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 <net/datalink.h>
  60 #include <net/psnap.h>
  61 #include <net/sock.h>
  62 #include <net/tcp_states.h>
  63 #include <net/route.h>
  64 #include <linux/atalk.h>
  65 #include "../core/kmap_skb.h"
  66
  67 struct datalink_proto *ddp_dl, *aarp_dl;
  68 static const struct proto_ops atalk_dgram_ops;
  69
  70 /**************************************************************************\
  71 *                                                                          *
  72 * Handlers for the socket list.                                            *
  73 *                                                                          *
  74 \**************************************************************************/
  75
  76 HLIST_HEAD(atalk_sockets);
  77 DEFINE_RWLOCK(atalk_sockets_lock);
  78
  79 static inline void __atalk_insert_socket(struct sock *sk)
  80 {
  81         sk_add_node(sk, &atalk_sockets);
  82 }
  83
  84 static inline void atalk_remove_socket(struct sock *sk)
  85 {
  86         write_lock_bh(&atalk_sockets_lock);
  87         sk_del_node_init(sk);
  88         write_unlock_bh(&atalk_sockets_lock);
  89 }
  90
  91 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  92                                         struct atalk_iface *atif)
  93 {
  94         struct sock *s;
  95         struct hlist_node *node;
  96
  97         read_lock_bh(&atalk_sockets_lock);
  98         sk_for_each(s, node, &atalk_sockets) {
  99                 struct atalk_sock *at = at_sk(s);
 100
 101                 if (to->sat_port != at->src_port)
 102                         continue;
 103
 104                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 105                     to->sat_addr.s_node == ATADDR_BCAST)
 106                         goto found;
 107
 108                 if (to->sat_addr.s_net == at->src_net &&
 109                     (to->sat_addr.s_node == at->src_node ||
 110                      to->sat_addr.s_node == ATADDR_BCAST ||
 111                      to->sat_addr.s_node == ATADDR_ANYNODE))
 112                         goto found;
 113
 114                 /* XXXX.0 -- we got a request for this router. make sure
 115                  * that the node is appropriately set. */
 116                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 117                     to->sat_addr.s_net != ATADDR_ANYNET &&
 118                     atif->address.s_node == at->src_node) {
 119                         to->sat_addr.s_node = atif->address.s_node;
 120                         goto found;
 121                 }
 122         }
 123         s = NULL;
 124 found:
 125         read_unlock_bh(&atalk_sockets_lock);
 126         return s;
 127 }
 128
 129 /**
 130  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 131  * @sk - socket to insert in the list if it is not there already
 132  * @sat - address to search for
 133  *
 134  * Try to find a socket matching ADDR in the socket list, if found then return
 135  * it. If not, insert SK into the socket list.
 136  *
 137  * This entire operation must execute atomically.
 138  */
 139 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 140                                                 struct sockaddr_at *sat)
 141 {
 142         struct sock *s;
 143         struct hlist_node *node;
 144         struct atalk_sock *at;
 145
 146         write_lock_bh(&atalk_sockets_lock);
 147         sk_for_each(s, node, &atalk_sockets) {
 148                 at = at_sk(s);
 149
 150                 if (at->src_net == sat->sat_addr.s_net &&
 151                     at->src_node == sat->sat_addr.s_node &&
 152                     at->src_port == sat->sat_port)
 153                         goto found;
 154         }
 155         s = NULL;
 156         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 157 found:
 158         write_unlock_bh(&atalk_sockets_lock);
 159         return s;
 160 }
 161
 162 static void atalk_destroy_timer(unsigned long data)
 163 {
 164         struct sock *sk = (struct sock *)data;
 165
 166         if (sk_has_allocations(sk)) {
 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 (sk_has_allocations(sk)) {
 179                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
 180                                 (unsigned long)sk);
 181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 182                 add_timer(&sk->sk_timer);
 183         } else
 184                 sock_put(sk);
 185 }
 186
 187 /**************************************************************************\
 188 *                                                                          *
 189 * Routing tables for the AppleTalk socket layer.                           *
 190 *                                                                          *
 191 \**************************************************************************/
 192
 193 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 194 struct atalk_route *atalk_routes;
 195 DEFINE_RWLOCK(atalk_routes_lock);
 196
 197 struct atalk_iface *atalk_interfaces;
 198 DEFINE_RWLOCK(atalk_interfaces_lock);
 199
 200 /* For probing devices or in a routerless network */
 201 struct atalk_route atrtr_default;
 202
 203 /* AppleTalk interface control */
 204 /*
 205  * Drop a device. Doesn't drop any of its routes - that is the caller's
 206  * problem. Called when we down the interface or delete the address.
 207  */
 208 static void atif_drop_device(struct net_device *dev)
 209 {
 210         struct atalk_iface **iface = &atalk_interfaces;
 211         struct atalk_iface *tmp;
 212
 213         write_lock_bh(&atalk_interfaces_lock);
 214         while ((tmp = *iface) != NULL) {
 215                 if (tmp->dev == dev) {
 216                         *iface = tmp->next;
 217                         dev_put(dev);
 218                         kfree(tmp);
 219                         dev->atalk_ptr = NULL;
 220                 } else
 221                         iface = &tmp->next;
 222         }
 223         write_unlock_bh(&atalk_interfaces_lock);
 224 }
 225
 226 static struct atalk_iface *atif_add_device(struct net_device *dev,
 227                                            struct atalk_addr *sa)
 228 {
 229         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 230
 231         if (!iface)
 232                 goto out;
 233
 234         dev_hold(dev);
 235         iface->dev = dev;
 236         dev->atalk_ptr = iface;
 237         iface->address = *sa;
 238         iface->status = 0;
 239
 240         write_lock_bh(&atalk_interfaces_lock);
 241         iface->next = atalk_interfaces;
 242         atalk_interfaces = iface;
 243         write_unlock_bh(&atalk_interfaces_lock);
 244 out:
 245         return iface;
 246 }
 247
 248 /* Perform phase 2 AARP probing on our tentative address */
 249 static int atif_probe_device(struct atalk_iface *atif)
 250 {
 251         int netrange = ntohs(atif->nets.nr_lastnet) -
 252                         ntohs(atif->nets.nr_firstnet) + 1;
 253         int probe_net = ntohs(atif->address.s_net);
 254         int probe_node = atif->address.s_node;
 255         int netct, nodect;
 256
 257         /* Offset the network we start probing with */
 258         if (probe_net == ATADDR_ANYNET) {
 259                 probe_net = ntohs(atif->nets.nr_firstnet);
 260                 if (netrange)
 261                         probe_net += jiffies % netrange;
 262         }
 263         if (probe_node == ATADDR_ANYNODE)
 264                 probe_node = jiffies & 0xFF;
 265
 266         /* Scan the networks */
 267         atif->status |= ATIF_PROBE;
 268         for (netct = 0; netct <= netrange; netct++) {
 269                 /* Sweep the available nodes from a given start */
 270                 atif->address.s_net = htons(probe_net);
 271                 for (nodect = 0; nodect < 256; nodect++) {
 272                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 273                         if (atif->address.s_node > 0 &&
 274                             atif->address.s_node < 254) {
 275                                 /* Probe a proposed address */
 276                                 aarp_probe_network(atif);
 277
 278                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 279                                         atif->status &= ~ATIF_PROBE;
 280                                         return 0;
 281                                 }
 282                         }
 283                         atif->status &= ~ATIF_PROBE_FAIL;
 284                 }
 285                 probe_net++;
