net/appletalk/ddp.c

   1 /*
   2  *      DDP:    An implementation of the AppleTalk DDP protocol for
   3  *              Ethernet 'ELAP'.
   4  *
   5  *              Alan Cox  <alan@lxorguk.ukuu.org.uk>
   6  *
   7  *              With more than a little assistance from
   8  *
   9  *              Wesley Craig <netatalk@umich.edu>
  10  *
  11  *      Fixes:
  12  *              Neil Horman             :       Added missing device ioctls
  13  *              Michael Callahan        :       Made routing work
  14  *              Wesley Craig            :       Fix probing to listen to a
  15  *                                              passed node id.
  16  *              Alan Cox                :       Added send/recvmsg support
  17  *              Alan Cox                :       Moved at. to protinfo in
  18  *                                              socket.
  19  *              Alan Cox                :       Added firewall hooks.
  20  *              Alan Cox                :       Supports new ARPHRD_LOOPBACK
  21  *              Christer Weinigel       :       Routing and /proc fixes.
  22  *              Bradford Johnson        :       LocalTalk.
  23  *              Tom Dyas                :       Module support.
  24  *              Alan Cox                :       Hooks for PPP (based on the
  25  *                                              LocalTalk hook).
  26  *              Alan Cox                :       Posix bits
  27  *              Alan Cox/Mike Freeman   :       Possible fix to NBP problems
  28  *              Bradford Johnson        :       IP-over-DDP (experimental)
  29  *              Jay Schulist            :       Moved IP-over-DDP to its own
  30  *                                              driver file. (ipddp.c & ipddp.h)
  31  *              Jay Schulist            :       Made work as module with
  32  *                                              AppleTalk drivers, cleaned it.
  33  *              Rob Newberry            :       Added proxy AARP and AARP
  34  *                                              procfs, moved probing to AARP
  35  *                                              module.
  36  *              Adrian Sun/
  37  *              Michael Zuelsdorff      :       fix for net.0 packets. don't
  38  *                                              allow illegal ether/tokentalk
  39  *                                              port assignment. we lose a
  40  *                                              valid localtalk port as a
  41  *                                              result.
  42  *              Arnaldo C. de Melo      :       Cleanup, in preparation for
  43  *                                              shared skb support 8)
  44  *              Arnaldo C. de Melo      :       Move proc stuff to atalk_proc.c,
  45  *                                              use seq_file
  46  *
  47  *              This program is free software; you can redistribute it and/or
  48  *              modify it under the terms of the GNU General Public License
  49  *              as published by the Free Software Foundation; either version
  50  *              2 of the License, or (at your option) any later version.
  51  *
  52  */
  53
  54 #include <linux/capability.h>
  55 #include <linux/module.h>
  56 #include <linux/if_arp.h>
  57 #include <linux/smp_lock.h>
  58 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
  59 #include <linux/compat.h>
  60 #include <linux/slab.h>
  61 #include <net/datalink.h>
  62 #include <net/psnap.h>
  63 #include <net/sock.h>
  64 #include <net/tcp_states.h>
  65 #include <net/route.h>
  66 #include <linux/atalk.h>
  67 #include "../core/kmap_skb.h"
  68
  69 struct datalink_proto *ddp_dl, *aarp_dl;
  70 static const struct proto_ops atalk_dgram_ops;
  71
  72 /**************************************************************************\
  73 *                                                                          *
  74 * Handlers for the socket list.                                            *
  75 *                                                                          *
  76 \**************************************************************************/
  77
  78 HLIST_HEAD(atalk_sockets);
  79 DEFINE_RWLOCK(atalk_sockets_lock);
  80
  81 static inline void __atalk_insert_socket(struct sock *sk)
  82 {
  83         sk_add_node(sk, &atalk_sockets);
  84 }
  85
  86 static inline void atalk_remove_socket(struct sock *sk)
  87 {
  88         write_lock_bh(&atalk_sockets_lock);
  89         sk_del_node_init(sk);
  90         write_unlock_bh(&atalk_sockets_lock);
  91 }
  92
  93 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  94                                         struct atalk_iface *atif)
  95 {
  96         struct sock *s;
  97         struct hlist_node *node;
  98
  99         read_lock_bh(&atalk_sockets_lock);
 100         sk_for_each(s, node, &atalk_sockets) {
 101                 struct atalk_sock *at = at_sk(s);
 102
 103                 if (to->sat_port != at->src_port)
 104                         continue;
 105
 106                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 107                     to->sat_addr.s_node == ATADDR_BCAST)
 108                         goto found;
 109
 110                 if (to->sat_addr.s_net == at->src_net &&
 111                     (to->sat_addr.s_node == at->src_node ||
 112                      to->sat_addr.s_node == ATADDR_BCAST ||
 113                      to->sat_addr.s_node == ATADDR_ANYNODE))
 114                         goto found;
 115
 116                 /* XXXX.0 -- we got a request for this router. make sure
 117                  * that the node is appropriately set. */
 118                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 119                     to->sat_addr.s_net != ATADDR_ANYNET &&
 120                     atif->address.s_node == at->src_node) {
 121                         to->sat_addr.s_node = atif->address.s_node;
 122                         goto found;
 123                 }
 124         }
 125         s = NULL;
 126 found:
 127         read_unlock_bh(&atalk_sockets_lock);
 128         return s;
 129 }
 130
 131 /**
 132  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 133  * @sk - socket to insert in the list if it is not there already
 134  * @sat - address to search for
 135  *
 136  * Try to find a socket matching ADDR in the socket list, if found then return
 137  * it. If not, insert SK into the socket list.
 138  *
 139  * This entire operation must execute atomically.
