;
 445
 446                 if (r->target.s_net == target->s_net) {
 447                         if (r->flags & RTF_HOST) {
 448                                 /*
 449                                  * if this host route is for the target,
 450                                  * the we're done
 451                                  */
 452                                 if (r->target.s_node == target->s_node)
 453                                         goto out;
 454                         } else
 455                                 /*
 456                                  * this route will work if there isn't a
 457                                  * direct host route, so cache it
 458                                  */
 459                                 net_route = r;
 460                 }
 461         }
 462
 463         /*
 464          * if we found a network route but not a direct host
 465          * route, then return it
 466          */
 467         if (net_route)
 468                 r = net_route;
 469         else if (atrtr_default.dev)
 470                 r = &atrtr_default;
 471         else /* No route can be found */
 472                 r = NULL;
 473 out:
 474         read_unlock_bh(&atalk_routes_lock);
 475         return r;
 476 }
 477
 478
 479 /*
 480  * Given an AppleTalk network, find the device to use. This can be
 481  * a simple lookup.
 482  */
 483 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 484 {
 485         struct atalk_route *atr = atrtr_find(sa);
 486         return atr ? atr->dev : NULL;
 487 }
 488
 489 /* Set up a default router */
 490 static void atrtr_set_default(struct net_device *dev)
 491 {
 492         atrtr_default.dev            = dev;
 493         atrtr_default.flags          = RTF_UP;
 494         atrtr_default.gateway.s_net  = htons(0);
 495         atrtr_default.gateway.s_node = 0;
 496 }
 497
 498 /*
 499  * Add a router. Basically make sure it looks valid and stuff the
 500  * entry in the list. While it uses netranges we always set them to one
 501  * entry to work like netatalk.
 502  */
 503 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 504 {
 505         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 506         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 507         struct atalk_route *rt;
 508         struct atalk_iface *iface, *riface;
 509         int retval = -EINVAL;
 510
 511         /*
 512          * Fixme: Raise/Lower a routing change semaphore for these
 513          * operations.
 514          */
 515
 516         /* Validate the request */
 517         if (ta->sat_family != AF_APPLETALK ||
 518             (!devhint && ga->sat_family != AF_APPLETALK))
 519                 goto out;
 520
 521         /* Now walk the routing table and make our decisions */
 522         write_lock_bh(&atalk_routes_lock);
 523         for (rt = atalk_routes; rt; rt = rt->next) {
 524                 if (r->rt_flags != rt->flags)
 525                         continue;
 526
 527                 if (ta->sat_addr.s_net == rt->target.s_net) {
 528                         if (!(rt->flags & RTF_HOST))
 529                                 break;
 530                         if (ta->sat_addr.s_node == rt->target.s_node)
 531                                 break;
 532                 }
 533         }
 534
 535         if (!devhint) {
 536                 riface = NULL;
 537
 538                 read_lock_bh(&atalk_interfaces_lock);
 539                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 540                         if (!riface &&
 541                             ntohs(ga->sat_addr.s_net) >=
 542                                         ntohs(iface->nets.nr_firstnet) &&
 543                             ntohs(ga->sat_addr.s_net) <=
 544                                         ntohs(iface->nets.nr_lastnet))
 545                                 riface = iface;
 546
 547                         if (ga->sat_addr.s_net == iface->address.s_net &&
 548                             ga->sat_addr.s_node == iface->address.s_node)
 549                                 riface = iface;
 550                 }
 551                 read_unlock_bh(&atalk_interfaces_lock);
 552
 553                 retval = -ENETUNREACH;
 554                 if (!riface)
 555                         goto out_unlock;
 556
 557                 devhint = riface->dev;
 558         }
 559
 560         if (!rt) {
 561                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 562
 563                 retval = -ENOBUFS;
 564                 if (!rt)
 565                         goto out_unlock;
 566
 567                 rt->next = atalk_routes;
 568                 atalk_routes = rt;
 569         }
 570
 571         /* Fill in the routing entry */
 572         rt->target  = ta->sat_addr;
 573         dev_hold(devhint);
 574         rt->dev     = devhint;
 575         rt->flags   = r->rt_flags;
 576         rt->gateway = ga->sat_addr;
 577
 578         retval = 0;
 579 out_unlock:
 580         write_unlock_bh(&atalk_routes_lock);
 581 out:
 582         return retval;
 583 }
 584
 585 /* Delete a route. Find it and discard it */
 586 static int atrtr_delete(struct atalk_addr * addr)
 587 {
 588         struct atalk_route **r = &atalk_routes;
 589         int retval = 0;
 590         struct atalk_route *tmp;
 591
 592         write_lock_bh(&atalk_routes_lock);
 593         while ((tmp = *r) != NULL) {
 594                 if (tmp->target.s_net == addr->s_net &&
 595                     (!(tmp->flags&RTF_GATEWAY) ||
 596                      tmp->target.s_node == addr->s_node)) {
 597                         *r = tmp->next;
 598                         dev_put(tmp->dev);
 599                         kfree(tmp);
 600                         goto out;
 601                 }
 602                 r = &tmp->next;
 603         }
 604         retval = -ENOENT;
 605 out:
 606         write_unlock_bh(&atalk_routes_lock);
 607         return retval;
 608 }
 609
 610 /*
 611  * Called when a device is downed. Just throw away any routes
 612  * via it.
 613  */
 614 static void atrtr_device_down(struct net_device *dev)
 615 {
 616         struct atalk_route **r = &atalk_routes;
 617         struct atalk_route *tmp;
 618
 619         write_lock_bh(&atalk_routes_lock);
 620         while ((tmp = *r) != NULL) {
 621                 if (tmp->dev == dev) {
 622                         *r = tmp->next;
 623                         dev_put(dev);
 624                         kfree(tmp);
 625                 } else
 626                         r = &tmp->next;
 627         }
 628         write_unlock_bh(&atalk_routes_lock);
 629
 630         if (atrtr_default.dev == dev)
 631                 atrtr_set_default(NULL);
 632 }
 633
 634 /* Actually down the interface */
 635 static inline void atalk_dev_down(struct net_device *dev)
 636 {
 637         atrtr_device_down(dev); /* Remove all routes for the device */
 638         aarp_device_down(dev);  /* Remove AARP entries for the device */
 639         atif_drop_device(dev);  /* Remove the device */
 640 }
 641
 642 /*
 643  * A device event has occurred. Watch for devices going down and
 644  * delete our use of them (iface and route).
