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 {
1026         struct sock *sk;
1027         int rc = -ESOCKTNOSUPPORT;
1028
1029         if (net != &init_net)
1030                 return -EAFNOSUPPORT;
1031
1032         /*
1033          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1034          * and gives you the full ELAP frame. Should be handy for CAP 8)
1035          */
1036         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1037                 goto out;
1038         rc = -ENOMEM;
1039         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1040         if (!sk)
1041                 goto out;
1042         rc = 0;
1043         sock->ops = &atalk_dgram_ops;
1044         sock_init_data(sock, sk);
1045
1046         /* Checksums on by default */
1047         sock_set_flag(sk, SOCK_ZAPPED);
1048 out:
1049         return rc;
1050 }
1051
1052 /* Free a socket. No work needed */
1053 static int atalk_release(struct socket *sock)
1054 {
1055         struct sock *sk = sock->sk;
1056
1057         if (sk) {
1058                 sock_orphan(sk);
1059                 sock->sk = NULL;
1060                 atalk_destroy_socket(sk);
1061         }
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
1138         if (!sock_flag(sk, SOCK_ZAPPED) ||
1139             addr_len != sizeof(struct sockaddr_at))
1140                 return -EINVAL;
1141
1142         if (addr->sat_family != AF_APPLETALK)
1143                 return -EAFNOSUPPORT;
1144
1145         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1146                 struct atalk_addr *ap = atalk_find_primary();
1147
1148                 if (!ap)
1149                         return -EADDRNOTAVAIL;
1150
1151                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1152                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1153         } else {
1154                 if (!atalk_find_interface(addr->sat_addr.s_net,
1155                                           addr->sat_addr.s_node))
1156                         return -EADDRNOTAVAIL;
1157
1158                 at->src_net  = addr->sat_addr.s_net;
1159                 at->src_node = addr->sat_addr.s_node;
1160         }
1161
1162         if (addr->sat_port == ATADDR_ANYPORT) {
1163                 int n = atalk_pick_and_bind_port(sk, addr);
1164
1165                 if (n < 0)
1166                         return n;
1167         } else {
1168                 at->src_port = addr->sat_port;
1169
1170                 if (atalk_find_or_insert_socket(sk, addr))
1171                         return -EADDRINUSE;
1172         }
1173
1174         sock_reset_flag(sk, SOCK_ZAPPED);
1175         return 0;
1176 }
1177
1178 /* Set the address we talk to */
1179 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1180                          int addr_len, int flags)
1181 {
1182         struct sock *sk = sock->sk;
1183         struct atalk_sock *at = at_sk(sk);
1184         struct sockaddr_at *addr;
1185
1186         sk->sk_state   = TCP_CLOSE;
1187         sock->state = SS_UNCONNECTED;
1188
1189         if (addr_len != sizeof(*addr))
1190                 return -EINVAL;
1191
1192         addr = (struct sockaddr_at *)uaddr;
1193
1194         if (addr->sat_family != AF_APPLETALK)
1195                 return -EAFNOSUPPORT;
1196
1197         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1198             !sock_flag(sk, SOCK_BROADCAST)) {
1199 #if 1
1200                 printk(KERN_WARNING "%s is broken and did not set "
1201                                     "SO_BROADCAST. It will break when 2.2 is "
1202                                     "released.\n",
1203                         current->comm);
1204 #else
1205                 return -EACCES;
1206 #endif
1207         }
1208
1209         if (sock_flag(sk, SOCK_ZAPPED))
1210                 if (atalk_autobind(sk) < 0)
1211                         return -EBUSY;
1212
1213         if (!atrtr_get_dev(&addr->sat_addr))
1214                 return -ENETUNREACH;
1215
1216         at->dest_port = addr->sat_port;
1217         at->dest_net  = addr->sat_addr.s_net;
1218         at->dest_node = addr->sat_addr.s_node;
1219
1220         sock->state  = SS_CONNECTED;
1221         sk->sk_state = TCP_ESTABLISHED;
1222         return 0;
1223 }
1224
1225 /*
1226  * Find the name of an AppleTalk socket. Just copy the right
1227  * fields into the sockaddr.