 140  */
 141 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 142                                                 struct sockaddr_at *sat)
 143 {
 144         struct sock *s;
 145         struct hlist_node *node;
 146         struct atalk_sock *at;
 147
 148         write_lock_bh(&atalk_sockets_lock);
 149         sk_for_each(s, node, &atalk_sockets) {
 150                 at = at_sk(s);
 151
 152                 if (at->src_net == sat->sat_addr.s_net &&
 153                     at->src_node == sat->sat_addr.s_node &&
 154                     at->src_port == sat->sat_port)
 155                         goto found;
 156         }
 157         s = NULL;
 158         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 159 found:
 160         write_unlock_bh(&atalk_sockets_lock);
 161         return s;
 162 }
 163
 164 static void atalk_destroy_timer(unsigned long data)
 165 {
 166         struct sock *sk = (struct sock *)data;
 167
 168         if (sk_has_allocations(sk)) {
 169                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 170                 add_timer(&sk->sk_timer);
 171         } else
 172                 sock_put(sk);
 173 }
 174
 175 static inline void atalk_destroy_socket(struct sock *sk)
 176 {
 177         atalk_remove_socket(sk);
 178         skb_queue_purge(&sk->sk_receive_queue);
 179
 180         if (sk_has_allocations(sk)) {
 181                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
 182                                 (unsigned long)sk);
 183                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 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         struct net_device *dev = ptr;
 651
 652         if (!net_eq(dev_net(dev), &init_net))
 653                 return NOTIFY_DONE;
 654
 655         if (event == NETDEV_DOWN)
 656                 /* Discard any use of this */
 657                 atalk_dev_down(dev);
 658
 659         return NOTIFY_DONE;
 660 }
 661
 662 /* ioctl calls. Shouldn't even need touching */
 663 /* Device configuration ioctl calls */
 664 static int atif_ioctl(int cmd, void __user *arg)
 665 {
 666         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 667         struct ifreq atreq;
 668         struct atalk_netrange *nr;
 669         struct sockaddr_at *sa;
 670         struct net_device *dev;
 671         struct atalk_iface *atif;
 672         int ct;
 673         int limit;
 674         struct rtentry rtdef;
 675         int add_route;
 676
 677         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 678                 return -EFAULT;
 679
 680         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
 681         if (!dev)
 682                 return -ENODEV;
 683
 684         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 685         atif = atalk_find_dev(dev);
 686
 687         switch (cmd) {
 688                 case SIOCSIFADDR:
 689                         if (!capable(CAP_NET_ADMIN))
 690                                 return -EPERM;
 691                         if (sa->sat_family != AF_APPLETALK)
 692                                 return -EINVAL;
 693                         if (dev->type != ARPHRD_ETHER &&
 694                             dev->type != ARPHRD_LOOPBACK &&
 695                             dev->type != ARPHRD_LOCALTLK &&
 696                             dev->type != ARPHRD_PPP)
 697                                 return -EPROTONOSUPPORT;
 698
 699                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 700                         add_route = 1;
 701
 702                         /*
 703                          * if this is a point-to-point iface, and we already
 704                          * have an iface for this AppleTalk address, then we
 705                          * should not add a route
 706                          */
 707                         if ((dev->flags & IFF_POINTOPOINT) &&
 708                             atalk_find_interface(sa->sat_addr.s_net,
 709                                                  sa->sat_addr.s_node)) {
 710                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 711                                                   "interface added with "
 712                                                   "existing address\n");
 713                                 add_route = 0;
 714                         }
 715
 716                         /*
 717                          * Phase 1 is fine on LocalTalk but we don't do
 718                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 719                          */
 720                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 721                                 return -EPROTONOSUPPORT;
 722                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 723                             sa->sat_addr.s_node == 254)
 724                                 return -EINVAL;
 725                         if (atif) {
 726                                 /* Already setting address */
 727                                 if (atif->status & ATIF_PROBE)
 728                                         return -EBUSY;
 729
 730                                 atif->address.s_net  = sa->sat_addr.s_net;
 731                                 atif->address.s_node = sa->sat_addr.s_node;
 732                                 atrtr_device_down(dev); /* Flush old routes */
 733                         } else {
 734                                 atif = atif_add_device(dev, &sa->sat_addr);
 735                                 if (!atif)
 736                                         return -ENOMEM;
 737                         }
 738                         atif->nets = *nr;
 739
 740                         /*
 741                          * Check if the chosen address is used. If so we
 742                          * error and atalkd will try another.
 743                          */
 744
 745                         if (!(dev->flags & IFF_LOOPBACK) &&
 746                             !(dev->flags & IFF_POINTOPOINT) &&
 747                             atif_probe_device(atif) < 0) {
 748                                 atif_drop_device(dev);
 749                                 return -EADDRINUSE;
 750                         }
 751
 752                         /* Hey it worked - add the direct routes */
 753                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 754                         sa->sat_family = AF_APPLETALK;
 755                         sa->sat_addr.s_net  = atif->address.s_net;
 756                         sa->sat_addr.s_node = atif->address.s_node;
 757                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 758                         rtdef.rt_flags = RTF_UP;
 759                         sa->sat_family = AF_APPLETALK;
 760                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 761                         if (dev->flags & IFF_LOOPBACK ||
 762                             dev->flags & IFF_POINTOPOINT)
 763                                 rtdef.rt_flags |= RTF_HOST;
 764
 765                         /* Routerless initial state */
 766                         if (nr->nr_firstnet == htons(0) &&
 767                             nr->nr_lastnet == htons(0xFFFE)) {
 768                                 sa->sat_addr.s_net = atif->address.s_net;
 769                                 atrtr_create(&rtdef, dev);
 770                                 atrtr_set_default(dev);
 771                         } else {
 772                                 limit = ntohs(nr->nr_lastnet);
 773                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 774                                         printk(KERN_WARNING "Too many routes/"
 775                                                             "iface.\n");
 776                                         return -EINVAL;
 777                                 }
 778                                 if (add_route)
 779                                         for (ct = ntohs(nr->nr_firstnet);
 780                                              ct <= limit; ct++) {
 781                                                 sa->sat_addr.s_net = htons(ct);
 782                                                 atrtr_create(&rtdef, dev);
 783                                         }
 784                         }
 785                         dev_mc_add_global(dev, aarp_mcast);
 786                         return 0;
 787
 788                 case SIOCGIFADDR:
 789                         if (!atif)
 790                                 return -EADDRNOTAVAIL;
 791
 792                         sa->sat_family = AF_APPLETALK;
 793                         sa->sat_addr = atif->address;
 794                         break;
 795
 796                 case SIOCGIFBRDADDR:
 797                         if (!atif)
 798                                 return -EADDRNOTAVAIL;
 799
 800                         sa->sat_family = AF_APPLETALK;
 801                         sa->sat_addr.s_net = atif->address.s_net;
 802                         sa->sat_addr.s_node = ATADDR_BCAST;
 803                         break;
 804
 805                 case SIOCATALKDIFADDR:
 806                 case SIOCDIFADDR:
 807                         if (!capable(CAP_NET_ADMIN))
 808                                 return -EPERM;
 809                         if (sa->sat_family != AF_APPLETALK)
 810                                 return -EINVAL;
 811                         atalk_dev_down(dev);
 812                         break;
 813
 814                 case SIOCSARP:
 815                         if (!capable(CAP_NET_ADMIN))
 816                                 return -EPERM;
 817                         if (sa->sat_family != AF_APPLETALK)
 818                                 return -EINVAL;
 819                         /*
 820                          * for now, we only support proxy AARP on ELAP;
 821                          * we should be able to do it for LocalTalk, too.