 645  */
 646 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 647                             void *ptr)
 648 {
 649         struct net_device *dev = ptr;
 650
 651         if (dev_net(dev) != &init_net)
 652                 return NOTIFY_DONE;
 653
 654         if (event == NETDEV_DOWN)
 655                 /* Discard any use of this */
 656                 atalk_dev_down(dev);
 657
 658         return NOTIFY_DONE;
 659 }
 660
 661 /* ioctl calls. Shouldn't even need touching */
 662 /* Device configuration ioctl calls */
 663 static int atif_ioctl(int cmd, void __user *arg)
 664 {
 665         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 666         struct ifreq atreq;
 667         struct atalk_netrange *nr;
 668         struct sockaddr_at *sa;
 669         struct net_device *dev;
 670         struct atalk_iface *atif;
 671         int ct;
 672         int limit;
 673         struct rtentry rtdef;
 674         int add_route;
 675
 676         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 677                 return -EFAULT;
 678
 679         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
 680         if (!dev)
 681                 return -ENODEV;
 682
 683         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 684         atif = atalk_find_dev(dev);
 685
 686         switch (cmd) {
 687                 case SIOCSIFADDR:
 688                         if (!capable(CAP_NET_ADMIN))
 689                                 return -EPERM;
 690                         if (sa->sat_family != AF_APPLETALK)
 691                                 return -EINVAL;
 692                         if (dev->type != ARPHRD_ETHER &&
 693                             dev->type != ARPHRD_LOOPBACK &&
 694                             dev->type != ARPHRD_LOCALTLK &&
 695                             dev->type != ARPHRD_PPP)
 696                                 return -EPROTONOSUPPORT;
 697
 698                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 699                         add_route = 1;
 700
 701                         /*
 702                          * if this is a point-to-point iface, and we already
 703                          * have an iface for this AppleTalk address, then we
 704                          * should not add a route
 705                          */
 706                         if ((dev->flags & IFF_POINTOPOINT) &&
 707                             atalk_find_interface(sa->sat_addr.s_net,
 708                                                  sa->sat_addr.s_node)) {
 709                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 710                                                   "interface added with "
 711                                                   "existing address\n");
 712                                 add_route = 0;
 713                         }
 714
 715                         /*
 716                          * Phase 1 is fine on LocalTalk but we don't do
 717                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 718                          */
 719                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 720                                 return -EPROTONOSUPPORT;
 721                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 722                             sa->sat_addr.s_node == 254)
 723                                 return -EINVAL;
 724                         if (atif) {
 725                                 /* Already setting address */
 726                                 if (atif->status & ATIF_PROBE)
 727                                         return -EBUSY;
 728
 729                                 atif->address.s_net  = sa->sat_addr.s_net;
 730                                 atif->address.s_node = sa->sat_addr.s_node;
 731                                 atrtr_device_down(dev); /* Flush old routes */
 732                         } else {
 733                                 atif = atif_add_device(dev, &sa->sat_addr);
 734                                 if (!atif)
 735                                         return -ENOMEM;
 736                         }
 737                         atif->nets = *nr;
 738
 739                         /*
 740                          * Check if the chosen address is used. If so we
 741                          * error and atalkd will try another.
 742                          */
 743
 744                         if (!(dev->flags & IFF_LOOPBACK) &&
 745                             !(dev->flags & IFF_POINTOPOINT) &&
 746                             atif_probe_device(atif) < 0) {
 747                                 atif_drop_device(dev);
 748                                 return -EADDRINUSE;
 749                         }
 750
 751                         /* Hey it worked - add the direct routes */
 752                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 753                         sa->sat_family = AF_APPLETALK;
 754                         sa->sat_addr.s_net  = atif->address.s_net;
 755                         sa->sat_addr.s_node = atif->address.s_node;
 756                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 757                         rtdef.rt_flags = RTF_UP;
 758                         sa->sat_family = AF_APPLETALK;
 759                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 760                         if (dev->flags & IFF_LOOPBACK ||
 761                             dev->flags & IFF_POINTOPOINT)
 762                                 rtdef.rt_flags |= RTF_HOST;
 763
 764                         /* Routerless initial state */
 765                         if (nr->nr_firstnet == htons(0) &&
 766                             nr->nr_lastnet == htons(0xFFFE)) {
 767                                 sa->sat_addr.s_net = atif->address.s_net;
 768                                 atrtr_create(&rtdef, dev);
 769                                 atrtr_set_default(dev);
 770                         } else {
 771                                 limit = ntohs(nr->nr_lastnet);
 772                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 773                                         printk(KERN_WARNING "Too many routes/"
 774                                                             "iface.\n");
 775                                         return -EINVAL;
 776                                 }
 777                                 if (add_route)
 778                                         for (ct = ntohs(nr->nr_firstnet);
 779                                              ct <= limit; ct++) {
 780                                                 sa->sat_addr.s_net = htons(ct);
 781                                                 atrtr_create(&rtdef, dev);
 782                                         }
 783                         }
 784                         dev_mc_add(dev, aarp_mcast, 6, 1);
 785                         return 0;
 786
 787                 case SIOCGIFADDR:
 788                         if (!atif)
 789                                 return -EADDRNOTAVAIL;
 790
 791                         sa->sat_family = AF_APPLETALK;
 792                         sa->sat_addr = atif->address;
 793                         break;
 794
 795                 case SIOCGIFBRDADDR:
 796                         if (!atif)
 797                                 return -EADDRNOTAVAIL;
 798
 799                         sa->sat_family = AF_APPLETALK;
 800                         sa->sat_addr.s_net = atif->address.s_net;
 801                         sa->sat_addr.s_node = ATADDR_BCAST;
 802                         break;
 803
 804                 case SIOCATALKDIFADDR:
 805                 case SIOCDIFADDR:
 806                         if (!capable(CAP_NET_ADMIN))
 807                                 return -EPERM;
 808                         if (sa->sat_family != AF_APPLETALK)
 809                                 return -EINVAL;
 810                         atalk_dev_down(dev);
 811                         break;
 812
 813                 case SIOCSARP:
 814                         if (!capable(CAP_NET_ADMIN))
 815                                 return -EPERM;
 816                         if (sa->sat_family != AF_APPLETALK)
 817                                 return -EINVAL;
 818                         if (!atif)
 819                                 return -EADDRNOTAVAIL;
 820
 821                         /*
 822                          * for now, we only support proxy AARP on ELAP;
 823                          * we should be able to do it for LocalTalk, too.