1228  */
1229 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1230                          int *uaddr_len, int peer)
1231 {
1232         struct sockaddr_at sat;
1233         struct sock *sk = sock->sk;
1234         struct atalk_sock *at = at_sk(sk);
1235
1236         if (sock_flag(sk, SOCK_ZAPPED))
1237                 if (atalk_autobind(sk) < 0)
1238                         return -ENOBUFS;
1239
1240         *uaddr_len = sizeof(struct sockaddr_at);
1241         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
1242
1243         if (peer) {
1244                 if (sk->sk_state != TCP_ESTABLISHED)
1245                         return -ENOTCONN;
1246
1247                 sat.sat_addr.s_net  = at->dest_net;
1248                 sat.sat_addr.s_node = at->dest_node;
1249                 sat.sat_port        = at->dest_port;
1250         } else {
1251                 sat.sat_addr.s_net  = at->src_net;
1252                 sat.sat_addr.s_node = at->src_node;
1253                 sat.sat_port        = at->src_port;
1254         }
1255
1256         sat.sat_family = AF_APPLETALK;
1257         memcpy(uaddr, &sat, sizeof(sat));
1258         return 0;
1259 }
1260
1261 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1262 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1263 {
1264         return skb->data[12] == 22;
1265 }
1266
1267 static int handle_ip_over_ddp(struct sk_buff *skb)
1268 {
1269         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1270         struct net_device_stats *stats;
1271
1272         /* This needs to be able to handle ipddp"N" devices */
1273         if (!dev)
1274                 return -ENODEV;
1275
1276         skb->protocol = htons(ETH_P_IP);
1277         skb_pull(skb, 13);
1278         skb->dev   = dev;
1279         skb_reset_transport_header(skb);
1280
1281         stats = netdev_priv(dev);
1282         stats->rx_packets++;
1283         stats->rx_bytes += skb->len + 13;
1284         netif_rx(skb);  /* Send the SKB up to a higher place. */
1285         return 0;
1286 }
1287 #else
1288 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1289 #define is_ip_over_ddp(skb) 0
1290 #define handle_ip_over_ddp(skb) 0
1291 #endif
1292
1293 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1294                                struct ddpehdr *ddp, __u16 len_hops,
1295                                int origlen)
1296 {
1297         struct atalk_route *rt;
1298         struct atalk_addr ta;
1299
1300         /*
1301          * Don't route multicast, etc., packets, or packets sent to "this
1302          * network"
1303          */
1304         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1305                 /*
1306                  * FIXME:
1307                  *
1308                  * Can it ever happen that a packet is from a PPP iface and
1309                  * needs to be broadcast onto the default network?
1310                  */
1311                 if (dev->type == ARPHRD_PPP)
1312                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1313                                           "packet received from PPP iface\n");
1314                 goto free_it;
1315         }
1316
1317         ta.s_net  = ddp->deh_dnet;
1318         ta.s_node = ddp->deh_dnode;
1319
1320         /* Route the packet */
1321         rt = atrtr_find(&ta);
1322         /* increment hops count */
1323         len_hops += 1 << 10;
1324         if (!rt || !(len_hops & (15 << 10)))
1325                 goto free_it;
1326
1327         /* FIXME: use skb->cb to be able to use shared skbs */
1328
1329         /*
1330          * Route goes through another gateway, so set the target to the
1331          * gateway instead.
1332          */
1333
1334         if (rt->flags & RTF_GATEWAY) {
1335                 ta.s_net  = rt->gateway.s_net;
1336                 ta.s_node = rt->gateway.s_node;
1337         }
1338
1339         /* Fix up skb->len field */
1340         skb_trim(skb, min_t(unsigned int, origlen,
1341                             (rt->dev->hard_header_len +
1342                              ddp_dl->header_length + (len_hops & 1023))));
1343
1344         /* FIXME: use skb->cb to be able to use shared skbs */
1345         ddp->deh_len_hops = htons(len_hops);
1346
1347         /*
1348          * Send the buffer onwards
1349          *
1350          * Now we must always be careful. If it's come from LocalTalk to
1351          * EtherTalk it might not fit
1352          *
1353          * Order matters here: If a packet has to be copied to make a new
1354          * headroom (rare hopefully) then it won't need unsharing.
1355          *
1356          * Note. ddp-> becomes invalid at the realloc.
1357          */
1358         if (skb_headroom(skb) < 22) {
1359                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1360                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1361                 kfree_skb(skb);
1362                 if (!nskb)
1363                         goto out;
1364                 skb = nskb;
1365         } else
1366                 skb = skb_unshare(skb, GFP_ATOMIC);
1367
1368         /*
1369          * If the buffer didn't vanish into the lack of space bitbucket we can
1370          * send it.