 286                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 287                         probe_net = ntohs(atif->nets.nr_firstnet);
 288         }
 289         atif->status &= ~ATIF_PROBE;
 290
 291         return -EADDRINUSE;     /* Network is full... */
 292 }
 293
 294
 295 /* Perform AARP probing for a proxy address */
 296 static int atif_proxy_probe_device(struct atalk_iface *atif,
 297                                    struct atalk_addr* proxy_addr)
 298 {
 299         int netrange = ntohs(atif->nets.nr_lastnet) -
 300                         ntohs(atif->nets.nr_firstnet) + 1;
 301         /* we probe the interface's network */
 302         int probe_net = ntohs(atif->address.s_net);
 303         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 304         int netct, nodect;
 305
 306         /* Offset the network we start probing with */
 307         if (probe_net == ATADDR_ANYNET) {
 308                 probe_net = ntohs(atif->nets.nr_firstnet);
 309                 if (netrange)
 310                         probe_net += jiffies % netrange;
 311         }
 312
 313         if (probe_node == ATADDR_ANYNODE)
 314                 probe_node = jiffies & 0xFF;
 315
 316         /* Scan the networks */
 317         for (netct = 0; netct <= netrange; netct++) {
 318                 /* Sweep the available nodes from a given start */
 319                 proxy_addr->s_net = htons(probe_net);
 320                 for (nodect = 0; nodect < 256; nodect++) {
 321                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 322                         if (proxy_addr->s_node > 0 &&
 323                             proxy_addr->s_node < 254) {
 324                                 /* Tell AARP to probe a proposed address */
 325                                 int ret = aarp_proxy_probe_network(atif,
 326                                                                     proxy_addr);
 327
 328                                 if (ret != -EADDRINUSE)
 329                                         return ret;
 330                         }
 331                 }
 332                 probe_net++;
 333                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 334                         probe_net = ntohs(atif->nets.nr_firstnet);
 335         }
 336
 337         return -EADDRINUSE;     /* Network is full... */
 338 }
 339
 340
 341 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 342 {
 343         struct atalk_iface *iface = dev->atalk_ptr;
 344         return iface ? &iface->address : NULL;
 345 }
 346
 347 static struct atalk_addr *atalk_find_primary(void)
 348 {
 349         struct atalk_iface *fiface = NULL;
 350         struct atalk_addr *retval;
 351         struct atalk_iface *iface;
 352
 353         /*
 354          * Return a point-to-point interface only if
 355          * there is no non-ptp interface available.
 356          */
 357         read_lock_bh(&atalk_interfaces_lock);
 358         for (iface = atalk_interfaces; iface; iface = iface->next) {
 359                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 360                         fiface = iface;
 361                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 362                         retval = &iface->address;
 363                         goto out;
 364                 }
 365         }
 366
 367         if (fiface)
 368                 retval = &fiface->address;
 369         else if (atalk_interfaces)
 370                 retval = &atalk_interfaces->address;
 371         else
 372                 retval = NULL;
 373 out:
 374         read_unlock_bh(&atalk_interfaces_lock);
 375         return retval;
 376 }
 377
 378 /*
 379  * Find a match for 'any network' - ie any of our interfaces with that
 380  * node number will do just nicely.
 381  */
 382 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 383 {
 384         struct atalk_iface *iface = dev->atalk_ptr;
 385
 386         if (!iface || iface->status & ATIF_PROBE)
 387                 goto out_err;
 388
 389         if (node != ATADDR_BCAST &&
 390             iface->address.s_node != node &&
 391             node != ATADDR_ANYNODE)
 392                 goto out_err;
 393 out:
 394         return iface;
 395 out_err:
 396         iface = NULL;
 397         goto out;
 398 }
 399
 400 /* Find a match for a specific network:node pair */
 401 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 402 {
 403         struct atalk_iface *iface;
 404
 405         read_lock_bh(&atalk_interfaces_lock);
 406         for (iface = atalk_interfaces; iface; iface = iface->next) {
 407                 if ((node == ATADDR_BCAST ||
 408                      node == ATADDR_ANYNODE ||
 409                      iface->address.s_node == node) &&
 410                     iface->address.s_net == net &&
 411                     !(iface->status & ATIF_PROBE))
 412                         break;
 413
 414                 /* XXXX.0 -- net.0 returns the iface associated with net */
 415                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 416                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 417                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 418                         break;
 419         }
 420         read_unlock_bh(&atalk_interfaces_lock);
 421         return iface;
 422 }
 423
 424
 425 /*
 426  * Find a route for an AppleTalk packet. This ought to get cached in
 427  * the socket (later on...). We know about host routes and the fact
 428  * that a route must be direct to broadcast.
 429  */
 430 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 431 {
 432         /*
 433          * we must search through all routes unless we find a
 434          * host route, because some host routes might overlap
 435          * network routes
 436          */
 437         struct atalk_route *net_route = NULL;
 438         struct atalk_route *r;
 439
 440         read_lock_bh(&atalk_routes_lock);
 441         for (r = atalk_routes; r; r = r->next) {
 442                 if (!(r->flags & RTF_UP))
 443                         continue;
 444
 445                 if (r->target.s_net == target->s_net) {
 446                         if (r->flags & RTF_HOST) {
 447                                 /*
 448                                  * if this host route is for the target,
 449                                  * the we're done
 450                                  */
 451                                 if (r->target.s_node == target->s_node)
 452                                         goto out;
 453                         } else
 454                                 /*
 455                                  * this route will work if there isn't a
 456                                  * direct host route, so cache it
 457                                  */
 458                                 net_route = r;
 459                 }
 460         }
 461
 462         /*
 463          * if we found a network route but not a direct host
 464          * route, then return it
 465          */
 466         if (net_route)
 467                 r = net_route;
 468         else if (atrtr_default.dev)
 469                 r = &atrtr_default;
 470         else /* No route can be found */
 471                 r = NULL;
 472 out:
 473         read_unlock_bh(&atalk_routes_lock);
 474         return r;
 475 }
 476
 477
 478 /*
 479  * Given an AppleTalk network, find the device to use. This can be
 480  * a simple lookup.
 481  */
 482 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 483 {
 484         struct atalk_route *atr = atrtr_find(sa);
 485         return atr ? atr->dev : NULL;
 486 }
 487
 488 /* Set up a default router */
 489 static void atrtr_set_default(struct net_device *dev)
 490 {
 491         atrtr_default.dev            = dev;
 492         atrtr_default.flags          = RTF_UP;
 493         atrtr_default.gateway.s_net  = htons(0);
 494         atrtr_default.gateway.s_node = 0;
 495 }
 496
 497 /*
 498  * Add a router. Basically make sure it looks valid and stuff the
 499  * entry in the list. While it uses netranges we always set them to one
 500  * entry to work like netatalk.
 501  */
 502 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 503 {
 504         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 505         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 506         struct atalk_route *rt;
 507         struct atalk_iface *iface, *riface;
 508         int retval = -EINVAL;
 509
 510         /*
 511          * Fixme: Raise/Lower a routing change semaphore for these
 512          * operations.