 824                          */
 825                         if (dev->type != ARPHRD_ETHER)
 826                                 return -EPROTONOSUPPORT;
 827
 828                         /*
 829                          * atif points to the current interface on this network;
 830                          * we aren't concerned about its current status (at
 831                          * least for now), but it has all the settings about
 832                          * the network we're going to probe. Consequently, it
 833                          * must exist.
 834                          */
 835                         if (!atif)
 836                                 return -EADDRNOTAVAIL;
 837
 838                         nr = (struct atalk_netrange *)&(atif->nets);
 839                         /*
 840                          * Phase 1 is fine on Localtalk but we don't do
 841                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 842                          */
 843                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 844                                 return -EPROTONOSUPPORT;
 845
 846                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 847                             sa->sat_addr.s_node == 254)
 848                                 return -EINVAL;
 849
 850                         /*
 851                          * Check if the chosen address is used. If so we
 852                          * error and ATCP will try another.
 853                          */
 854                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 855                                 return -EADDRINUSE;
 856
 857                         /*
 858                          * We now have an address on the local network, and
 859                          * the AARP code will defend it for us until we take it
 860                          * down. We don't set up any routes right now, because
 861                          * ATCP will install them manually via SIOCADDRT.
 862                          */
 863                         break;
 864
 865                 case SIOCDARP:
 866                         if (!capable(CAP_NET_ADMIN))
 867                                 return -EPERM;
 868                         if (sa->sat_family != AF_APPLETALK)
 869                                 return -EINVAL;
 870                         if (!atif)
 871                                 return -EADDRNOTAVAIL;
 872
 873                         /* give to aarp module to remove proxy entry */
 874                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 875                         return 0;
 876         }
 877
 878         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 879 }
 880
 881 /* Routing ioctl() calls */
 882 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 883 {
 884         struct rtentry rt;
 885
 886         if (copy_from_user(&rt, arg, sizeof(rt)))
 887                 return -EFAULT;
 888
 889         switch (cmd) {
 890                 case SIOCDELRT:
 891                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 892                                 return -EINVAL;
 893                         return atrtr_delete(&((struct sockaddr_at *)
 894                                                 &rt.rt_dst)->sat_addr);
 895
 896                 case SIOCADDRT: {
 897                         struct net_device *dev = NULL;
 898                         if (rt.rt_dev) {
 899                                 char name[IFNAMSIZ];
 900                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 901                                         return -EFAULT;
 902                                 name[IFNAMSIZ-1] = '\0';
 903                                 dev = __dev_get_by_name(&init_net, name);
 904                                 if (!dev)
 905                                         return -ENODEV;
 906                         }
 907                         return atrtr_create(&rt, dev);
 908                 }
 909         }
 910         return -EINVAL;
 911 }
 912
 913 /**************************************************************************\
 914 *                                                                          *
 915 * Handling for system calls applied via the various interfaces to an       *
 916 * AppleTalk socket object.                                                 *
 917 *                                                                          *
 918 \**************************************************************************/
 919
 920 /*
 921  * Checksum: This is 'optional'. It's quite likely also a good
 922  * candidate for assembler hackery 8)
 923  */
 924 static unsigned long atalk_sum_partial(const unsigned char *data,
 925                                        int len, unsigned long sum)
 926 {
 927         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 928         while (len--) {
 929                 sum += *data;
 930                 sum <<= 1;
 931                 if (sum & 0x10000) {
 932                         sum++;
 933                         sum &= 0xffff;
 934                 }
 935                 data++;
 936         }
 937         return sum;
 938 }
 939
 940 /*  Checksum skb data --  similar to skb_checksum  */
 941 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 942                                    int len, unsigned long sum)
 943 {
 944         int start = skb_headlen(skb);
 945         int i, copy;
 946
 947         /* checksum stuff in header space */
 948         if ( (copy = start - offset) > 0) {
 949                 if (copy > len)
 950                         copy = len;
 951                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 952                 if ( (len -= copy) == 0)
 953                         return sum;
 954
 955                 offset += copy;
 956         }
 957
 958         /* checksum stuff in frags */
 959         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 960                 int end;
 961
 962                 BUG_TRAP(start <= offset + len);
 963
 964                 end = start + skb_shinfo(skb)->frags[i].size;
 965                 if ((copy = end - offset) > 0) {
 966                         u8 *vaddr;
 967                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 968
 969                         if (copy > len)
 970                                 copy = len;
 971                         vaddr = kmap_skb_frag(frag);
 972                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 973                                                   offset - start, copy, sum);
 974                         kunmap_skb_frag(vaddr);
 975
 976                         if (!(len -= copy))
 977                                 return sum;
 978                         offset += copy;
 979                 }
 980                 start = end;
 981         }
 982
 983         if (skb_shinfo(skb)->frag_list) {
 984                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
 985
 986                 for (; list; list = list->next) {
 987                         int end;
 988
 989                         BUG_TRAP(start <= offset + len);
 990
 991                         end = start + list->len;
 992                         if ((copy = end - offset) > 0) {
 993                                 if (copy > len)
 994                                         copy = len;
 995                                 sum = atalk_sum_skb(list, offset - start,
 996                                                     copy, sum);
 997                                 if ((len -= copy) == 0)
 998                                         return sum;
 999                                 offset += copy;
1000                         }
1001                         start = end;
1002                 }
1003         }
1004
1005         BUG_ON(len > 0);
1006
1007         return sum;
1008 }
1009
1010 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1011 {
1012         unsigned long sum;
1013
1014         /* skip header 4 bytes */
1015         sum = atalk_sum_skb(skb, 4, len-4, 0);
1016
1017         /* Use 0xFFFF for 0. 0 itself means none */
1018         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1019 }
1020
1021 static struct proto ddp_proto = {
1022         .name     = "DDP",
1023         .owner    = THIS_MODULE,
1024         .obj_size = sizeof(struct atalk_sock),
1025 };
1026
1027 /*
1028  * Create a socket. Initialise the socket, blank the addresses
1029  * set the state.