 822                          */
 823                         if (dev->type != ARPHRD_ETHER)
 824                                 return -EPROTONOSUPPORT;
 825
 826                         /*
 827                          * atif points to the current interface on this network;
 828                          * we aren't concerned about its current status (at
 829                          * least for now), but it has all the settings about
 830                          * the network we're going to probe. Consequently, it
 831                          * must exist.
 832                          */
 833                         if (!atif)
 834                                 return -EADDRNOTAVAIL;
 835
 836                         nr = (struct atalk_netrange *)&(atif->nets);
 837                         /*
 838                          * Phase 1 is fine on Localtalk but we don't do
 839                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 840                          */
 841                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 842                                 return -EPROTONOSUPPORT;
 843
 844                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 845                             sa->sat_addr.s_node == 254)
 846                                 return -EINVAL;
 847
 848                         /*
 849                          * Check if the chosen address is used. If so we
 850                          * error and ATCP will try another.
 851                          */
 852                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 853                                 return -EADDRINUSE;
 854
 855                         /*
 856                          * We now have an address on the local network, and
 857                          * the AARP code will defend it for us until we take it
 858                          * down. We don't set up any routes right now, because
 859                          * ATCP will install them manually via SIOCADDRT.
 860                          */
 861                         break;
 862
 863                 case SIOCDARP:
 864                         if (!capable(CAP_NET_ADMIN))
 865                                 return -EPERM;
 866                         if (sa->sat_family != AF_APPLETALK)
 867                                 return -EINVAL;
 868                         if (!atif)
 869                                 return -EADDRNOTAVAIL;
 870
 871                         /* give to aarp module to remove proxy entry */
 872                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 873                         return 0;
 874         }
 875
 876         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 877 }
 878
 879 /* Routing ioctl() calls */
 880 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 881 {
 882         struct rtentry rt;
 883
 884         if (copy_from_user(&rt, arg, sizeof(rt)))
 885                 return -EFAULT;
 886
 887         switch (cmd) {
 888                 case SIOCDELRT:
 889                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 890                                 return -EINVAL;
 891                         return atrtr_delete(&((struct sockaddr_at *)
 892                                                 &rt.rt_dst)->sat_addr);
 893
 894                 case SIOCADDRT: {
 895                         struct net_device *dev = NULL;
 896                         if (rt.rt_dev) {
 897                                 char name[IFNAMSIZ];
 898                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 899                                         return -EFAULT;
 900                                 name[IFNAMSIZ-1] = '\0';
 901                                 dev = __dev_get_by_name(&init_net, name);
 902                                 if (!dev)
 903                                         return -ENODEV;
 904                         }
 905                         return atrtr_create(&rt, dev);
 906                 }
 907         }
 908         return -EINVAL;
 909 }
 910
 911 /**************************************************************************\
 912 *                                                                          *
 913 * Handling for system calls applied via the various interfaces to an       *
 914 * AppleTalk socket object.                                                 *
 915 *                                                                          *
 916 \**************************************************************************/
 917
 918 /*
 919  * Checksum: This is 'optional'. It's quite likely also a good
 920  * candidate for assembler hackery 8)
 921  */
 922 static unsigned long atalk_sum_partial(const unsigned char *data,
 923                                        int len, unsigned long sum)
 924 {
 925         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 926         while (len--) {
 927                 sum += *data++;
 928                 sum = rol16(sum, 1);
 929         }
 930         return sum;
 931 }
 932
 933 /*  Checksum skb data --  similar to skb_checksum  */
 934 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 935                                    int len, unsigned long sum)
 936 {
 937         int start = skb_headlen(skb);
 938         struct sk_buff *frag_iter;
 939         int i, copy;
 940
 941         /* checksum stuff in header space */
 942         if ( (copy = start - offset) > 0) {
 943                 if (copy > len)
 944                         copy = len;
 945                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 946                 if ( (len -= copy) == 0)
 947                         return sum;
 948
 949                 offset += copy;
 950         }
 951
 952         /* checksum stuff in frags */
 953         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 954                 int end;
 955
 956                 WARN_ON(start > offset + len);
 957
 958                 end = start + 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                                                   offset - start, copy, sum);
 968                         kunmap_skb_frag(vaddr);
 969
 970                         if (!(len -= copy))
 971                                 return sum;
 972                         offset += copy;
 973                 }
 974                 start = end;
 975         }
 976
 977         skb_walk_frags(skb, frag_iter) {
 978                 int end;
 979
 980                 WARN_ON(start > offset + len);
 981
 982                 end = start + frag_iter->len;
 983                 if ((copy = end - offset) > 0) {
 984                         if (copy > len)
 985                                 copy = len;
 986                         sum = atalk_sum_skb(frag_iter, offset - start,
 987                                             copy, sum);
 988                         if ((len -= copy) == 0)
 989                                 return sum;
 990                         offset += copy;
 991                 }
 992                 start = end;
 993         }
 994
 995         BUG_ON(len > 0);
 996
 997         return sum;
 998 }
 999
1000 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1001 {
1002         unsigned long sum;
1003
1004         /* skip header 4 bytes */
1005         sum = atalk_sum_skb(skb, 4, len-4, 0);
1006
1007         /* Use 0xFFFF for 0. 0 itself means none */
1008         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1009 }
1010
1011 static struct proto ddp_proto = {
1012         .name     = "DDP",
1013         .owner    = THIS_MODULE,
1014         .obj_size = sizeof(struct atalk_sock),
1015 };
1016
1017 /*
1018  * Create a socket. Initialise the socket, blank the addresses
1019  * set the state.