 513          */
 514
 515         /* Validate the request */
 516         if (ta->sat_family != AF_APPLETALK ||
 517             (!devhint && ga->sat_family != AF_APPLETALK))
 518                 goto out;
 519
 520         /* Now walk the routing table and make our decisions */
 521         write_lock_bh(&atalk_routes_lock);
 522         for (rt = atalk_routes; rt; rt = rt->next) {
 523                 if (r->rt_flags != rt->flags)
 524                         continue;
 525
 526                 if (ta->sat_addr.s_net == rt->target.s_net) {
 527                         if (!(rt->flags & RTF_HOST))
 528                                 break;
 529                         if (ta->sat_addr.s_node == rt->target.s_node)
 530                                 break;
 531                 }
 532         }
 533
 534         if (!devhint) {
 535                 riface = NULL;
 536
 537                 read_lock_bh(&atalk_interfaces_lock);
 538                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 539                         if (!riface &&
 540                             ntohs(ga->sat_addr.s_net) >=
 541                                         ntohs(iface->nets.nr_firstnet) &&
 542                             ntohs(ga->sat_addr.s_net) <=
 543                                         ntohs(iface->nets.nr_lastnet))
 544                                 riface = iface;
 545
 546                         if (ga->sat_addr.s_net == iface->address.s_net &&
 547                             ga->sat_addr.s_node == iface->address.s_node)
 548                                 riface = iface;
 549                 }
 550                 read_unlock_bh(&atalk_interfaces_lock);
 551
 552                 retval = -ENETUNREACH;
 553                 if (!riface)
 554                         goto out_unlock;
 555
 556                 devhint = riface->dev;
 557         }
 558
 559         if (!rt) {
 560                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 561
 562                 retval = -ENOBUFS;
 563                 if (!rt)
 564                         goto out_unlock;
 565
 566                 rt->next = atalk_routes;
 567                 atalk_routes = rt;
 568         }
 569
 570         /* Fill in the routing entry */
 571         rt->target  = ta->sat_addr;
 572         dev_hold(devhint);
 573         rt->dev     = devhint;
 574         rt->flags   = r->rt_flags;
 575         rt->gateway = ga->sat_addr;
 576
 577         retval = 0;
 578 out_unlock:
 579         write_unlock_bh(&atalk_routes_lock);
 580 out:
 581         return retval;
 582 }
 583
 584 /* Delete a route. Find it and discard it */
 585 static int atrtr_delete(struct atalk_addr * addr)
 586 {
 587         struct atalk_route **r = &atalk_routes;
 588         int retval = 0;
 589         struct atalk_route *tmp;
 590
 591         write_lock_bh(&atalk_routes_lock);
 592         while ((tmp = *r) != NULL) {
 593                 if (tmp->target.s_net == addr->s_net &&
 594                     (!(tmp->flags&RTF_GATEWAY) ||
 595                      tmp->target.s_node == addr->s_node)) {
 596                         *r = tmp->next;
 597                         dev_put(tmp->dev);
 598                         kfree(tmp);
 599                         goto out;
 600                 }
 601                 r = &tmp->next;
 602         }
 603         retval = -ENOENT;
 604 out:
 605         write_unlock_bh(&atalk_routes_lock);
 606         return retval;
 607 }
 608
 609 /*
 610  * Called when a device is downed. Just throw away any routes
 611  * via it.
 612  */
 613 static void atrtr_device_down(struct net_device *dev)
 614 {
 615         struct atalk_route **r = &atalk_routes;
 616         struct atalk_route *tmp;
 617
 618         write_lock_bh(&atalk_routes_lock);
 619         while ((tmp = *r) != NULL) {
 620                 if (tmp->dev == dev) {
 621                         *r = tmp->next;
 622                         dev_put(dev);
 623                         kfree(tmp);
 624                 } else
 625                         r = &tmp->next;
 626         }
 627         write_unlock_bh(&atalk_routes_lock);
 628
 629         if (atrtr_default.dev == dev)
 630                 atrtr_set_default(NULL);
 631 }
 632
 633 /* Actually down the interface */
 634 static inline void atalk_dev_down(struct net_device *dev)
 635 {
 636         atrtr_device_down(dev); /* Remove all routes for the device */
 637         aarp_device_down(dev);  /* Remove AARP entries for the device */
 638         atif_drop_device(dev);  /* Remove the device */
 639 }
 640
 641 /*
 642  * A device event has occurred. Watch for devices going down and
 643  * delete our use of them (iface and route).
 644  */
 645 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 646                             void *ptr)
 647 {
 648         struct net_device *dev = ptr;
 649
 650         if (!net_eq(dev_net(dev), &init_net))
 651                 return NOTIFY_DONE;
 652
 653         if (event == NETDEV_DOWN)
 654                 /* Discard any use of this */
 655                 atalk_dev_down(dev);
 656
 657         return NOTIFY_DONE;
 658 }
 659
 660 /* ioctl calls. Shouldn't even need touching */
 661 /* Device configuration ioctl calls */
 662 static int atif_ioctl(int cmd, void __user *arg)
 663 {
 664         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 665         struct ifreq atreq;
 666         struct atalk_netrange *nr;
 667         struct sockaddr_at *sa;
 668         struct net_device *dev;
 669         struct atalk_iface *atif;
 670         int ct;
 671         int limit;
 672         struct rtentry rtdef;
 673         int add_route;
 674
 675         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 676                 return -EFAULT;
 677
 678         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
 679         if (!dev)
 680                 return -ENODEV;
 681
 682         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 683         atif = atalk_find_dev(dev);
 684
 685         switch (cmd) {
 686                 case SIOCSIFADDR:
 687                         if (!capable(CAP_NET_ADMIN))
 688                                 return -EPERM;
 689                         if (sa->sat_family != AF_APPLETALK)
 690                                 return -EINVAL;
 691                         if (dev->type != ARPHRD_ETHER &&
 692                             dev->type != ARPHRD_LOOPBACK &&
 693                             dev->type != ARPHRD_LOCALTLK &&
 694                             dev->type != ARPHRD_PPP)
 695                                 return -EPROTONOSUPPORT;
 696
 697                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 698                         add_route = 1;
 699
 700                         /*
 701                          * if this is a point-to-point iface, and we already
 702                          * have an iface for this AppleTalk address, then we
 703                          * should not add a route
 704                          */
 705                         if ((dev->flags & IFF_POINTOPOINT) &&
 706                             atalk_find_interface(sa->sat_addr.s_net,
 707                                                  sa->sat_addr.s_node)) {
 708                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 709                                                   "interface added with "
 710                                                   "existing address\n");
 711                                 add_route = 0;
 712                         }
 713
 714                         /*
 715                          * Phase 1 is fine on LocalTalk but we don't do
 716                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 717                          */
 718                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 719                                 return -EPROTONOSUPPORT;
 720                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 721                             sa->sat_addr.s_node == 254)
 722                                 return -EINVAL;
 723                         if (atif) {
 724                                 /* Already setting address */
 725                                 if (atif->status & ATIF_PROBE)
 726                                         return -EBUSY;
 727
 728                                 atif->address.s_net  = sa->sat_addr.s_net;
 729                                 atif->address.s_node = sa->sat_addr.s_node;
 730                                 atrtr_device_down(dev); /* Flush old routes */
 731                         } else {
 732                                 atif = atif_add_device(dev, &sa->sat_addr);
 733                                 if (!atif)
 734                                         return -ENOMEM;
 735                         }
 736                         atif->nets = *nr;
 737
 738                         /*
 739                          * Check if the chosen address is used. If so we
 740                          * error and atalkd will try another.