1030  */
1031 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1032 {
1033         struct sock *sk;
1034         int rc = -ESOCKTNOSUPPORT;
1035
1036         if (net != &init_net)
1037                 return -EAFNOSUPPORT;
1038
1039         /*
1040          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1041          * and gives you the full ELAP frame. Should be handy for CAP 8)
1042          */
1043         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1044                 goto out;
1045         rc = -ENOMEM;
1046         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1047         if (!sk)
1048                 goto out;
1049         rc = 0;
1050         sock->ops = &atalk_dgram_ops;
1051         sock_init_data(sock, sk);
1052
1053         /* Checksums on by default */
1054         sock_set_flag(sk, SOCK_ZAPPED);
1055 out:
1056         return rc;
1057 }
1058
1059 /* Free a socket. No work needed */
1060 static int atalk_release(struct socket *sock)
1061 {
1062         struct sock *sk = sock->sk;
1063
1064         if (sk) {
1065                 sock_orphan(sk);
1066                 sock->sk = NULL;
1067                 atalk_destroy_socket(sk);
1068         }
1069         return 0;
1070 }
1071
1072 /**
1073  * atalk_pick_and_bind_port - Pick a source port when one is not given
1074  * @sk - socket to insert into the tables
1075  * @sat - address to search for
1076  *
1077  * Pick a source port when one is not given. If we can find a suitable free
1078  * one, we insert the socket into the tables using it.
1079  *
1080  * This whole operation must be atomic.
1081  */
1082 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1083 {
1084         int retval;
1085
1086         write_lock_bh(&atalk_sockets_lock);
1087
1088         for (sat->sat_port = ATPORT_RESERVED;
1089              sat->sat_port < ATPORT_LAST;
1090              sat->sat_port++) {
1091                 struct sock *s;
1092                 struct hlist_node *node;
1093
1094                 sk_for_each(s, node, &atalk_sockets) {
1095                         struct atalk_sock *at = at_sk(s);
1096
1097                         if (at->src_net == sat->sat_addr.s_net &&
1098                             at->src_node == sat->sat_addr.s_node &&
1099                             at->src_port == sat->sat_port)
1100                                 goto try_next_port;
1101                 }
1102
1103                 /* Wheee, it's free, assign and insert. */
1104                 __atalk_insert_socket(sk);
1105                 at_sk(sk)->src_port = sat->sat_port;
1106                 retval = 0;
1107                 goto out;
1108
1109 try_next_port:;
1110         }
1111
1112         retval = -EBUSY;
1113 out:
1114         write_unlock_bh(&atalk_sockets_lock);
1115         return retval;
1116 }
1117
1118 static int atalk_autobind(struct sock *sk)
1119 {
1120         struct atalk_sock *at = at_sk(sk);
1121         struct sockaddr_at sat;
1122         struct atalk_addr *ap = atalk_find_primary();
1123         int n = -EADDRNOTAVAIL;
1124
1125         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1126                 goto out;
1127
1128         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1129         at->src_node = sat.sat_addr.s_node = ap->s_node;
1130
1131         n = atalk_pick_and_bind_port(sk, &sat);
1132         if (!n)
1133                 sock_reset_flag(sk, SOCK_ZAPPED);
1134 out:
1135         return n;
1136 }
1137
1138 /* Set the address 'our end' of the connection */
1139 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1140 {
1141         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1142         struct sock *sk = sock->sk;
1143         struct atalk_sock *at = at_sk(sk);
1144
1145         if (!sock_flag(sk, SOCK_ZAPPED) ||
1146             addr_len != sizeof(struct sockaddr_at))
1147                 return -EINVAL;
1148
1149         if (addr->sat_family != AF_APPLETALK)
1150                 return -EAFNOSUPPORT;
1151
1152         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1153                 struct atalk_addr *ap = atalk_find_primary();
1154
1155                 if (!ap)
1156                         return -EADDRNOTAVAIL;
1157
1158                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1159                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1160         } else {
1161                 if (!atalk_find_interface(addr->sat_addr.s_net,
1162                                           addr->sat_addr.s_node))
1163                         return -EADDRNOTAVAIL;
1164
1165                 at->src_net  = addr->sat_addr.s_net;
1166                 at->src_node = addr->sat_addr.s_node;
1167         }
1168
1169         if (addr->sat_port == ATADDR_ANYPORT) {
1170                 int n = atalk_pick_and_bind_port(sk, addr);
1171
1172                 if (n < 0)
1173                         return n;
1174         } else {
1175                 at->src_port = addr->sat_port;
1176
1177                 if (atalk_find_or_insert_socket(sk, addr))
1178                         return -EADDRINUSE;
1179         }
1180
1181         sock_reset_flag(sk, SOCK_ZAPPED);
1182         return 0;
1183 }
1184
1185 /* Set the address we talk to */
1186 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1187                          int addr_len, int flags)
1188 {
1189         struct sock *sk = sock->sk;
1190         struct atalk_sock *at = at_sk(sk);
1191         struct sockaddr_at *addr;
1192
1193         sk->sk_state   = TCP_CLOSE;
1194         sock->state = SS_UNCONNECTED;
1195
1196         if (addr_len != sizeof(*addr))
1197                 return -EINVAL;
1198
1199         addr = (struct sockaddr_at *)uaddr;
1200
1201         if (addr->sat_family != AF_APPLETALK)
1202                 return -EAFNOSUPPORT;
1203
1204         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1205             !sock_flag(sk, SOCK_BROADCAST)) {
1206 #if 1
1207                 printk(KERN_WARNING "%s is broken and did not set "
1208                                     "SO_BROADCAST. It will break when 2.2 is "
1209                                     "released.\n",
1210                         current->comm);
1211 #else
1212                 return -EACCES;
1213 #endif
1214         }
1215
1216         if (sock_flag(sk, SOCK_ZAPPED))
1217                 if (atalk_autobind(sk) < 0)
1218                         return -EBUSY;
1219
1220         if (!atrtr_get_dev(&addr->sat_addr))
1221                 return -ENETUNREACH;
1222
1223         at->dest_port = addr->sat_port;
1224         at->dest_net  = addr->sat_addr.s_net;
1225         at->dest_node = addr->sat_addr.s_node;
1226
1227         sock->state  = SS_CONNECTED;
1228         sk->sk_state = TCP_ESTABLISHED;
1229         return 0;
1230 }
1231
1232 /*
1233  * Find the name of an AppleTalk socket. Just copy the right
1234  * fields into the sockaddr.