1020  */
1021 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1022                         int kern)
1023 {
1024         struct sock *sk;
1025         int rc = -ESOCKTNOSUPPORT;
1026
1027         if (!net_eq(net, &init_net))
1028                 return -EAFNOSUPPORT;
1029
1030         /*
1031          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1032          * and gives you the full ELAP frame. Should be handy for CAP 8)
1033          */
1034         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1035                 goto out;
1036         rc = -ENOMEM;
1037         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1038         if (!sk)
1039                 goto out;
1040         rc = 0;
1041         sock->ops = &atalk_dgram_ops;
1042         sock_init_data(sock, sk);
1043
1044         /* Checksums on by default */
1045         sock_set_flag(sk, SOCK_ZAPPED);
1046 out:
1047         return rc;
1048 }
1049
1050 /* Free a socket. No work needed */
1051 static int atalk_release(struct socket *sock)
1052 {
1053         struct sock *sk = sock->sk;
1054
1055         lock_kernel();
1056         if (sk) {
1057                 sock_orphan(sk);
1058                 sock->sk = NULL;
1059                 atalk_destroy_socket(sk);
1060         }
1061         unlock_kernel();
1062         return 0;
1063 }
1064
1065 /**
1066  * atalk_pick_and_bind_port - Pick a source port when one is not given
1067  * @sk - socket to insert into the tables
1068  * @sat - address to search for
1069  *
1070  * Pick a source port when one is not given. If we can find a suitable free
1071  * one, we insert the socket into the tables using it.
1072  *
1073  * This whole operation must be atomic.
1074  */
1075 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1076 {
1077         int retval;
1078
1079         write_lock_bh(&atalk_sockets_lock);
1080
1081         for (sat->sat_port = ATPORT_RESERVED;
1082              sat->sat_port < ATPORT_LAST;
1083              sat->sat_port++) {
1084                 struct sock *s;
1085                 struct hlist_node *node;
1086
1087                 sk_for_each(s, node, &atalk_sockets) {
1088                         struct atalk_sock *at = at_sk(s);
1089
1090                         if (at->src_net == sat->sat_addr.s_net &&
1091                             at->src_node == sat->sat_addr.s_node &&
1092                             at->src_port == sat->sat_port)
1093                                 goto try_next_port;
1094                 }
1095
1096                 /* Wheee, it's free, assign and insert. */
1097                 __atalk_insert_socket(sk);
1098                 at_sk(sk)->src_port = sat->sat_port;
1099                 retval = 0;
1100                 goto out;
1101
1102 try_next_port:;
1103         }
1104
1105         retval = -EBUSY;
1106 out:
1107         write_unlock_bh(&atalk_sockets_lock);
1108         return retval;
1109 }
1110
1111 static int atalk_autobind(struct sock *sk)
1112 {
1113         struct atalk_sock *at = at_sk(sk);
1114         struct sockaddr_at sat;
1115         struct atalk_addr *ap = atalk_find_primary();
1116         int n = -EADDRNOTAVAIL;
1117
1118         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1119                 goto out;
1120
1121         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1122         at->src_node = sat.sat_addr.s_node = ap->s_node;
1123
1124         n = atalk_pick_and_bind_port(sk, &sat);
1125         if (!n)
1126                 sock_reset_flag(sk, SOCK_ZAPPED);
1127 out:
1128         return n;
1129 }
1130
1131 /* Set the address 'our end' of the connection */
1132 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1133 {
1134         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1135         struct sock *sk = sock->sk;
1136         struct atalk_sock *at = at_sk(sk);
1137         int err;
1138
1139         if (!sock_flag(sk, SOCK_ZAPPED) ||
1140             addr_len != sizeof(struct sockaddr_at))
1141                 return -EINVAL;
1142
1143         if (addr->sat_family != AF_APPLETALK)
1144                 return -EAFNOSUPPORT;
1145
1146         lock_kernel();
1147         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1148                 struct atalk_addr *ap = atalk_find_primary();
1149
1150                 err = -EADDRNOTAVAIL;
1151                 if (!ap)
1152                         goto out;
1153
1154                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1155                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1156         } else {
1157                 err = -EADDRNOTAVAIL;
1158                 if (!atalk_find_interface(addr->sat_addr.s_net,
1159                                           addr->sat_addr.s_node))
1160                         goto out;
1161
1162                 at->src_net  = addr->sat_addr.s_net;
1163                 at->src_node = addr->sat_addr.s_node;
1164         }
1165
1166         if (addr->sat_port == ATADDR_ANYPORT) {
1167                 err = atalk_pick_and_bind_port(sk, addr);
1168
1169                 if (err < 0)
1170                         goto out;
1171         } else {
1172                 at->src_port = addr->sat_port;
1173
1174                 err = -EADDRINUSE;
1175                 if (atalk_find_or_insert_socket(sk, addr))
1176                         goto out;
1177         }
1178
1179         sock_reset_flag(sk, SOCK_ZAPPED);
1180         err = 0;
1181 out:
1182         unlock_kernel();
1183         return err;
1184 }
1185
1186 /* Set the address we talk to */
1187 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1188                          int addr_len, int flags)
1189 {
1190         struct sock *sk = sock->sk;
1191         struct atalk_sock *at = at_sk(sk);
1192         struct sockaddr_at *addr;
1193         int err;
1194
1195         sk->sk_state   = TCP_CLOSE;
1196         sock->state = SS_UNCONNECTED;
1197
1198         if (addr_len != sizeof(*addr))
1199                 return -EINVAL;
1200
1201         addr = (struct sockaddr_at *)uaddr;
1202
1203         if (addr->sat_family != AF_APPLETALK)
1204                 return -EAFNOSUPPORT;
1205
1206         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1207             !sock_flag(sk, SOCK_BROADCAST)) {
1208 #if 1
1209                 printk(KERN_WARNING "%s is broken and did not set "
1210                                     "SO_BROADCAST. It will break when 2.2 is "
1211                                     "released.\n",
1212                         current->comm);
1213 #else
1214                 return -EACCES;
1215 #endif
1216         }
1217
1218         lock_kernel();
1219         err = -EBUSY;
1220         if (sock_flag(sk, SOCK_ZAPPED))
1221                 if (atalk_autobind(sk) < 0)
1222                         goto out;
1223
1224         err = -ENETUNREACH;
1225         if (!atrtr_get_dev(&addr->sat_addr))
1226                 goto out;
1227
1228         at->dest_port = addr->sat_port;
1229         at->dest_net  = addr->sat_addr.s_net;
1230         at->dest_node = addr->sat_addr.s_node;
1231
1232         sock->state  = SS_CONNECTED;
1233         sk->sk_state = TCP_ESTABLISHED;
1234         err = 0;
1235 out:
1236         unlock_kernel();
1237         return err;
1238 }
1239
1240 /*
1241  * Find the name of an AppleTalk socket. Just copy the right
1242  * fields into the sockaddr.