1371          */
1372         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1373                 goto free_it;
1374 out:
1375         return;
1376 free_it:
1377         kfree_skb(skb);
1378 }
1379
1380 /**
1381  *      atalk_rcv - Receive a packet (in skb) from device dev
1382  *      @skb - packet received
1383  *      @dev - network device where the packet comes from
1384  *      @pt - packet type
1385  *
1386  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1387  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1388  *      is the DDP header, skb->len is the DDP length. The physical headers
1389  *      have been extracted. PPP should probably pass frames marked as for this
1390  *      layer.  [ie ARPHRD_ETHERTALK]
1391  */
1392 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1393                      struct packet_type *pt, struct net_device *orig_dev)
1394 {
1395         struct ddpehdr *ddp;
1396         struct sock *sock;
1397         struct atalk_iface *atif;
1398         struct sockaddr_at tosat;
1399         int origlen;
1400         __u16 len_hops;
1401
1402         if (!net_eq(dev_net(dev), &init_net))
1403                 goto freeit;
1404
1405         /* Don't mangle buffer if shared */
1406         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1407                 goto out;
1408
1409         /* Size check and make sure header is contiguous */
1410         if (!pskb_may_pull(skb, sizeof(*ddp)))
1411                 goto freeit;
1412
1413         ddp = ddp_hdr(skb);
1414
1415         len_hops = ntohs(ddp->deh_len_hops);
1416
1417         /* Trim buffer in case of stray trailing data */
1418         origlen = skb->len;
1419         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1420
1421         /*
1422          * Size check to see if ddp->deh_len was crap
1423          * (Otherwise we'll detonate most spectacularly
1424          * in the middle of atalk_checksum() or recvmsg()).
1425          */
1426         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1427                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1428                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1429                 goto freeit;
1430         }
1431
1432         /*
1433          * Any checksums. Note we don't do htons() on this == is assumed to be
1434          * valid for net byte orders all over the networking code...
1435          */
1436         if (ddp->deh_sum &&
1437             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1438                 /* Not a valid AppleTalk frame - dustbin time */
1439                 goto freeit;
1440
1441         /* Check the packet is aimed at us */
1442         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1443                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1444         else
1445                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1446
1447         if (!atif) {
1448                 /* Not ours, so we route the packet via the correct
1449                  * AppleTalk iface
1450                  */
1451                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1452                 goto out;
1453         }
1454
1455         /* if IP over DDP is not selected this code will be optimized out */
1456         if (is_ip_over_ddp(skb))
1457                 return handle_ip_over_ddp(skb);
1458         /*
1459          * Which socket - atalk_search_socket() looks for a *full match*
1460          * of the <net, node, port> tuple.
1461          */
1462         tosat.sat_addr.s_net  = ddp->deh_dnet;
1463         tosat.sat_addr.s_node = ddp->deh_dnode;
1464         tosat.sat_port        = ddp->deh_dport;
1465
1466         sock = atalk_search_socket(&tosat, atif);
1467         if (!sock) /* But not one of our sockets */
1468                 goto freeit;
1469
1470         /* Queue packet (standard) */
1471         skb->sk = sock;
1472
1473         if (sock_queue_rcv_skb(sock, skb) < 0)
1474                 goto freeit;
1475 out:
1476         return 0;
1477 freeit:
1478         kfree_skb(skb);
1479         goto out;
1480 }
1481
1482 /*
1483  * Receive a LocalTalk frame. We make some demands on the caller here.
1484  * Caller must provide enough headroom on the packet to pull the short
1485  * header and append a long one.
1486  */
1487 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1488                      struct packet_type *pt, struct net_device *orig_dev)
1489 {
1490         if (!net_eq(dev_net(dev), &init_net))
1491                 goto freeit;
1492
1493         /* Expand any short form frames */
1494         if (skb_mac_header(skb)[2] == 1) {
1495                 struct ddpehdr *ddp;
1496                 /* Find our address */
1497                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1498
1499                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1500                         goto freeit;
1501
1502                 /* Don't mangle buffer if shared */
1503                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1504                         return 0;
1505
1506                 /*
1507                  * The push leaves us with a ddephdr not an shdr, and
1508                  * handily the port bytes in the right place preset.