1235  */
1236 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1237                          int *uaddr_len, int peer)
1238 {
1239         struct sockaddr_at sat;
1240         struct sock *sk = sock->sk;
1241         struct atalk_sock *at = at_sk(sk);
1242
1243         if (sock_flag(sk, SOCK_ZAPPED))
1244                 if (atalk_autobind(sk) < 0)
1245                         return -ENOBUFS;
1246
1247         *uaddr_len = sizeof(struct sockaddr_at);
1248
1249         if (peer) {
1250                 if (sk->sk_state != TCP_ESTABLISHED)
1251                         return -ENOTCONN;
1252
1253                 sat.sat_addr.s_net  = at->dest_net;
1254                 sat.sat_addr.s_node = at->dest_node;
1255                 sat.sat_port        = at->dest_port;
1256         } else {
1257                 sat.sat_addr.s_net  = at->src_net;
1258                 sat.sat_addr.s_node = at->src_node;
1259                 sat.sat_port        = at->src_port;
1260         }
1261
1262         sat.sat_family = AF_APPLETALK;
1263         memcpy(uaddr, &sat, sizeof(sat));
1264         return 0;
1265 }
1266
1267 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1268 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1269 {
1270         return skb->data[12] == 22;
1271 }
1272
1273 static int handle_ip_over_ddp(struct sk_buff *skb)
1274 {
1275         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1276         struct net_device_stats *stats;
1277
1278         /* This needs to be able to handle ipddp"N" devices */
1279         if (!dev)
1280                 return -ENODEV;
1281
1282         skb->protocol = htons(ETH_P_IP);
1283         skb_pull(skb, 13);
1284         skb->dev   = dev;
1285         skb_reset_transport_header(skb);
1286
1287         stats = dev->priv;
1288         stats->rx_packets++;
1289         stats->rx_bytes += skb->len + 13;
1290         netif_rx(skb);  /* Send the SKB up to a higher place. */
1291         return 0;
1292 }
1293 #else
1294 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1295 #define is_ip_over_ddp(skb) 0
1296 #define handle_ip_over_ddp(skb) 0
1297 #endif
1298
1299 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1300                                struct ddpehdr *ddp, __u16 len_hops,
1301                                int origlen)
1302 {
1303         struct atalk_route *rt;
1304         struct atalk_addr ta;
1305
1306         /*
1307          * Don't route multicast, etc., packets, or packets sent to "this
1308          * network"
1309          */
1310         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1311                 /*
1312                  * FIXME:
1313                  *
1314                  * Can it ever happen that a packet is from a PPP iface and
1315                  * needs to be broadcast onto the default network?
1316                  */
1317                 if (dev->type == ARPHRD_PPP)
1318                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1319                                           "packet received from PPP iface\n");
1320                 goto free_it;
1321         }
1322
1323         ta.s_net  = ddp->deh_dnet;
1324         ta.s_node = ddp->deh_dnode;
1325
1326         /* Route the packet */
1327         rt = atrtr_find(&ta);
1328         /* increment hops count */
1329         len_hops += 1 << 10;
1330         if (!rt || !(len_hops & (15 << 10)))
1331                 goto free_it;
1332
1333         /* FIXME: use skb->cb to be able to use shared skbs */
1334
1335         /*
1336          * Route goes through another gateway, so set the target to the
1337          * gateway instead.
1338          */
1339
1340         if (rt->flags & RTF_GATEWAY) {
1341                 ta.s_net  = rt->gateway.s_net;
1342                 ta.s_node = rt->gateway.s_node;
1343         }
1344
1345         /* Fix up skb->len field */
1346         skb_trim(skb, min_t(unsigned int, origlen,
1347                             (rt->dev->hard_header_len +
1348                              ddp_dl->header_length + (len_hops & 1023))));
1349
1350         /* FIXME: use skb->cb to be able to use shared skbs */
1351         ddp->deh_len_hops = htons(len_hops);
1352
1353         /*
1354          * Send the buffer onwards
1355          *
1356          * Now we must always be careful. If it's come from LocalTalk to
1357          * EtherTalk it might not fit
1358          *
1359          * Order matters here: If a packet has to be copied to make a new
1360          * headroom (rare hopefully) then it won't need unsharing.
1361          *
1362          * Note. ddp-> becomes invalid at the realloc.