1243  */
1244 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1245                          int *uaddr_len, int peer)
1246 {
1247         struct sockaddr_at sat;
1248         struct sock *sk = sock->sk;
1249         struct atalk_sock *at = at_sk(sk);
1250         int err;
1251
1252         lock_kernel();
1253         err = -ENOBUFS;
1254         if (sock_flag(sk, SOCK_ZAPPED))
1255                 if (atalk_autobind(sk) < 0)
1256                         goto out;
1257
1258         *uaddr_len = sizeof(struct sockaddr_at);
1259         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
1260
1261         if (peer) {
1262                 err = -ENOTCONN;
1263                 if (sk->sk_state != TCP_ESTABLISHED)
1264                         goto out;
1265
1266                 sat.sat_addr.s_net  = at->dest_net;
1267                 sat.sat_addr.s_node = at->dest_node;
1268                 sat.sat_port        = at->dest_port;
1269         } else {
1270                 sat.sat_addr.s_net  = at->src_net;
1271                 sat.sat_addr.s_node = at->src_node;
1272                 sat.sat_port        = at->src_port;
1273         }
1274
1275         err = 0;
1276         sat.sat_family = AF_APPLETALK;
1277         memcpy(uaddr, &sat, sizeof(sat));
1278
1279 out:
1280         unlock_kernel();
1281         return err;
1282 }
1283
1284 static unsigned int atalk_poll(struct file *file, struct socket *sock,
1285                            poll_table *wait)
1286 {
1287         int err;
1288         lock_kernel();
1289         err = datagram_poll(file, sock, wait);
1290         unlock_kernel();
1291         return err;
1292 }
1293
1294 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1295 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1296 {
1297         return skb->data[12] == 22;
1298 }
1299
1300 static int handle_ip_over_ddp(struct sk_buff *skb)
1301 {
1302         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1303         struct net_device_stats *stats;
1304
1305         /* This needs to be able to handle ipddp"N" devices */
1306         if (!dev) {
1307                 kfree_skb(skb);
1308                 return NET_RX_DROP;
1309         }
1310
1311         skb->protocol = htons(ETH_P_IP);
1312         skb_pull(skb, 13);
1313         skb->dev   = dev;
1314         skb_reset_transport_header(skb);
1315
1316         stats = netdev_priv(dev);
1317         stats->rx_packets++;
1318         stats->rx_bytes += skb->len + 13;
1319         return netif_rx(skb);  /* Send the SKB up to a higher place. */
1320 }
1321 #else
1322 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1323 #define is_ip_over_ddp(skb) 0
1324 #define handle_ip_over_ddp(skb) 0
1325 #endif
1326
1327 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1328                               struct ddpehdr *ddp, __u16 len_hops, int origlen)
1329 {
1330         struct atalk_route *rt;
1331         struct atalk_addr ta;
1332
1333         /*
1334          * Don't route multicast, etc., packets, or packets sent to "this
1335          * network"
1336          */
1337         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1338                 /*
1339                  * FIXME:
1340                  *
1341                  * Can it ever happen that a packet is from a PPP iface and
1342                  * needs to be broadcast onto the default network?
1343                  */
1344                 if (dev->type == ARPHRD_PPP)
1345                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1346                                           "packet received from PPP iface\n");
1347                 goto free_it;
1348         }
1349
1350         ta.s_net  = ddp->deh_dnet;
1351         ta.s_node = ddp->deh_dnode;
1352
1353         /* Route the packet */
1354         rt = atrtr_find(&ta);
1355         /* increment hops count */
1356         len_hops += 1 << 10;
1357         if (!rt || !(len_hops & (15 << 10)))
1358                 goto free_it;
1359
1360         /* FIXME: use skb->cb to be able to use shared skbs */
1361
1362         /*
1363          * Route goes through another gateway, so set the target to the
1364          * gateway instead.
1365          */
1366
1367         if (rt->flags & RTF_GATEWAY) {
1368                 ta.s_net  = rt->gateway.s_net;
1369                 ta.s_node = rt->gateway.s_node;
1370         }
1371
1372         /* Fix up skb->len field */
1373         skb_trim(skb, min_t(unsigned int, origlen,
1374                             (rt->dev->hard_header_len +
1375                              ddp_dl->header_length + (len_hops & 1023))));
1376
1377         /* FIXME: use skb->cb to be able to use shared skbs */
1378         ddp->deh_len_hops = htons(len_hops);
1379
1380         /*
1381          * Send the buffer onwards
1382          *
1383          * Now we must always be careful. If it's come from LocalTalk to
1384          * EtherTalk it might not fit
1385          *
1386          * Order matters here: If a packet has to be copied to make a new
1387          * headroom (rare hopefully) then it won't need unsharing.