1509                  */
1510                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1511
1512                 /* Now fill in the long header */
1513
1514                 /*
1515                  * These two first. The mac overlays the new source/dest
1516                  * network information so we MUST copy these before
1517                  * we write the network numbers !
1518                  */
1519
1520                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1521                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1522
1523                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1524                 ddp->deh_snet  = ap->s_net;
1525                 ddp->deh_sum   = 0;             /* No checksum */
1526                 /*
1527                  * Not sure about this bit...
1528                  */
1529                 /* Non routable, so force a drop if we slip up later */
1530                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1531         }
1532         skb_reset_transport_header(skb);
1533
1534         return atalk_rcv(skb, dev, pt, orig_dev);
1535 freeit:
1536         kfree_skb(skb);
1537         return 0;
1538 }
1539
1540 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1541                          size_t len)
1542 {
1543         struct sock *sk = sock->sk;
1544         struct atalk_sock *at = at_sk(sk);
1545         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1546         int flags = msg->msg_flags;
1547         int loopback = 0;
1548         struct sockaddr_at local_satalk, gsat;
1549         struct sk_buff *skb;
1550         struct net_device *dev;
1551         struct ddpehdr *ddp;
1552         int size;
1553         struct atalk_route *rt;
1554         int err;
1555
1556         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1557                 return -EINVAL;
1558
1559         if (len > DDP_MAXSZ)
1560                 return -EMSGSIZE;
1561
1562         if (usat) {
1563                 if (sock_flag(sk, SOCK_ZAPPED))
1564                         if (atalk_autobind(sk) < 0)
1565                                 return -EBUSY;
1566
1567                 if (msg->msg_namelen < sizeof(*usat) ||
1568                     usat->sat_family != AF_APPLETALK)
1569                         return -EINVAL;
1570
1571                 /* netatalk didn't implement this check */
1572                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1573                     !sock_flag(sk, SOCK_BROADCAST)) {
1574                         return -EPERM;
1575                 }
1576         } else {
1577                 if (sk->sk_state != TCP_ESTABLISHED)
1578                         return -ENOTCONN;
1579                 usat = &local_satalk;
1580                 usat->sat_family      = AF_APPLETALK;
1581                 usat->sat_port        = at->dest_port;
1582                 usat->sat_addr.s_node = at->dest_node;
1583                 usat->sat_addr.s_net  = at->dest_net;
1584         }
1585
1586         /* Build a packet */
1587         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1588
1589         /* For headers */
1590         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1591
1592         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1593                 rt = atrtr_find(&usat->sat_addr);
1594         } else {
1595                 struct atalk_addr at_hint;
1596
1597                 at_hint.s_node = 0;
1598                 at_hint.s_net  = at->src_net;
1599
1600                 rt = atrtr_find(&at_hint);
1601         }
1602         if (!rt)
1603                 return -ENETUNREACH;
1604
1605         dev = rt->dev;
1606
1607         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1608                         sk, size, dev->name);
1609
1610         size += dev->hard_header_len;
1611         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1612         if (!skb)
1613                 return err;
1614
1615         skb->sk = sk;
1616         skb_reserve(skb, ddp_dl->header_length);
1617         skb_reserve(skb, dev->hard_header_len);
1618         skb->dev = dev;
1619
1620         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1621
1622         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1623         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1624         ddp->deh_dnet  = usat->sat_addr.s_net;
1625         ddp->deh_snet  = at->src_net;
1626         ddp->deh_dnode = usat->sat_addr.s_node;
1627         ddp->deh_snode = at->src_node;
1628         ddp->deh_dport = usat->sat_port;
1629         ddp->deh_sport = at->src_port;
1630
1631         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1632
1633         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1634         if (err) {
1635                 kfree_skb(skb);
1636                 return -EFAULT;
1637         }
1638
1639         if (sk->sk_no_check == 1)
1640                 ddp->deh_sum = 0;
1641         else
1642                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1643
1644         /*
1645          * Loopback broadcast packets to non gateway targets (ie routes
1646          * to group we are in)
1647          */
1648         if (ddp->deh_dnode == ATADDR_BCAST &&
1649             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1650                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1651
1652                 if (skb2) {
1653                         loopback = 1;
1654                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1655                         if (aarp_send_ddp(dev, skb2,
1656                                           &usat->sat_addr, NULL) == -1)
1657                                 kfree_skb(skb2);
1658                                 /* else queued/sent above in the aarp queue */
1659                 }
1660         }
1661