1363          */
1364         if (skb_headroom(skb) < 22) {
1365                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1366                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1367                 kfree_skb(skb);
1368                 if (!nskb)
1369                         goto out;
1370                 skb = nskb;
1371         } else
1372                 skb = skb_unshare(skb, GFP_ATOMIC);
1373
1374         /*
1375          * If the buffer didn't vanish into the lack of space bitbucket we can
1376          * send it.
1377          */
1378         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1379                 goto free_it;
1380 out:
1381         return;
1382 free_it:
1383         kfree_skb(skb);
1384 }
1385
1386 /**
1387  *      atalk_rcv - Receive a packet (in skb) from device dev
1388  *      @skb - packet received
1389  *      @dev - network device where the packet comes from
1390  *      @pt - packet type
1391  *
1392  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1393  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1394  *      is the DDP header, skb->len is the DDP length. The physical headers
1395  *      have been extracted. PPP should probably pass frames marked as for this
1396  *      layer.  [ie ARPHRD_ETHERTALK]
1397  */
1398 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1399                      struct packet_type *pt, struct net_device *orig_dev)
1400 {
1401         struct ddpehdr *ddp;
1402         struct sock *sock;
1403         struct atalk_iface *atif;
1404         struct sockaddr_at tosat;
1405         int origlen;
1406         __u16 len_hops;
1407
1408         if (dev_net(dev) != &init_net)
1409                 goto freeit;
1410
1411         /* Don't mangle buffer if shared */
1412         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1413                 goto out;
1414
1415         /* Size check and make sure header is contiguous */
1416         if (!pskb_may_pull(skb, sizeof(*ddp)))
1417                 goto freeit;
1418
1419         ddp = ddp_hdr(skb);
1420
1421         len_hops = ntohs(ddp->deh_len_hops);
1422
1423         /* Trim buffer in case of stray trailing data */
1424         origlen = skb->len;
1425         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1426
1427         /*
1428          * Size check to see if ddp->deh_len was crap
1429          * (Otherwise we'll detonate most spectacularly
1430          * in the middle of atalk_checksum() or recvmsg()).
1431          */
1432         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1433                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1434                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1435                 goto freeit;
1436         }
1437
1438         /*
1439          * Any checksums. Note we don't do htons() on this == is assumed to be
1440          * valid for net byte orders all over the networking code...
1441          */
1442         if (ddp->deh_sum &&
1443             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1444                 /* Not a valid AppleTalk frame - dustbin time */
1445                 goto freeit;
1446
1447         /* Check the packet is aimed at us */
1448         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1449                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1450         else
1451                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1452
1453         if (!atif) {
1454                 /* Not ours, so we route the packet via the correct
1455                  * AppleTalk iface
1456                  */
1457                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1458                 goto out;
1459         }
1460
1461         /* if IP over DDP is not selected this code will be optimized out */
1462         if (is_ip_over_ddp(skb))
1463                 return handle_ip_over_ddp(skb);
1464         /*
1465          * Which socket - atalk_search_socket() looks for a *full match*
1466          * of the <net, node, port> tuple.
1467          */
1468         tosat.sat_addr.s_net  = ddp->deh_dnet;
1469         tosat.sat_addr.s_node = ddp->deh_dnode;
1470         tosat.sat_port        = ddp->deh_dport;
1471
1472         sock = atalk_search_socket(&tosat, atif);
1473         if (!sock) /* But not one of our sockets */
1474                 goto freeit;
1475
1476         /* Queue packet (standard) */
1477         skb->sk = sock;
1478
1479         if (sock_queue_rcv_skb(sock, skb) < 0)
1480                 goto freeit;
1481 out:
1482         return 0;
1483 freeit:
1484         kfree_skb(skb);
1485         goto out;
1486 }
1487
1488 /*
1489  * Receive a LocalTalk frame. We make some demands on the caller here.
1490  * Caller must provide enough headroom on the packet to pull the short
1491  * header and append a long one.
1492  */
1493 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1494                      struct packet_type *pt, struct net_device *orig_dev)
1495 {
1496         if (dev_net(dev) != &init_net)
1497                 goto freeit;
1498
1499         /* Expand any short form frames */
1500         if (skb_mac_header(skb)[2] == 1) {
1501                 struct ddpehdr *ddp;
1502                 /* Find our address */
1503                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1504
1505                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1506                         goto freeit;
1507
1508                 /* Don't mangle buffer if shared */
1509                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1510                         return 0;
1511
1512                 /*
1513                  * The push leaves us with a ddephdr not an shdr, and
1514                  * handily the port bytes in the right place preset.
1515                  */
1516                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1517
1518                 /* Now fill in the long header */
1519
1520                 /*
1521                  * These two first. The mac overlays the new source/dest
1522                  * network information so we MUST copy these before
1523                  * we write the network numbers !
1524                  */
1525
1526                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1527                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1528
1529                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1530                 ddp->deh_snet  = ap->s_net;
1531                 ddp->deh_sum   = 0;             /* No checksum */
1532                 /*
1533                  * Not sure about this bit...