1388          *
1389          * Note. ddp-> becomes invalid at the realloc.
1390          */
1391         if (skb_headroom(skb) < 22) {
1392                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1393                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1394                 kfree_skb(skb);
1395                 skb = nskb;
1396         } else
1397                 skb = skb_unshare(skb, GFP_ATOMIC);
1398
1399         /*
1400          * If the buffer didn't vanish into the lack of space bitbucket we can
1401          * send it.
1402          */
1403         if (skb == NULL)
1404                 goto drop;
1405
1406         if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1407                 return NET_RX_DROP;
1408         return NET_RX_SUCCESS;
1409 free_it:
1410         kfree_skb(skb);
1411 drop:
1412         return NET_RX_DROP;
1413 }
1414
1415 /**
1416  *      atalk_rcv - Receive a packet (in skb) from device dev
1417  *      @skb - packet received
1418  *      @dev - network device where the packet comes from
1419  *      @pt - packet type
1420  *
1421  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1422  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1423  *      is the DDP header, skb->len is the DDP length. The physical headers
1424  *      have been extracted. PPP should probably pass frames marked as for this
1425  *      layer.  [ie ARPHRD_ETHERTALK]
1426  */
1427 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1428                      struct packet_type *pt, struct net_device *orig_dev)
1429 {
1430         struct ddpehdr *ddp;
1431         struct sock *sock;
1432         struct atalk_iface *atif;
1433         struct sockaddr_at tosat;
1434         int origlen;
1435         __u16 len_hops;
1436
1437         if (!net_eq(dev_net(dev), &init_net))
1438                 goto drop;
1439
1440         /* Don't mangle buffer if shared */
1441         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1442                 goto out;
1443
1444         /* Size check and make sure header is contiguous */
1445         if (!pskb_may_pull(skb, sizeof(*ddp)))
1446                 goto drop;
1447
1448         ddp = ddp_hdr(skb);
1449
1450         len_hops = ntohs(ddp->deh_len_hops);
1451
1452         /* Trim buffer in case of stray trailing data */
1453         origlen = skb->len;
1454         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1455
1456         /*
1457          * Size check to see if ddp->deh_len was crap
1458          * (Otherwise we'll detonate most spectacularly
1459          * in the middle of atalk_checksum() or recvmsg()).
1460          */
1461         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1462                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1463                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1464                 goto drop;
1465         }
1466
1467         /*
1468          * Any checksums. Note we don't do htons() on this == is assumed to be
1469          * valid for net byte orders all over the networking code...
1470          */
1471         if (ddp->deh_sum &&
1472             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1473                 /* Not a valid AppleTalk frame - dustbin time */
1474                 goto drop;
1475
1476         /* Check the packet is aimed at us */
1477         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1478                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1479         else
1480                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1481
1482         if (!atif) {
1483                 /* Not ours, so we route the packet via the correct
1484                  * AppleTalk iface
1485                  */
1486                 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1487         }
1488
1489         /* if IP over DDP is not selected this code will be optimized out */
1490         if (is_ip_over_ddp(skb))
1491                 return handle_ip_over_ddp(skb);
1492         /*
1493          * Which socket - atalk_search_socket() looks for a *full match*
1494          * of the <net, node, port> tuple.
1495          */
1496         tosat.sat_addr.s_net  = ddp->deh_dnet;
1497         tosat.sat_addr.s_node = ddp->deh_dnode;
1498         tosat.sat_port        = ddp->deh_dport;
1499
1500         sock = atalk_search_socket(&tosat, atif);
1501         if (!sock) /* But not one of our sockets */
1502                 goto drop;
1503
1504         /* Queue packet (standard) */
1505         skb->sk = sock;
1506
1507         if (sock_queue_rcv_skb(sock, skb) < 0)
1508                 goto drop;
1509
1510         return NET_RX_SUCCESS;
1511
1512 drop:
1513         kfree_skb(skb);
1514 out:
1515         return NET_RX_DROP;
1516
1517 }
1518
1519 /*
1520  * Receive a LocalTalk frame. We make some demands on the caller here.
1521  * Caller must provide enough headroom on the packet to pull the short
1522  * header and append a long one.
1523  */
1524 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1525                      struct packet_type *pt, struct net_device *orig_dev)
1526 {
1527         if (!net_eq(dev_net(dev), &init_net))
1528                 goto freeit;
1529
1530         /* Expand any short form frames */
1531         if (skb_mac_header(skb)[2] == 1) {
1532                 struct ddpehdr *ddp;
1533                 /* Find our address */
1534                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1535
1536                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1537                         goto freeit;
1538
1539                 /* Don't mangle buffer if shared */
1540                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1541                         return 0;
1542
1543                 /*
1544                  * The push leaves us with a ddephdr not an shdr, and
1545                  * handily the port bytes in the right place preset.
1546                  */
1547                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1548
1549                 /* Now fill in the long header */
1550
1551                 /*
1552                  * These two first. The mac overlays the new source/dest
1553                  * network information so we MUST copy these before
1554                  * we write the network numbers !
1555                  */
1556
1557                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1558                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1559
1560                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1561                 ddp->deh_snet  = ap->s_net;
1562                 ddp->deh_sum   = 0;             /* No checksum */
1563                 /*
1564                  * Not sure about this bit...