 741                          */
 742
 743                         if (!(dev->flags & IFF_LOOPBACK) &&
 744                             !(dev->flags & IFF_POINTOPOINT) &&
 745                             atif_probe_device(atif) < 0) {
 746                                 atif_drop_device(dev);
 747                                 return -EADDRINUSE;
 748                         }
 749
 750                         /* Hey it worked - add the direct routes */
 751                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 752                         sa->sat_family = AF_APPLETALK;
 753                         sa->sat_addr.s_net  = atif->address.s_net;
 754                         sa->sat_addr.s_node = atif->address.s_node;
 755                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 756                         rtdef.rt_flags = RTF_UP;
 757                         sa->sat_family = AF_APPLETALK;
 758                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 759                         if (dev->flags & IFF_LOOPBACK ||
 760                             dev->flags & IFF_POINTOPOINT)
 761                                 rtdef.rt_flags |= RTF_HOST;
 762
 763                         /* Routerless initial state */
 764                         if (nr->nr_firstnet == htons(0) &&
 765                             nr->nr_lastnet == htons(0xFFFE)) {
 766                                 sa->sat_addr.s_net = atif->address.s_net;
 767                                 atrtr_create(&rtdef, dev);
 768                                 atrtr_set_default(dev);
 769                         } else {
 770                                 limit = ntohs(nr->nr_lastnet);
 771                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 772                                         printk(KERN_WARNING "Too many routes/"
 773                                                             "iface.\n");
 774                                         return -EINVAL;
 775                                 }
 776                                 if (add_route)
 777                                         for (ct = ntohs(nr->nr_firstnet);
 778                                              ct <= limit; ct++) {
 779                                                 sa->sat_addr.s_net = htons(ct);
 780                                                 atrtr_create(&rtdef, dev);
 781                                         }
 782                         }
 783                         dev_mc_add(dev, aarp_mcast, 6, 1);
 784                         return 0;
 785
 786                 case SIOCGIFADDR:
 787                         if (!atif)
 788                                 return -EADDRNOTAVAIL;
 789
 790                         sa->sat_family = AF_APPLETALK;
 791                         sa->sat_addr = atif->address;
 792                         break;
 793
 794                 case SIOCGIFBRDADDR:
 795                         if (!atif)
 796                                 return -EADDRNOTAVAIL;
 797
 798                         sa->sat_family = AF_APPLETALK;
 799                         sa->sat_addr.s_net = atif->address.s_net;
 800                         sa->sat_addr.s_node = ATADDR_BCAST;
 801                         break;
 802
 803                 case SIOCATALKDIFADDR:
 804                 case SIOCDIFADDR:
 805                         if (!capable(CAP_NET_ADMIN))
 806                                 return -EPERM;
 807                         if (sa->sat_family != AF_APPLETALK)
 808                                 return -EINVAL;
 809                         atalk_dev_down(dev);
 810                         break;
 811
 812                 case SIOCSARP:
 813                         if (!capable(CAP_NET_ADMIN))
 814                                 return -EPERM;
 815                         if (sa->sat_family != AF_APPLETALK)
 816                                 return -EINVAL;
 817                         /*
 818                          * for now, we only support proxy AARP on ELAP;
 819                          * we should be able to do it for LocalTalk, too.
 820                          */
 821                         if (dev->type != ARPHRD_ETHER)
 822                                 return -EPROTONOSUPPORT;
 823
 824                         /*
 825                          * atif points to the current interface on this network;
 826                          * we aren't concerned about its current status (at
 827                          * least for now), but it has all the settings about
 828                          * the network we're going to probe. Consequently, it
 829                          * must exist.
 830                          */
 831                         if (!atif)
 832                                 return -EADDRNOTAVAIL;
 833
 834                         nr = (struct atalk_netrange *)&(atif->nets);
 835                         /*
 836                          * Phase 1 is fine on Localtalk but we don't do
 837                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 838                          */
 839                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 840                                 return -EPROTONOSUPPORT;
 841
 842                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 843                             sa->sat_addr.s_node == 254)
 844                                 return -EINVAL;
 845
 846                         /*
 847                          * Check if the chosen address is used. If so we
 848                          * error and ATCP will try another.
 849                          */
 850                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 851                                 return -EADDRINUSE;
 852
 853                         /*
 854                          * We now have an address on the local network, and
 855                          * the AARP code will defend it for us until we take it
 856                          * down. We don't set up any routes right now, because
 857                          * ATCP will install them manually via SIOCADDRT.
 858                          */
 859                         break;
 860
 861                 case SIOCDARP:
 862                         if (!capable(CAP_NET_ADMIN))
 863                                 return -EPERM;
 864                         if (sa->sat_family != AF_APPLETALK)
 865                                 return -EINVAL;
 866                         if (!atif)
 867                                 return -EADDRNOTAVAIL;
 868
 869                         /* give to aarp module to remove proxy entry */
 870                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 871                         return 0;
 872         }
 873
 874         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 875 }
 876
 877 /* Routing ioctl() calls */
 878 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 879 {
 880         struct rtentry rt;
 881
 882         if (copy_from_user(&rt, arg, sizeof(rt)))
 883                 return -EFAULT;
 884
 885         switch (cmd) {
 886                 case SIOCDELRT:
 887                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 888                                 return -EINVAL;
 889                         return atrtr_delete(&((struct sockaddr_at *)
 890                                                 &rt.rt_dst)->sat_addr);
 891
 892                 case SIOCADDRT: {
 893                         struct net_device *dev = NULL;
 894                         if (rt.rt_dev) {
 895                                 char name[IFNAMSIZ];
 896                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 897                                         return -EFAULT;
 898                                 name[IFNAMSIZ-1] = '\0';
 899                                 dev = __dev_get_by_name(&init_net, name);
 900                                 if (!dev)
 901                                         return -ENODEV;
 902                         }
 903                         return atrtr_create(&rt, dev);
 904                 }
 905         }
 906         return -EINVAL;
 907 }
 908
 909 /**************************************************************************\
 910 *                                                                          *
 911 * Handling for system calls applied via the various interfaces to an       *
 912 * AppleTalk socket object.                                                 *
 913 *                                                                          *
 914 \**************************************************************************/
 915
 916 /*
 917  * Checksum: This is 'optional'. It's quite likely also a good
 918  * candidate for assembler hackery 8)
 919  */
 920 static unsigned long atalk_sum_partial(const unsigned char *data,
 921                                        int len, unsigned long sum)
 922 {
 923         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 924         while (len--) {
 925                 sum += *data;
 926                 sum <<= 1;
 927                 if (sum & 0x10000) {
 928                         sum++;
 929                         sum &= 0xffff;
 930                 }
 931                 data++;
 932         }
 933         return sum;
 934 }
 935
 936 /*  Checksum skb data --  similar to skb_checksum  */
 937 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 938                                    int len, unsigned long sum)
 939 {
 940         int start = skb_headlen(skb);
 941         struct sk_buff *frag_iter;
 942         int i, copy;
 943
 944         /* checksum stuff in header space */
 945         if ( (copy = start - offset) > 0) {
 946                 if (copy > len)
 947                         copy = len;
 948                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 949                 if ( (len -= copy) == 0)
 950                         return sum;
 951
 952                 offset += copy;
 953         }
 954
 955         /* checksum stuff in frags */
 956         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 957                 int end;
 958
 959                 WARN_ON(start > offset + len);
 960
 961                 end = start + skb_shinfo(skb)->frags[i].size;
 962                 if ((copy = end - offset) > 0) {
 963                         u8 *vaddr;
 964                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 965
 966                         if (copy > len)
 967                                 copy = len;
 968                         vaddr = kmap_skb_frag(frag);
 969                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 970                                                   offset - start, copy, sum);
 971                         kunmap_skb_frag(vaddr);
 972
 973                         if (!(len -= copy))
 974                                 return sum;
 975                         offset += copy;
 976                 }
 977                 start = end;
 978         }
 979
 980         skb_walk_frags(skb, frag_iter) {
 981                 int end;
 982
 983                 WARN_ON(start > offset + len);
 984
 985                 end = start + frag_iter->len;
 986                 if ((copy = end - offset) > 0) {
 987                         if (copy > len)
 988                                 copy = len;
 989                         sum = atalk_sum_skb(frag_iter, offset - start,
 990                                             copy, sum);
 991                         if ((len -= copy) == 0)
 992                                 return sum;
 993                         offset += copy;
 994                 }
 995                 start = end;
 996         }
 997
 998         BUG_ON(len > 0);
 999
1000         return sum;
1001 }
1002
1003 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1004 {
1005         unsigned long sum;
1006
1007         /* skip header 4 bytes */
1008         sum = atalk_sum_skb(skb, 4, len-4, 0);
1009
1010         /* Use 0xFFFF for 0. 0 itself means none */
1011         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1012 }
1013
1014 static struct proto ddp_proto = {
1015         .name     = "DDP",
1016         .owner    = THIS_MODULE,
1017         .obj_size = sizeof(struct atalk_sock),
1018 };
1019
1020 /*
1021  * Create a socket. Initialise the socket, blank the addresses
1022  * set the state.