1534                  */
1535                 /* Non routable, so force a drop if we slip up later */
1536                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1537         }
1538         skb_reset_transport_header(skb);
1539
1540         return atalk_rcv(skb, dev, pt, orig_dev);
1541 freeit:
1542         kfree_skb(skb);
1543         return 0;
1544 }
1545
1546 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1547                          size_t len)
1548 {
1549         struct sock *sk = sock->sk;
1550         struct atalk_sock *at = at_sk(sk);
1551         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1552         int flags = msg->msg_flags;
1553         int loopback = 0;
1554         struct sockaddr_at local_satalk, gsat;
1555         struct sk_buff *skb;
1556         struct net_device *dev;
1557         struct ddpehdr *ddp;
1558         int size;
1559         struct atalk_route *rt;
1560         int err;
1561
1562         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1563                 return -EINVAL;
1564
1565         if (len > DDP_MAXSZ)
1566                 return -EMSGSIZE;
1567
1568         if (usat) {
1569                 if (sock_flag(sk, SOCK_ZAPPED))
1570                         if (atalk_autobind(sk) < 0)
1571                                 return -EBUSY;
1572
1573                 if (msg->msg_namelen < sizeof(*usat) ||
1574                     usat->sat_family != AF_APPLETALK)
1575                         return -EINVAL;
1576
1577                 /* netatalk doesn't implement this check */
1578                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1579                     !sock_flag(sk, SOCK_BROADCAST)) {
1580                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1581                                          "it will break before 2.2\n");
1582 #if 0
1583                         return -EPERM;
1584 #endif
1585                 }
1586         } else {
1587                 if (sk->sk_state != TCP_ESTABLISHED)
1588                         return -ENOTCONN;
1589                 usat = &local_satalk;
1590                 usat->sat_family      = AF_APPLETALK;
1591                 usat->sat_port        = at->dest_port;
1592                 usat->sat_addr.s_node = at->dest_node;
1593                 usat->sat_addr.s_net  = at->dest_net;
1594         }
1595
1596         /* Build a packet */
1597         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1598
1599         /* For headers */
1600         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1601
1602         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1603                 rt = atrtr_find(&usat->sat_addr);
1604         } else {
1605                 struct atalk_addr at_hint;
1606
1607                 at_hint.s_node = 0;
1608                 at_hint.s_net  = at->src_net;
1609
1610                 rt = atrtr_find(&at_hint);
1611         }
1612         if (!rt)
1613                 return -ENETUNREACH;
1614
1615         dev = rt->dev;
1616
1617         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1618                         sk, size, dev->name);
1619
1620         size += dev->hard_header_len;
1621         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1622         if (!skb)
1623                 return err;
1624
1625         skb->sk = sk;
1626         skb_reserve(skb, ddp_dl->header_length);
1627         skb_reserve(skb, dev->hard_header_len);
1628         skb->dev = dev;
1629
1630         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1631
1632         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1633         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1634         ddp->deh_dnet  = usat->sat_addr.s_net;
1635         ddp->deh_snet  = at->src_net;
1636         ddp->deh_dnode = usat->sat_addr.s_node;
1637         ddp->deh_snode = at->src_node;
1638         ddp->deh_dport = usat->sat_port;
1639         ddp->deh_sport = at->src_port;
1640
1641         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1642
1643         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1644         if (err) {
1645                 kfree_skb(skb);
1646                 return -EFAULT;
1647         }
1648
1649         if (sk->sk_no_check == 1)
1650                 ddp->deh_sum = 0;
1651         else
1652                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1653
1654         /*
1655          * Loopback broadcast packets to non gateway targets (ie routes
1656          * to group we are in)
1657          */
1658         if (ddp->deh_dnode == ATADDR_BCAST &&
1659             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1660                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1661
1662                 if (skb2) {
1663                         loopback = 1;
1664                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1665                         if (aarp_send_ddp(dev, skb2,
1666                                           &usat->sat_addr, NULL) == -1)
1667                                 kfree_skb(skb2);
1668                                 /* else queued/sent above in the aarp queue */
1669                 }
1670         }
1671
1672         if (dev->flags & IFF_LOOPBACK || loopback) {
1673                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1674                 /* loop back */
1675                 skb_orphan(skb);
1676                 if (ddp->deh_dnode == ATADDR_BCAST) {
1677                         struct atalk_addr at_lo;
1678
1679                         at_lo.s_node = 0;
1680                         at_lo.s_net  = 0;
1681
1682                         rt = atrtr_find(&at_lo);
1683                         if (!rt) {
1684                                 kfree_skb(skb);
1685                                 return -ENETUNREACH;
1686                         }
1687                         dev = rt->dev;
1688                         skb->dev = dev;
1689                 }
1690                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1691         } else {
1692                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1693                 if (rt->flags & RTF_GATEWAY) {
1694                     gsat.sat_addr = rt->gateway;
1695                     usat = &gsat;
1696                 }
1697
1698                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1699                         kfree_skb(skb);
1700                 /* else queued/sent above in the aarp queue */
1701         }
1702         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1703
1704         return len;
1705 }
1706
1707 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1708                          size_t size, int flags)
1709 {
1710         struct sock *sk = sock->sk;
1711         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1712         struct ddpehdr *ddp;
1713         int copied = 0;
1714         int offset = 0;
1715         int err = 0;
1716         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1717                                                 flags & MSG_DONTWAIT, &err);
1718         if (!skb)
1719                 return err;
1720
1721         /* FIXME: use skb->cb to be able to use shared skbs */
1722         ddp = ddp_hdr(skb);
1723         copied = ntohs(ddp->deh_len_hops) & 1023;
1724
1725         if (sk->sk_type != SOCK_RAW) {
1726                 offset = sizeof(*ddp);
1727                 copied -= offset;
1728         }
1729
1730         if (copied > size) {
1731                 copied = size;
1732                 msg->msg_flags |= MSG_TRUNC;
1733         }
1734         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1735
1736         if (!err) {
1737                 if (sat) {
1738                         sat->sat_family      = AF_APPLETALK;
1739                         sat->sat_port        = ddp->deh_sport;
1740                         sat->sat_addr.s_node = ddp->deh_snode;
1741                         sat->sat_addr.s_net  = ddp->deh_snet;
1742                 }
1743                 msg->msg_namelen = sizeof(*sat);
1744         }
1745
1746         skb_free_datagram(sk, skb);     /* Free the datagram. */
1747         return err ? : copied;
1748 }
1749
1750
1751 /*
1752  * AppleTalk ioctl calls.