1565                  */
1566                 /* Non routable, so force a drop if we slip up later */
1567                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1568         }
1569         skb_reset_transport_header(skb);
1570
1571         return atalk_rcv(skb, dev, pt, orig_dev);
1572 freeit:
1573         kfree_skb(skb);
1574         return 0;
1575 }
1576
1577 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1578                          size_t len)
1579 {
1580         struct sock *sk = sock->sk;
1581         struct atalk_sock *at = at_sk(sk);
1582         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1583         int flags = msg->msg_flags;
1584         int loopback = 0;
1585         struct sockaddr_at local_satalk, gsat;
1586         struct sk_buff *skb;
1587         struct net_device *dev;
1588         struct ddpehdr *ddp;
1589         int size;
1590         struct atalk_route *rt;
1591         int err;
1592
1593         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1594                 return -EINVAL;
1595
1596         if (len > DDP_MAXSZ)
1597                 return -EMSGSIZE;
1598
1599         lock_kernel();
1600         if (usat) {
1601                 err = -EBUSY;
1602                 if (sock_flag(sk, SOCK_ZAPPED))
1603                         if (atalk_autobind(sk) < 0)
1604                                 goto out;
1605
1606                 err = -EINVAL;
1607                 if (msg->msg_namelen < sizeof(*usat) ||
1608                     usat->sat_family != AF_APPLETALK)
1609                         goto out;
1610
1611                 err = -EPERM;
1612                 /* netatalk didn't implement this check */
1613                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1614                     !sock_flag(sk, SOCK_BROADCAST)) {
1615                         goto out;
1616                 }
1617         } else {
1618                 err = -ENOTCONN;
1619                 if (sk->sk_state != TCP_ESTABLISHED)
1620                         goto out;
1621                 usat = &local_satalk;
1622                 usat->sat_family      = AF_APPLETALK;
1623                 usat->sat_port        = at->dest_port;
1624                 usat->sat_addr.s_node = at->dest_node;
1625                 usat->sat_addr.s_net  = at->dest_net;
1626         }
1627
1628         /* Build a packet */
1629         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1630
1631         /* For headers */
1632         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1633
1634         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1635                 rt = atrtr_find(&usat->sat_addr);
1636         } else {
1637                 struct atalk_addr at_hint;
1638
1639                 at_hint.s_node = 0;
1640                 at_hint.s_net  = at->src_net;
1641
1642                 rt = atrtr_find(&at_hint);
1643         }
1644         err = ENETUNREACH;
1645         if (!rt)
1646                 goto out;
1647
1648         dev = rt->dev;
1649
1650         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1651                         sk, size, dev->name);
1652
1653         size += dev->hard_header_len;
1654         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1655         if (!skb)
1656                 goto out;
1657
1658         skb->sk = sk;
1659         skb_reserve(skb, ddp_dl->header_length);
1660         skb_reserve(skb, dev->hard_header_len);
1661         skb->dev = dev;
1662
1663         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1664
1665         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1666         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1667         ddp->deh_dnet  = usat->sat_addr.s_net;
1668         ddp->deh_snet  = at->src_net;
1669         ddp->deh_dnode = usat->sat_addr.s_node;
1670         ddp->deh_snode = at->src_node;
1671         ddp->deh_dport = usat->sat_port;
1672         ddp->deh_sport = at->src_port;
1673
1674         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1675
1676         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1677         if (err) {
1678                 kfree_skb(skb);
1679                 err = -EFAULT;
1680                 goto out;
1681         }
1682
1683         if (sk->sk_no_check == 1)
1684                 ddp->deh_sum = 0;
1685         else
1686                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1687
1688         /*
1689          * Loopback broadcast packets to non gateway targets (ie routes
1690          * to group we are in)
1691          */
1692         if (ddp->deh_dnode == ATADDR_BCAST &&
1693             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1694                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1695
1696                 if (skb2) {
1697                         loopback = 1;
1698                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1699                         /*
1700                          * If it fails it is queued/sent above in the aarp queue
1701                          */
1702                         aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1703                 }
1704         }
1705
1706         if (dev->flags & IFF_LOOPBACK || loopback) {
1707                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1708                 /* loop back */
1709                 skb_orphan(skb);
1710                 if (ddp->deh_dnode == ATADDR_BCAST) {
1711                         struct atalk_addr at_lo;
1712
1713                         at_lo.s_node = 0;
1714                         at_lo.s_net  = 0;
1715
1716                         rt = atrtr_find(&at_lo);
1717                         if (!rt) {
1718                                 kfree_skb(skb);
1719                                 err = -ENETUNREACH;
1720                                 goto out;
1721                         }
1722                         dev = rt->dev;
1723                         skb->dev = dev;
1724                 }
1725                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1726         } else {
1727                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1728                 if (rt->flags & RTF_GATEWAY) {
1729                     gsat.sat_addr = rt->gateway;
1730                     usat = &gsat;
1731                 }
1732
1733                 /*
1734                  * If it fails it is queued/sent above in the aarp queue
1735                  */
1736                 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1737         }
1738         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1739
1740 out:
1741         unlock_kernel();
1742         return err ? : len;
1743 }
1744
1745 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1746                          size_t size, int flags)
1747 {
1748         struct sock *sk = sock->sk;
1749         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1750         struct ddpehdr *ddp;
1751         int copied = 0;
1752         int offset = 0;
1753         int err = 0;
1754         struct sk_buff *skb;
1755
1756         lock_kernel();
1757         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1758                                                 flags & MSG_DONTWAIT, &err);
1759         if (!skb)
1760                 goto out;
1761
1762         /* FIXME: use skb->cb to be able to use shared skbs */
1763         ddp = ddp_hdr(skb);
1764         copied = ntohs(ddp->deh_len_hops) & 1023;
1765
1766         if (sk->sk_type != SOCK_RAW) {
1767                 offset = sizeof(*ddp);
1768                 copied -= offset;
1769         }
1770
1771         if (copied > size) {
1772                 copied = size;
1773                 msg->msg_flags |= MSG_TRUNC;
1774         }
1775         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1776
1777         if (!err) {
1778                 if (sat) {
1779                         sat->sat_family      = AF_APPLETALK;
1780                         sat->sat_port        = ddp->deh_sport;
1781                         sat->sat_addr.s_node = ddp->deh_snode;
1782                         sat->sat_addr.s_net  = ddp->deh_snet;
1783                 }
1784                 msg->msg_namelen = sizeof(*sat);
1785         }
1786
1787         skb_free_datagram(sk, skb);     /* Free the datagram. */
1788
1789 out:
1790         unlock_kernel();
1791         return err ? : copied;
1792 }
1793
1794
1795 /*
1796  * AppleTalk ioctl calls.