1023  */
1024 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1025                         int kern)
1026 {
1027         struct sock *sk;
1028         int rc = -ESOCKTNOSUPPORT;
1029
1030         if (net != &init_net)
1031                 return -EAFNOSUPPORT;
1032
1033         /*
1034          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1035          * and gives you the full ELAP frame. Should be handy for CAP 8)
1036          */
1037         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1038                 goto out;
1039         rc = -ENOMEM;
1040         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1041         if (!sk)
1042                 goto out;
1043         rc = 0;
1044         sock->ops = &atalk_dgram_ops;
1045         sock_init_data(sock, sk);
1046
1047         /* Checksums on by default */
1048         sock_set_flag(sk, SOCK_ZAPPED);
1049 out:
1050         return rc;
1051 }
1052
1053 /* Free a socket. No work needed */
1054 static int atalk_release(struct socket *sock)
1055 {
1056         struct sock *sk = sock->sk;
1057
1058         lock_kernel();
1059         if (sk) {
1060                 sock_orphan(sk);
1061                 sock->sk = NULL;
1062                 atalk_destroy_socket(sk);
1063         }
1064         unlock_kernel();
1065         return 0;
1066 }
1067
1068 /**
1069  * atalk_pick_and_bind_port - Pick a source port when one is not given
1070  * @sk - socket to insert into the tables
1071  * @sat - address to search for
1072  *
1073  * Pick a source port when one is not given. If we can find a suitable free
1074  * one, we insert the socket into the tables using it.
1075  *
1076  * This whole operation must be atomic.
1077  */
1078 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1079 {
1080         int retval;
1081
1082         write_lock_bh(&atalk_sockets_lock);
1083
1084         for (sat->sat_port = ATPORT_RESERVED;
1085              sat->sat_port < ATPORT_LAST;
1086              sat->sat_port++) {
1087                 struct sock *s;
1088                 struct hlist_node *node;
1089
1090                 sk_for_each(s, node, &atalk_sockets) {
1091                         struct atalk_sock *at = at_sk(s);
1092
1093                         if (at->src_net == sat->sat_addr.s_net &&
1094                             at->src_node == sat->sat_addr.s_node &&
1095                             at->src_port == sat->sat_port)
1096                                 goto try_next_port;
1097                 }
1098
1099                 /* Wheee, it's free, assign and insert. */
1100                 __atalk_insert_socket(sk);
1101                 at_sk(sk)->src_port = sat->sat_port;
1102                 retval = 0;
1103                 goto out;
1104
1105 try_next_port:;
1106         }
1107
1108         retval = -EBUSY;
1109 out:
1110         write_unlock_bh(&atalk_sockets_lock);
1111         return retval;
1112 }
1113
1114 static int atalk_autobind(struct sock *sk)
1115 {
1116         struct atalk_sock *at = at_sk(sk);
1117         struct sockaddr_at sat;
1118         struct atalk_addr *ap = atalk_find_primary();
1119         int n = -EADDRNOTAVAIL;
1120
1121         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1122                 goto out;
1123
1124         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1125         at->src_node = sat.sat_addr.s_node = ap->s_node;
1126
1127         n = atalk_pick_and_bind_port(sk, &sat);
1128         if (!n)
1129                 sock_reset_flag(sk, SOCK_ZAPPED);
1130 out:
1131         return n;
1132 }
1133
1134 /* Set the address 'our end' of the connection */
1135 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1136 {
1137         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1138         struct sock *sk = sock->sk;
1139         struct atalk_sock *at = at_sk(sk);
1140         int err;
1141
1142         if (!sock_flag(sk, SOCK_ZAPPED) ||
1143             addr_len != sizeof(struct sockaddr_at))
1144                 return -EINVAL;
1145
1146         if (addr->sat_family != AF_APPLETALK)
1147                 return -EAFNOSUPPORT;
1148
1149         lock_kernel();
1150         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1151                 struct atalk_addr *ap = atalk_find_primary();
1152
1153                 err = -EADDRNOTAVAIL;
1154                 if (!ap)
1155                         goto out;
1156
1157                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1158                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1159         } else {
1160                 err = -EADDRNOTAVAIL;
1161                 if (!atalk_find_interface(addr->sat_addr.s_net,
1162                                           addr->sat_addr.s_node))
1163                         goto out;
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                 err = atalk_pick_and_bind_port(sk, addr);
1171
1172                 if (err < 0)
1173                         goto out;
1174         } else {
1175                 at->src_port = addr->sat_port;
1176
1177                 err = -EADDRINUSE;
1178                 if (atalk_find_or_insert_socket(sk, addr))
1179                         goto out;
1180         }
1181
1182         sock_reset_flag(sk, SOCK_ZAPPED);
1183         err = 0;
1184 out:
1185         unlock_kernel();
1186         return err;
1187 }
1188
1189 /* Set the address we talk to */
1190 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1191                          int addr_len, int flags)
1192 {
1193         struct sock *sk = sock->sk;
1194         struct atalk_sock *at = at_sk(sk);
1195         struct sockaddr_at *addr;
1196         int err;
1197
1198         sk->sk_state   = TCP_CLOSE;
1199         sock->state = SS_UNCONNECTED;
1200
1201         if (addr_len != sizeof(*addr))
1202                 return -EINVAL;
1203
1204         addr = (struct sockaddr_at *)uaddr;
1205
1206         if (addr->sat_family != AF_APPLETALK)
1207                 return -EAFNOSUPPORT;
1208
1209         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1210             !sock_flag(sk, SOCK_BROADCAST)) {
1211 #if 1
1212                 printk(KERN_WARNING "%s is broken and did not set "
1213                                     "SO_BROADCAST. It will break when 2.2 is "
1214                                     "released.\n",
1215                         current->comm);
1216 #else
1217                 return -EACCES;
1218 #endif
1219         }
1220
1221         lock_kernel();
1222         err = -EBUSY;
1223         if (sock_flag(sk, SOCK_ZAPPED))
1224                 if (atalk_autobind(sk) < 0)
1225                         goto out;
1226
1227         err = -ENETUNREACH;
1228         if (!atrtr_get_dev(&addr->sat_addr))
1229                 goto out;
1230
1231         at->dest_port = addr->sat_port;
1232         at->dest_net  = addr->sat_addr.s_net;
1233         at->dest_node = addr->sat_addr.s_node;
1234
1235         sock->state  = SS_CONNECTED;
1236         sk->sk_state = TCP_ESTABLISHED;
1237         err = 0;
1238 out:
1239         unlock_kernel();
1240         return err;
1241 }
1242
1243 /*
1244  * Find the name of an AppleTalk socket. Just copy the right
1245  * fields into the sockaddr.