1662         if (dev->flags & IFF_LOOPBACK || loopback) {
1663                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1664                 /* loop back */
1665                 skb_orphan(skb);
1666                 if (ddp->deh_dnode == ATADDR_BCAST) {
1667                         struct atalk_addr at_lo;
1668
1669                         at_lo.s_node = 0;
1670                         at_lo.s_net  = 0;
1671
1672                         rt = atrtr_find(&at_lo);
1673                         if (!rt) {
1674                                 kfree_skb(skb);
1675                                 return -ENETUNREACH;
1676                         }
1677                         dev = rt->dev;
1678                         skb->dev = dev;
1679                 }
1680                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1681         } else {
1682                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1683                 if (rt->flags & RTF_GATEWAY) {
1684                     gsat.sat_addr = rt->gateway;
1685                     usat = &gsat;
1686                 }
1687
1688                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1689                         kfree_skb(skb);
1690                 /* else queued/sent above in the aarp queue */
1691         }
1692         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1693
1694         return len;
1695 }
1696
1697 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1698                          size_t size, int flags)
1699 {
1700         struct sock *sk = sock->sk;
1701         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1702         struct ddpehdr *ddp;
1703         int copied = 0;
1704         int offset = 0;
1705         int err = 0;
1706         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1707                                                 flags & MSG_DONTWAIT, &err);
1708         if (!skb)
1709                 return err;
1710
1711         /* FIXME: use skb->cb to be able to use shared skbs */
1712         ddp = ddp_hdr(skb);
1713         copied = ntohs(ddp->deh_len_hops) & 1023;
1714
1715         if (sk->sk_type != SOCK_RAW) {
1716                 offset = sizeof(*ddp);
1717                 copied -= offset;
1718         }
1719
1720         if (copied > size) {
1721                 copied = size;
1722                 msg->msg_flags |= MSG_TRUNC;
1723         }
1724         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1725
1726         if (!err) {
1727                 if (sat) {
1728                         sat->sat_family      = AF_APPLETALK;
1729                         sat->sat_port        = ddp->deh_sport;
1730                         sat->sat_addr.s_node = ddp->deh_snode;
1731                         sat->sat_addr.s_net  = ddp->deh_snet;
1732                 }
1733                 msg->msg_namelen = sizeof(*sat);
1734         }
1735
1736         skb_free_datagram(sk, skb);     /* Free the datagram. */
1737         return err ? : copied;
1738 }
1739
1740
1741 /*
1742  * AppleTalk ioctl calls.
1743  */
1744 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1745 {
1746         int rc = -ENOIOCTLCMD;
1747         struct sock *sk = sock->sk;
1748         void __user *argp = (void __user *)arg;
1749
1750         switch (cmd) {
1751                 /* Protocol layer */
1752                 case TIOCOUTQ: {
1753                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1754
1755                         if (amount < 0)
1756                                 amount = 0;
1757                         rc = put_user(amount, (int __user *)argp);
1758                         break;
1759                 }
1760                 case TIOCINQ: {
1761                         /*
1762                          * These two are safe on a single CPU system as only
1763                          * user tasks fiddle here
1764                          */
1765                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1766                         long amount = 0;
1767
1768                         if (skb)
1769                                 amount = skb->len - sizeof(struct ddpehdr);
1770                         rc = put_user(amount, (int __user *)argp);
1771                         break;
1772                 }
1773                 case SIOCGSTAMP:
1774                         rc = sock_get_timestamp(sk, argp);
1775                         break;
1776                 case SIOCGSTAMPNS:
1777                         rc = sock_get_timestampns(sk, argp);
1778                         break;
1779                 /* Routing */
1780                 case SIOCADDRT:
1781                 case SIOCDELRT:
1782                         rc = -EPERM;
1783                         if (capable(CAP_NET_ADMIN))
1784                                 rc = atrtr_ioctl(cmd, argp);
1785                         break;
1786                 /* Interface */
1787                 case SIOCGIFADDR:
1788                 case SIOCSIFADDR:
1789                 case SIOCGIFBRDADDR:
1790                 case SIOCATALKDIFADDR:
1791                 case SIOCDIFADDR:
1792                 case SIOCSARP:          /* proxy AARP */
1793                 case SIOCDARP:          /* proxy AARP */
1794                         rtnl_lock();
1795                         rc = atif_ioctl(cmd, argp);
1796                         rtnl_unlock();
1797                         break;
1798         }
1799
1800         return rc;
1801 }
1802
1803
1804 #ifdef CONFIG_COMPAT
1805 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1806 {
1807         /*
1808          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1809          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1810          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1811          * here so there is no generic SIOCPROTOPRIVATE translation in the
1812          * system.