1797  */
1798 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1799 {
1800         int rc = -ENOIOCTLCMD;
1801         struct sock *sk = sock->sk;
1802         void __user *argp = (void __user *)arg;
1803
1804         switch (cmd) {
1805                 /* Protocol layer */
1806                 case TIOCOUTQ: {
1807                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1808
1809                         if (amount < 0)
1810                                 amount = 0;
1811                         rc = put_user(amount, (int __user *)argp);
1812                         break;
1813                 }
1814                 case TIOCINQ: {
1815                         /*
1816                          * These two are safe on a single CPU system as only
1817                          * user tasks fiddle here
1818                          */
1819                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1820                         long amount = 0;
1821
1822                         if (skb)
1823                                 amount = skb->len - sizeof(struct ddpehdr);
1824                         rc = put_user(amount, (int __user *)argp);
1825                         break;
1826                 }
1827                 case SIOCGSTAMP:
1828                         rc = sock_get_timestamp(sk, argp);
1829                         break;
1830                 case SIOCGSTAMPNS:
1831                         rc = sock_get_timestampns(sk, argp);
1832                         break;
1833                 /* Routing */
1834                 case SIOCADDRT:
1835                 case SIOCDELRT:
1836                         rc = -EPERM;
1837                         if (capable(CAP_NET_ADMIN))
1838                                 rc = atrtr_ioctl(cmd, argp);
1839                         break;
1840                 /* Interface */
1841                 case SIOCGIFADDR:
1842                 case SIOCSIFADDR:
1843                 case SIOCGIFBRDADDR:
1844                 case SIOCATALKDIFADDR:
1845                 case SIOCDIFADDR:
1846                 case SIOCSARP:          /* proxy AARP */
1847                 case SIOCDARP:          /* proxy AARP */
1848                         rtnl_lock();
1849                         rc = atif_ioctl(cmd, argp);
1850                         rtnl_unlock();
1851                         break;
1852         }
1853
1854         return rc;
1855 }
1856
1857
1858 #ifdef CONFIG_COMPAT
1859 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1860 {
1861         /*
1862          * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1863          * cannot handle it in common code. The data we access if ifreq
1864          * here is compatible, so we can simply call the native
1865          * handler.
1866          */
1867         if (cmd == SIOCATALKDIFADDR)
1868                 return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1869
1870         return -ENOIOCTLCMD;
1871 }
1872 #endif
1873
1874
1875 static const struct net_proto_family atalk_family_ops = {
1876         .family         = PF_APPLETALK,
1877         .create         = atalk_create,
1878         .owner          = THIS_MODULE,
1879 };
1880
1881 static const struct proto_ops atalk_dgram_ops = {
1882         .family         = PF_APPLETALK,
1883         .owner          = THIS_MODULE,
1884         .release        = atalk_release,
1885         .bind           = atalk_bind,
1886         .connect        = atalk_connect,
1887         .socketpair     = sock_no_socketpair,
1888         .accept         = sock_no_accept,
1889         .getname        = atalk_getname,
1890         .poll           = atalk_poll,
1891         .ioctl          = atalk_ioctl,
1892 #ifdef CONFIG_COMPAT
1893         .compat_ioctl   = atalk_compat_ioctl,
1894 #endif
1895         .listen         = sock_no_listen,
1896         .shutdown       = sock_no_shutdown,
1897         .setsockopt     = sock_no_setsockopt,
1898         .getsockopt     = sock_no_getsockopt,
1899         .sendmsg        = atalk_sendmsg,
1900         .recvmsg        = atalk_recvmsg,
1901         .mmap           = sock_no_mmap,
1902         .sendpage       = sock_no_sendpage,
1903 };
1904
1905 static struct notifier_block ddp_notifier = {
1906         .notifier_call  = ddp_device_event,
1907 };
1908
1909 static struct packet_type ltalk_packet_type __read_mostly = {
1910         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1911         .func           = ltalk_rcv,
1912 };
1913
1914 static struct packet_type ppptalk_packet_type __read_mostly = {
1915         .type           = cpu_to_be16(ETH_P_PPPTALK),
1916         .func           = atalk_rcv,
1917 };
1918
1919 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1920
1921 /* Export symbols for use by drivers when AppleTalk is a module */
1922 EXPORT_SYMBOL(atrtr_get_dev);
1923 EXPORT_SYMBOL(atalk_find_dev_addr);
1924
1925 static const char atalk_err_snap[] __initconst =
1926         KERN_CRIT "Unable to register DDP with SNAP.\n";
1927
1928 /* Called by proto.c on kernel start up */
1929 static int __init atalk_init(void)
1930 {
1931         int rc = proto_register(&ddp_proto, 0);
1932
1933         if (rc != 0)
1934                 goto out;
1935
1936         (void)sock_register(&atalk_family_ops);
1937         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1938         if (!ddp_dl)
1939                 printk(atalk_err_snap);
1940
1941         dev_add_pack(&ltalk_packet_type);
1942         dev_add_pack(&ppptalk_packet_type);
1943
1944         register_netdevice_notifier(&ddp_notifier);
1945         aarp_proto_init();
1946         atalk_proc_init();
1947         atalk_register_sysctl();
1948 out:
1949         return rc;
1950 }
1951 module_init(atalk_init);
1952
1953 /*
1954  * No explicit module reference count manipulation is needed in the
1955  * protocol. Socket layer sets module reference count for us
1956  * and interfaces reference counting is done
1957  * by the network device layer.
1958  *
1959  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1960  * sockets be closed from user space.
1961  */
1962 static void __exit atalk_exit(void)
1963 {
1964 #ifdef CONFIG_SYSCTL
1965         atalk_unregister_sysctl();
1966 #endif /* CONFIG_SYSCTL */
1967         atalk_proc_exit();
1968         aarp_cleanup_module();  /* General aarp clean-up. */
1969         unregister_netdevice_notifier(&ddp_notifier);
1970         dev_remove_pack(&ltalk_packet_type);
1971         dev_remove_pack(&ppptalk_packet_type);
1972         unregister_snap_client(ddp_dl);
1973         sock_unregister(PF_APPLETALK);
1974         proto_unregister(&ddp_proto);
1975 }
1976 module_exit(atalk_exit);
1977
1978 MODULE_LICENSE("GPL");
1979 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1980 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1981 MODULE_ALIAS_NETPROTO(PF_APPLETALK);