1246  */
1247 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1248                          int *uaddr_len, int peer)
1249 {
1250         struct sockaddr_at sat;
1251         struct sock *sk = sock->sk;
1252         struct atalk_sock *at = at_sk(sk);
1253         int err;
1254
1255         lock_kernel();
1256         err = -ENOBUFS;
1257         if (sock_flag(sk, SOCK_ZAPPED))
1258                 if (atalk_autobind(sk) < 0)
1259                         goto out;
1260
1261         *uaddr_len = sizeof(struct sockaddr_at);
1262         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
1263
1264         if (peer) {
1265                 err = -ENOTCONN;
1266                 if (sk->sk_state != TCP_ESTABLISHED)
1267                         goto out;
1268
1269                 sat.sat_addr.s_net  = at->dest_net;
1270                 sat.sat_addr.s_node = at->dest_node;
1271                 sat.sat_port        = at->dest_port;
1272         } else {
1273                 sat.sat_addr.s_net  = at->src_net;
1274                 sat.sat_addr.s_node = at->src_node;
1275                 sat.sat_port        = at->src_port;
1276         }
1277
1278         err = 0;
1279         sat.sat_family = AF_APPLETALK;
1280         memcpy(uaddr, &sat, sizeof(sat));
1281
1282 out:
1283         unlock_kernel();
1284         return err;
1285 }
1286
1287 static unsigned int atalk_poll(struct file *file, struct socket *sock,
1288                            poll_table *wait)
1289 {
1290         int err;
1291         lock_kernel();
1292         err = datagram_poll(file, sock, wait);
1293         unlock_kernel();
1294         return err;
1295 }
1296
1297 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1298 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1299 {
1300         return skb->data[12] == 22;
1301 }
1302
1303 static int handle_ip_over_ddp(struct sk_buff *skb)
1304 {
1305         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1306         struct net_device_stats *stats;
1307
1308         /* This needs to be able to handle ipddp"N" devices */
1309         if (!dev) {
1310                 kfree_skb(skb);
1311                 return NET_RX_DROP;
1312         }
1313
1314         skb->protocol = htons(ETH_P_IP);
1315         skb_pull(skb, 13);
1316         skb->dev   = dev;
1317         skb_reset_transport_header(skb);
1318
1319         stats = netdev_priv(dev);
1320         stats->rx_packets++;
1321         stats->rx_bytes += skb->len + 13;
1322         return netif_rx(skb);  /* Send the SKB up to a higher place. */
1323 }
1324 #else
1325 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1326 #define is_ip_over_ddp(skb) 0
1327 #define handle_ip_over_ddp(skb) 0
1328 #endif
1329
1330 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1331                               struct ddpehdr *ddp, __u16 len_hops, int origlen)
1332 {
1333         struct atalk_route *rt;
1334         struct atalk_addr ta;
1335
1336         /*
1337          * Don't route multicast, etc., packets, or packets sent to "this
1338          * network"
1339          */
1340         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1341                 /*
1342                  * FIXME:
1343                  *
1344                  * Can it ever happen that a packet is from a PPP iface and
1345                  * needs to be broadcast onto the default network?
1346                  */
1347                 if (dev->type == ARPHRD_PPP)
1348                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1349                                           "packet received from PPP iface\n");
1350                 goto free_it;
1351         }
1352
1353         ta.s_net  = ddp->deh_dnet;
1354         ta.s_node = ddp->deh_dnode;
1355
1356         /* Route the packet */
1357         rt = atrtr_find(&ta);
1358         /* increment hops count */
1359         len_hops += 1 << 10;
1360         if (!rt || !(len_hops & (15 << 10)))
1361                 goto free_it;
1362
1363         /* FIXME: use skb->cb to be able to use shared skbs */
1364
1365         /*
1366          * Route goes through another gateway, so set the target to the
1367          * gateway instead.
1368          */
1369
1370         if (rt->flags & RTF_GATEWAY) {
1371                 ta.s_net  = rt->gateway.s_net;
1372                 ta.s_node = rt->gateway.s_node;
1373         }
1374
1375         /* Fix up skb->len field */
1376         skb_trim(skb, min_t(unsigned int, origlen,
1377                             (rt->dev->hard_header_len +
1378                              ddp_dl->header_length + (len_hops & 1023))));
1379
1380         /* FIXME: use skb->cb to be able to use shared skbs */
1381         ddp->deh_len_hops = htons(len_hops);
1382
1383         /*
1384          * Send the buffer onwards
1385          *
1386          * Now we must always be careful. If it's come from LocalTalk to
1387          * EtherTalk it might not fit
1388          *
1389          * Order matters here: If a packet has to be copied to make a new
1390          * headroom (rare hopefully) then it won't need unsharing.
1391          *
1392          * Note. ddp-> becomes invalid at the realloc.
1393          */
1394         if (skb_headroom(skb) < 22) {
1395                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1396                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1397                 kfree_skb(skb);
1398                 skb = nskb;
1399         } else
1400                 skb = skb_unshare(skb, GFP_ATOMIC);
1401
1402         /*
1403          * If the buffer didn't vanish into the lack of space bitbucket we can
1404          * send it.
1405          */
1406         if (skb == NULL)
1407                 goto drop;
1408
1409         if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1410                 return NET_RX_DROP;
1411         return NET_RX_SUCCESS;
1412 free_it:
1413         kfree_skb(skb);
1414 drop:
1415         return NET_RX_DROP;
1416 }
1417
1418 /**
1419  *      atalk_rcv - Receive a packet (in skb) from device dev
1420  *      @skb - packet received
1421  *      @dev - network device where the packet comes from
1422  *      @pt - packet type
1423  *
1424  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1425  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1426  *      is the DDP header, skb->len is the DDP length. The physical headers
1427  *      have been extracted. PPP should probably pass frames marked as for this
1428  *      layer.  [ie ARPHRD_ETHERTALK]
1429  */
1430 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1431                      struct packet_type *pt, struct net_device *orig_dev)
1432 {
1433         struct ddpehdr *ddp;
1434         struct sock *sock;
1435         struct atalk_iface *atif;
1436         struct sockaddr_at tosat;
1437         int origlen;
1438         __u16 len_hops;
1439
1440         if (!net_eq(dev_net(dev), &init_net))
1441                 goto drop;
1442
1443         /* Don't mangle buffer if shared */
1444         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1445                 goto out;
1446
1447         /* Size check and make sure header is contiguous */
1448         if (!pskb_may_pull(skb, sizeof(*ddp)))
1449                 goto drop;
1450
1451         ddp = ddp_hdr(skb);
1452
1453         len_hops = ntohs(ddp->deh_len_hops);
1454
1455         /* Trim buffer in case of stray trailing data */
1456         origlen = skb->len;
1457         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1458
1459         /*
1460          * Size check to see if ddp->deh_len was crap
1461          * (Otherwise we'll detonate most spectacularly
1462          * in the middle of atalk_checksum() or recvmsg()).
1463          */
1464         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1465                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1466                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1467                 goto drop;
1468         }
1469
1470         /*
1471          * Any checksums. Note we don't do htons() on this == is assumed to be
1472          * valid for net byte orders all over the networking code...
1473          */
1474         if (ddp->deh_sum &&
1475             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1476                 /* Not a valid AppleTalk frame - dustbin time */
1477                 goto drop;
1478
1479         /* Check the packet is aimed at us */
1480         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1481                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1482         else
1483                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1484
1485         if (!atif) {
1486                 /* Not ours, so we route the packet via the correct
1487                  * AppleTalk iface
1488                  */
1489                 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1490         }
1491
1492         /* if IP over DDP is not selected this code will be optimized out */
1493         if (is_ip_over_ddp(skb))
1494                 return handle_ip_over_ddp(skb);
1495         /*
1496          * Which socket - atalk_search_socket() looks for a *full match*
1497          * of the <net, node, port> tuple.