1753  */
1754 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1755 {
1756         int rc = -ENOIOCTLCMD;
1757         struct sock *sk = sock->sk;
1758         void __user *argp = (void __user *)arg;
1759
1760         switch (cmd) {
1761                 /* Protocol layer */
1762                 case TIOCOUTQ: {
1763                         long amount = sk->sk_sndbuf -
1764                                       atomic_read(&sk->sk_wmem_alloc);
1765
1766                         if (amount < 0)
1767                                 amount = 0;
1768                         rc = put_user(amount, (int __user *)argp);
1769                         break;
1770                 }
1771                 case TIOCINQ: {
1772                         /*
1773                          * These two are safe on a single CPU system as only
1774                          * user tasks fiddle here
1775                          */
1776                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1777                         long amount = 0;
1778
1779                         if (skb)
1780                                 amount = skb->len - sizeof(struct ddpehdr);
1781                         rc = put_user(amount, (int __user *)argp);
1782                         break;
1783                 }
1784                 case SIOCGSTAMP:
1785                         rc = sock_get_timestamp(sk, argp);
1786                         break;
1787                 case SIOCGSTAMPNS:
1788                         rc = sock_get_timestampns(sk, argp);
1789                         break;
1790                 /* Routing */
1791                 case SIOCADDRT:
1792                 case SIOCDELRT:
1793                         rc = -EPERM;
1794                         if (capable(CAP_NET_ADMIN))
1795                                 rc = atrtr_ioctl(cmd, argp);
1796                         break;
1797                 /* Interface */
1798                 case SIOCGIFADDR:
1799                 case SIOCSIFADDR:
1800                 case SIOCGIFBRDADDR:
1801                 case SIOCATALKDIFADDR:
1802                 case SIOCDIFADDR:
1803                 case SIOCSARP:          /* proxy AARP */
1804                 case SIOCDARP:          /* proxy AARP */
1805                         rtnl_lock();
1806                         rc = atif_ioctl(cmd, argp);
1807                         rtnl_unlock();
1808                         break;
1809         }
1810
1811         return rc;
1812 }
1813
1814
1815 #ifdef CONFIG_COMPAT
1816 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1817 {
1818         /*
1819          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1820          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1821          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1822          * here so there is no generic SIOCPROTOPRIVATE translation in the
1823          * system.
1824          */
1825         return -ENOIOCTLCMD;
1826 }
1827 #endif
1828
1829
1830 static struct net_proto_family atalk_family_ops = {
1831         .family         = PF_APPLETALK,
1832         .create         = atalk_create,
1833         .owner          = THIS_MODULE,
1834 };
1835
1836 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1837         .family         = PF_APPLETALK,
1838         .owner          = THIS_MODULE,
1839         .release        = atalk_release,
1840         .bind           = atalk_bind,
1841         .connect        = atalk_connect,
1842         .socketpair     = sock_no_socketpair,
1843         .accept         = sock_no_accept,
1844         .getname        = atalk_getname,
1845         .poll           = datagram_poll,
1846         .ioctl          = atalk_ioctl,
1847 #ifdef CONFIG_COMPAT
1848         .compat_ioctl   = atalk_compat_ioctl,
1849 #endif
1850         .listen         = sock_no_listen,
1851         .shutdown       = sock_no_shutdown,
1852         .setsockopt     = sock_no_setsockopt,
1853         .getsockopt     = sock_no_getsockopt,
1854         .sendmsg        = atalk_sendmsg,
1855         .recvmsg        = atalk_recvmsg,
1856         .mmap           = sock_no_mmap,
1857         .sendpage       = sock_no_sendpage,
1858 };
1859
1860 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1861
1862 static struct notifier_block ddp_notifier = {
1863         .notifier_call  = ddp_device_event,
1864 };
1865
1866 static struct packet_type ltalk_packet_type = {
1867         .type           = __constant_htons(ETH_P_LOCALTALK),
1868         .func           = ltalk_rcv,
1869 };
1870
1871 static struct packet_type ppptalk_packet_type = {
1872         .type           = __constant_htons(ETH_P_PPPTALK),
1873         .func           = atalk_rcv,
1874 };
1875
1876 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1877
1878 /* Export symbols for use by drivers when AppleTalk is a module */
1879 EXPORT_SYMBOL(aarp_send_ddp);
1880 EXPORT_SYMBOL(atrtr_get_dev);
1881 EXPORT_SYMBOL(atalk_find_dev_addr);
1882
1883 static char atalk_err_snap[] __initdata =
1884         KERN_CRIT "Unable to register DDP with SNAP.\n";
1885
1886 /* Called by proto.c on kernel start up */
1887 static int __init atalk_init(void)
1888 {
1889         int rc = proto_register(&ddp_proto, 0);
1890
1891         if (rc != 0)
1892                 goto out;
1893
1894         (void)sock_register(&atalk_family_ops);
1895         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1896         if (!ddp_dl)
1897                 printk(atalk_err_snap);
1898
1899         dev_add_pack(&ltalk_packet_type);
1900         dev_add_pack(&ppptalk_packet_type);
1901
1902         register_netdevice_notifier(&ddp_notifier);
1903         aarp_proto_init();
1904         atalk_proc_init();
1905         atalk_register_sysctl();
1906 out:
1907         return rc;
1908 }
1909 module_init(atalk_init);
1910
1911 /*
1912  * No explicit module reference count manipulation is needed in the
1913  * protocol. Socket layer sets module reference count for us
1914  * and interfaces reference counting is done
1915  * by the network device layer.
1916  *
1917  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1918  * sockets be closed from user space.
1919  */
1920 static void __exit atalk_exit(void)
1921 {
1922 #ifdef CONFIG_SYSCTL
1923         atalk_unregister_sysctl();
1924 #endif /* CONFIG_SYSCTL */
1925         atalk_proc_exit();
1926         aarp_cleanup_module();  /* General aarp clean-up. */
1927         unregister_netdevice_notifier(&ddp_notifier);
1928         dev_remove_pack(&ltalk_packet_type);
1929         dev_remove_pack(&ppptalk_packet_type);
1930         unregister_snap_client(ddp_dl);
1931         sock_unregister(PF_APPLETALK);
1932         proto_unregister(&ddp_proto);
1933 }
1934 module_exit(atalk_exit);
1935
1936 MODULE_LICENSE("GPL");
1937 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1938 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1939 MODULE_ALIAS_NETPROTO(PF_APPLETALK);