1813          */
1814         return -ENOIOCTLCMD;
1815 }
1816 #endif
1817
1818
1819 static struct net_proto_family atalk_family_ops = {
1820         .family         = PF_APPLETALK,
1821         .create         = atalk_create,
1822         .owner          = THIS_MODULE,
1823 };
1824
1825 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1826         .family         = PF_APPLETALK,
1827         .owner          = THIS_MODULE,
1828         .release        = atalk_release,
1829         .bind           = atalk_bind,
1830         .connect        = atalk_connect,
1831         .socketpair     = sock_no_socketpair,
1832         .accept         = sock_no_accept,
1833         .getname        = atalk_getname,
1834         .poll           = datagram_poll,
1835         .ioctl          = atalk_ioctl,
1836 #ifdef CONFIG_COMPAT
1837         .compat_ioctl   = atalk_compat_ioctl,
1838 #endif
1839         .listen         = sock_no_listen,
1840         .shutdown       = sock_no_shutdown,
1841         .setsockopt     = sock_no_setsockopt,
1842         .getsockopt     = sock_no_getsockopt,
1843         .sendmsg        = atalk_sendmsg,
1844         .recvmsg        = atalk_recvmsg,
1845         .mmap           = sock_no_mmap,
1846         .sendpage       = sock_no_sendpage,
1847 };
1848
1849 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1850
1851 static struct notifier_block ddp_notifier = {
1852         .notifier_call  = ddp_device_event,
1853 };
1854
1855 static struct packet_type ltalk_packet_type __read_mostly = {
1856         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1857         .func           = ltalk_rcv,
1858 };
1859
1860 static struct packet_type ppptalk_packet_type __read_mostly = {
1861         .type           = cpu_to_be16(ETH_P_PPPTALK),
1862         .func           = atalk_rcv,
1863 };
1864
1865 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1866
1867 /* Export symbols for use by drivers when AppleTalk is a module */
1868 EXPORT_SYMBOL(aarp_send_ddp);
1869 EXPORT_SYMBOL(atrtr_get_dev);
1870 EXPORT_SYMBOL(atalk_find_dev_addr);
1871
1872 static const char atalk_err_snap[] __initconst =
1873         KERN_CRIT "Unable to register DDP with SNAP.\n";
1874
1875 /* Called by proto.c on kernel start up */
1876 static int __init atalk_init(void)
1877 {
1878         int rc = proto_register(&ddp_proto, 0);
1879
1880         if (rc != 0)
1881                 goto out;
1882
1883         (void)sock_register(&atalk_family_ops);
1884         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1885         if (!ddp_dl)
1886                 printk(atalk_err_snap);
1887
1888         dev_add_pack(&ltalk_packet_type);
1889         dev_add_pack(&ppptalk_packet_type);
1890
1891         register_netdevice_notifier(&ddp_notifier);
1892         aarp_proto_init();
1893         atalk_proc_init();
1894         atalk_register_sysctl();
1895 out:
1896         return rc;
1897 }
1898 module_init(atalk_init);
1899
1900 /*
1901  * No explicit module reference count manipulation is needed in the
1902  * protocol. Socket layer sets module reference count for us
1903  * and interfaces reference counting is done
1904  * by the network device layer.
1905  *
1906  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1907  * sockets be closed from user space.
1908  */
1909 static void __exit atalk_exit(void)
1910 {
1911 #ifdef CONFIG_SYSCTL
1912         atalk_unregister_sysctl();
1913 #endif /* CONFIG_SYSCTL */
1914         atalk_proc_exit();
1915         aarp_cleanup_module();  /* General aarp clean-up. */
1916         unregister_netdevice_notifier(&ddp_notifier);
1917         dev_remove_pack(&ltalk_packet_type);
1918         dev_remove_pack(&ppptalk_packet_type);
1919         unregister_snap_client(ddp_dl);
1920         sock_unregister(PF_APPLETALK);
1921         proto_unregister(&ddp_proto);
1922 }
1923 module_exit(atalk_exit);
1924
1925 MODULE_LICENSE("GPL");
1926 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1927 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1928 MODULE_ALIAS_NETPROTO(PF_APPLETALK);