1498          */
1499         tosat.sat_addr.s_net  = ddp->deh_dnet;
1500         tosat.sat_addr.s_node = ddp->deh_dnode;
1501         tosat.sat_port        = ddp->deh_dport;
1502
1503         sock = atalk_search_socket(&tosat, atif);
1504         if (!sock) /* But not one of our sockets */
1505                 goto drop;
1506
1507         /* Queue packet (standard) */
1508         skb->sk = sock;
1509
1510         if (sock_queue_rcv_skb(sock, skb) < 0)
1511                 goto drop;
1512
1513         return NET_RX_SUCCESS;
1514
1515 drop:
1516         kfree_skb(skb);
1517 out:
1518         return NET_RX_DROP;
1519
1520 }
1521
1522 /*
1523  * Receive a LocalTalk frame. We make some demands on the caller here.
1524  * Caller must provide enough headroom on the packet to pull the short
1525  * header and append a long one.
1526  */
1527 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1528                      struct packet_type *pt, struct net_device *orig_dev)
1529 {
1530         if (!net_eq(dev_net(dev), &init_net))
1531                 goto freeit;
1532
1533         /* Expand any short form frames */
1534         if (skb_mac_header(skb)[2] == 1) {
1535                 struct ddpehdr *ddp;
1536                 /* Find our address */
1537                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1538
1539                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1540                         goto freeit;
1541
1542                 /* Don't mangle buffer if shared */
1543                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1544                         return 0;
1545
1546                 /*
1547                  * The push leaves us with a ddephdr not an shdr, and
1548                  * handily the port bytes in the right place preset.
1549                  */
1550                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1551
1552                 /* Now fill in the long header */
1553
1554                 /*
1555                  * These two first. The mac overlays the new source/dest
1556                  * network information so we MUST copy these before
1557                  * we write the network numbers !
1558                  */
1559
1560                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1561                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1562
1563                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1564                 ddp->deh_snet  = ap->s_net;
1565                 ddp->deh_sum   = 0;             /* No checksum */
1566                 /*
1567                  * Not sure about this bit...
1568                  */
1569                 /* Non routable, so force a drop if we slip up later */
1570                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1571         }
1572         skb_reset_transport_header(skb);
1573
1574         return atalk_rcv(skb, dev, pt, orig_dev);
1575 freeit:
1576         kfree_skb(skb);
1577         return 0;
1578 }
1579
1580 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1581                          size_t len)
1582 {
1583         struct sock *sk = sock->sk;
1584         struct atalk_sock *at = at_sk(sk);
1585         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1586         int flags = msg->msg_flags;
1587         int loopback = 0;
1588         struct sockaddr_at local_satalk, gsat;
1589         struct sk_buff *skb;
1590         struct net_device *dev;
1591         struct ddpehdr *ddp;
1592         int size;
1593         struct atalk_route *rt;
1594         int err;
1595
1596         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1597                 return -EINVAL;
1598
1599         if (len > DDP_MAXSZ)
1600                 return -EMSGSIZE;
1601
1602         lock_kernel();
1603         if (usat) {
1604                 err = -EBUSY;
1605                 if (sock_flag(sk, SOCK_ZAPPED))
1606                         if (atalk_autobind(sk) < 0)
1607                                 goto out;
1608
1609                 err = -EINVAL;
1610                 if (msg->msg_namelen < sizeof(*usat) ||
1611                     usat->sat_family != AF_APPLETALK)
1612                         goto out;
1613
1614                 err = -EPERM;
1615                 /* netatalk didn't implement this check */
1616                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1617                     !sock_flag(sk, SOCK_BROADCAST)) {
1618                         goto out;
1619                 }
1620         } else {
1621                 err = -ENOTCONN;
1622                 if (sk->sk_state != TCP_ESTABLISHED)
1623                         goto out;
1624                 usat = &local_satalk;
1625                 usat->sat_family      = AF_APPLETALK;
1626                 usat->sat_port        = at->dest_port;
1627                 usat->sat_addr.s_node = at->dest_node;
1628                 usat->sat_addr.s_net  = at->dest_net;
1629         }
1630
1631         /* Build a packet */
1632         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1633
1634         /* For headers */
1635         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1636
1637         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1638                 rt = atrtr_find(&usat->sat_addr);
1639         } else {
1640                 struct atalk_addr at_hint;
1641
1642                 at_hint.s_node = 0;
1643                 at_hint.s_net  = at->src_net;
1644
1645                 rt = atrtr_find(&at_hint);
1646         }
1647         err = ENETUNREACH;
1648         if (!rt)
1649                 goto out;
1650
1651         dev = rt->dev;
1652
1653         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1654                         sk, size, dev->name);
1655
1656         size += dev->hard_header_len;
1657         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1658         if (!skb)
1659                 goto out;
1660
1661         skb->sk = sk;
1662         skb_reserve(skb, ddp_dl->header_length);
1663         skb_reserve(skb, dev->hard_header_len);
1664         skb->dev = dev;
1665
1666         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1667
1668         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1669         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1670         ddp->deh_dnet  = usat->sat_addr.s_net;
1671         ddp->deh_snet  = at->src_net;
1672         ddp->deh_dnode = usat->sat_addr.s_node;
1673         ddp->deh_snode = at->src_node;
1674         ddp->deh_dport = usat->sat_port;
1675         ddp->deh_sport = at->src_port;
1676
1677         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1678
1679         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1680         if (err) {
1681                 kfree_skb(skb);
1682                 err = -EFAULT;
1683                 goto out;
1684         }
1685
1686         if (sk->sk_no_check == 1)
1687                 ddp->deh_sum = 0;
1688         else
1689                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1690
1691         /*
1692          * Loopback broadcast packets to non gateway targets (ie routes
1693          * to group we are in)
1694          */
1695         if (ddp->deh_dnode == ATADDR_BCAST &&
1696             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1697                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1698
1699                 if (skb2) {
1700                         loopback = 1;
1701                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1702                         /*
1703                          * If it fails it is queued/sent above in the aarp queue
1704                          */
1705                         aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1706                 }
1707         }
1708
1709         if (dev->flags & IFF_LOOPBACK || loopback) {
1710                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1711                 /* loop back */
1712                 skb_orphan(skb);
1713                 if (ddp->deh_dnode == ATADDR_BCAST) {
1714                         struct atalk_addr at_lo;
1715
1716                         at_lo.s_node = 0;
1717                         at_lo.s_net  = 0;
1718
1719                         rt = atrtr_find(&at_lo);
1720                         if (!rt) {
1721                                 kfree_skb(skb);
1722                                 err = -ENETUNREACH;
1723                                 goto out;
1724                         }
1725                         dev = rt->dev;
1726                         skb->dev = dev;
1727                 }
1728                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1729         } else {
1730                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1731                 if (rt->flags & RTF_GATEWAY) {
1732                     gsat.sat_addr = rt->gateway;
1733                     usat = &gsat;
1734                 }
1735
1736                 /*
1737                  * If it fails it is queued/sent above in the aarp queue
1738                  */
1739                 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1740         }
1741         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1742
1743 out:
1744         unlock_kernel();
1745         return err ? : len;
1746 }
1747
1748 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1749                          size_t size, int flags)
1750 {
1751         struct sock *sk = sock->sk;
1752         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1753         struct ddpehdr *ddp;
1754         int copied = 0;
1755         int offset = 0;
1756         int err = 0;
1757         struct sk_buff *skb;
1758
1759         lock_kernel();
1760         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1761                                                 flags & MSG_DONTWAIT, &err);
1762         if (!skb)
1763                 goto out;
1764
1765         /* FIXME: use skb->cb to be able to use shared skbs */
1766         ddp = ddp_hdr(skb);
1767         copied = ntohs(ddp->deh_len_hops) & 1023;
1768
1769         if (sk->sk_type != SOCK_RAW) {
1770                 offset = sizeof(*ddp);
1771                 copied -= offset;
1772         }
1773
1774         if (copied > size) {
1775                 copied = size;
1776                 msg->msg_flags |= MSG_TRUNC;
1777         }
1778         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1779
1780         if (!err) {
1781                 if (sat) {
1782                         sat->sat_family      = AF_APPLETALK;
1783                         sat->sat_port        = ddp->deh_sport;
1784                         sat->sat_addr.s_node = ddp->deh_snode;
1785                         sat->sat_addr.s_net  = ddp->deh_snet;
1786                 }
1787                 msg->msg_namelen = sizeof(*sat);
1788         }
1789
1790         skb_free_datagram(sk, skb);     /* Free the datagram. */
1791
1792 out:
1793         unlock_kernel();
1794         return err ? : copied;
1795 }
1796
1797
1798 /*
1799  * AppleTalk ioctl calls.
1800  */
1801 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1802 {
1803         int rc = -ENOIOCTLCMD;
1804         struct sock *sk = sock->sk;
1805         void __user *argp = (void __user *)arg;
1806
1807         switch (cmd) {
1808                 /* Protocol layer */
1809                 case TIOCOUTQ: {
1810                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1811
1812                         if (amount < 0)
1813                                 amount = 0;
1814                         rc = put_user(amount, (int __user *)argp);
1815                         break;
1816                 }
1817                 case TIOCINQ: {
1818                         /*
1819                          * These two are safe on a single CPU system as only
1820                          * user tasks fiddle here
1821                          */
1822                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1823                         long amount = 0;
1824
1825                         if (skb)
1826                                 amount = skb->len - sizeof(struct ddpehdr);
1827                         rc = put_user(amount, (int __user *)argp);
1828                         break;
1829                 }
1830                 case SIOCGSTAMP:
1831                         rc = sock_get_timestamp(sk, argp);
1832                         break;
1833                 case SIOCGSTAMPNS:
1834                         rc = sock_get_timestampns(sk, argp);
1835                         break;
1836                 /* Routing */
1837                 case SIOCADDRT:
1838                 case SIOCDELRT:
1839                         rc = -EPERM;
1840                         if (capable(CAP_NET_ADMIN))
1841                                 rc = atrtr_ioctl(cmd, argp);
1842                         break;
1843                 /* Interface */
1844                 case SIOCGIFADDR:
1845                 case SIOCSIFADDR:
1846                 case SIOCGIFBRDADDR:
1847                 case SIOCATALKDIFADDR:
1848                 case SIOCDIFADDR:
1849                 case SIOCSARP:          /* proxy AARP */
1850                 case SIOCDARP:          /* proxy AARP */
1851                         rtnl_lock();
1852                         rc = atif_ioctl(cmd, argp);
1853                         rtnl_unlock();
1854                         break;
1855         }
1856
1857         return rc;
1858 }
1859
1860
1861 #ifdef CONFIG_COMPAT
1862 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1863 {
1864         /*
1865          * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1866          * cannot handle it in common code. The data we access if ifreq
1867          * here is compatible, so we can simply call the native
1868          * handler.
1869          */
1870         if (cmd == SIOCATALKDIFADDR)
1871                 return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1872
1873         return -ENOIOCTLCMD;
1874 }
1875 #endif
1876
1877
1878 static const struct net_proto_family atalk_family_ops = {
1879         .family         = PF_APPLETALK,
1880         .create         = atalk_create,
1881         .owner          = THIS_MODULE,
1882 };
1883
1884 static const struct proto_ops atalk_dgram_ops = {
1885         .family         = PF_APPLETALK,
1886         .owner          = THIS_MODULE,
1887         .release        = atalk_release,
1888         .bind           = atalk_bind,
1889         .connect        = atalk_connect,
1890         .socketpair     = sock_no_socketpair,
1891         .accept         = sock_no_accept,
1892         .getname        = atalk_getname,
1893         .poll           = atalk_poll,
1894         .ioctl          = atalk_ioctl,
1895 #ifdef CONFIG_COMPAT
1896         .compat_ioctl   = atalk_compat_ioctl,
1897 #endif
1898         .listen         = sock_no_listen,
1899         .shutdown       = sock_no_shutdown,
1900         .setsockopt     = sock_no_setsockopt,
1901         .getsockopt     = sock_no_getsockopt,
1902         .sendmsg        = atalk_sendmsg,
1903         .recvmsg        = atalk_recvmsg,
1904         .mmap           = sock_no_mmap,
1905         .sendpage       = sock_no_sendpage,
1906 };
1907
1908 static struct notifier_block ddp_notifier = {
1909         .notifier_call  = ddp_device_event,
1910 };
1911
1912 static struct packet_type ltalk_packet_type __read_mostly = {
1913         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1914         .func           = ltalk_rcv,
1915 };
1916
1917 static struct packet_type ppptalk_packet_type __read_mostly = {
1918         .type           = cpu_to_be16(ETH_P_PPPTALK),
1919         .func           = atalk_rcv,
1920 };
1921
1922 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1923
1924 /* Export symbols for use by drivers when AppleTalk is a module */
1925 EXPORT_SYMBOL(atrtr_get_dev);
1926 EXPORT_SYMBOL(atalk_find_dev_addr);
1927
1928 static const char atalk_err_snap[] __initconst =
1929         KERN_CRIT "Unable to register DDP with SNAP.\n";
1930
1931 /* Called by proto.c on kernel start up */
1932 static int __init atalk_init(void)
1933 {
1934         int rc = proto_register(&ddp_proto, 0);
1935
1936         if (rc != 0)
1937                 goto out;
1938
1939         (void)sock_register(&atalk_family_ops);
1940         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1941         if (!ddp_dl)
1942                 printk(atalk_err_snap);
1943
1944         dev_add_pack(&ltalk_packet_type);
1945         dev_add_pack(&ppptalk_packet_type);
1946
1947         register_netdevice_notifier(&ddp_notifier);
1948         aarp_proto_init();
1949         atalk_proc_init();
1950         atalk_register_sysctl();
1951 out:
1952         return rc;
1953 }
1954 module_init(atalk_init);
1955
1956 /*
1957  * No explicit module reference count manipulation is needed in the
1958  * protocol. Socket layer sets module reference count for us
1959  * and interfaces reference counting is done
1960  * by the network device layer.
1961  *
1962  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1963  * sockets be closed from user space.
1964  */
1965 static void __exit atalk_exit(void)
1966 {
1967 #ifdef CONFIG_SYSCTL
1968         atalk_unregister_sysctl();
1969 #endif /* CONFIG_SYSCTL */
1970         atalk_proc_exit();
1971         aarp_cleanup_module();  /* General aarp clean-up. */
1972         unregister_netdevice_notifier(&ddp_notifier);
1973         dev_remove_pack(&ltalk_packet_type);
1974         dev_remove_pack(&ppptalk_packet_type);
1975         unregister_snap_client(ddp_dl);
1976         sock_unregister(PF_APPLETALK);
1977         proto_unregister(&ddp_proto);
1978 }
1979 module_exit(atalk_exit);
1980
1981 MODULE_LICENSE("GPL");
1982 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1983 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1984 MODULE_ALIAS_NETPROTO(PF_APPLETALK);