git.oblomov.eu Git - linux-2.6/blob - 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/termios.h>      /* For TIOCOUTQ/INQ */
  58 #include <net/datalink.h>
  59 #include <net/psnap.h>
  60 #include <net/sock.h>
  61 #include <net/tcp_states.h>
  62 #include <net/route.h>
  63 #include <linux/atalk.h>
  64 #include "../core/kmap_skb.h"
  65
  66 struct datalink_proto *ddp_dl, *aarp_dl;
  67 static const struct proto_ops atalk_dgram_ops;
  68
  69 /**************************************************************************\
  70 *                                                                          *
  71 * Handlers for the socket list.                                            *
  72 *                                                                          *
  73 \**************************************************************************/
  74
  75 HLIST_HEAD(atalk_sockets);
  76 DEFINE_RWLOCK(atalk_sockets_lock);
  77
  78 static inline void __atalk_insert_socket(struct sock *sk)
  79 {
  80         sk_add_node(sk, &atalk_sockets);
  81 }
  82
  83 static inline void atalk_remove_socket(struct sock *sk)
  84 {
  85         write_lock_bh(&atalk_sockets_lock);
  86         sk_del_node_init(sk);
  87         write_unlock_bh(&atalk_sockets_lock);
  88 }
  89
  90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  91                                         struct atalk_iface *atif)
  92 {
  93         struct sock *s;
  94         struct hlist_node *node;
  95
  96         read_lock_bh(&atalk_sockets_lock);
  97         sk_for_each(s, node, &atalk_sockets) {
  98                 struct atalk_sock *at = at_sk(s);
  99
 100                 if (to->sat_port != at->src_port)
 101                         continue;
 102
 103                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 104                     to->sat_addr.s_node == ATADDR_BCAST)
 105                         goto found;
 106
 107                 if (to->sat_addr.s_net == at->src_net &&
 108                     (to->sat_addr.s_node == at->src_node ||
 109                      to->sat_addr.s_node == ATADDR_BCAST ||
 110                      to->sat_addr.s_node == ATADDR_ANYNODE))
 111                         goto found;
 112
 113                 /* XXXX.0 -- we got a request for this router. make sure
 114                  * that the node is appropriately set. */
 115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 116                     to->sat_addr.s_net != ATADDR_ANYNET &&
 117                     atif->address.s_node == at->src_node) {
 118                         to->sat_addr.s_node = atif->address.s_node;
 119                         goto found;
 120                 }
 121         }
 122         s = NULL;
 123 found:
 124         read_unlock_bh(&atalk_sockets_lock);
 125         return s;
 126 }
 127
 128 /**
 129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 130  * @sk - socket to insert in the list if it is not there already
 131  * @sat - address to search for
 132  *
 133  * Try to find a socket matching ADDR in the socket list, if found then return
 134  * it. If not, insert SK into the socket list.
 135  *
 136  * This entire operation must execute atomically.
 137  */
 138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 139                                                 struct sockaddr_at *sat)
 140 {
 141         struct sock *s;
 142         struct hlist_node *node;
 143         struct atalk_sock *at;
 144
 145         write_lock_bh(&atalk_sockets_lock);
 146         sk_for_each(s, node, &atalk_sockets) {
 147                 at = at_sk(s);
 148
 149                 if (at->src_net == sat->sat_addr.s_net &&
 150                     at->src_node == sat->sat_addr.s_node &&
 151                     at->src_port == sat->sat_port)
 152                         goto found;
 153         }
 154         s = NULL;
 155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 156 found:
 157         write_unlock_bh(&atalk_sockets_lock);
 158         return s;
 159 }
 160
 161 static void atalk_destroy_timer(unsigned long data)
 162 {
 163         struct sock *sk = (struct sock *)data;
 164
 165         if (sk_has_allocations(sk)) {
 166                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 167                 add_timer(&sk->sk_timer);
 168         } else
 169                 sock_put(sk);
 170 }
 171
 172 static inline void atalk_destroy_socket(struct sock *sk)
 173 {
 174         atalk_remove_socket(sk);
 175         skb_queue_purge(&sk->sk_receive_queue);
 176
 177         if (sk_has_allocations(sk)) {
 178                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
 179                                 (unsigned long)sk);
 180                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 181                 add_timer(&sk->sk_timer);
 182         } else
 183                 sock_put(sk);
 184 }
 185
 186 /**************************************************************************\
 187 *                                                                          *
 188 * Routing tables for the AppleTalk socket layer.                           *
 189 *                                                                          *
 190 \**************************************************************************/
 191
 192 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 193 struct atalk_route *atalk_routes;
 194 DEFINE_RWLOCK(atalk_routes_lock);
 195
 196 struct atalk_iface *atalk_interfaces;
 197 DEFINE_RWLOCK(atalk_interfaces_lock);
 198
 199 /* For probing devices or in a routerless network */
 200 struct atalk_route atrtr_default;
 201
 202 /* AppleTalk interface control */
 203 /*
 204  * Drop a device. Doesn't drop any of its routes - that is the caller's
 205  * problem. Called when we down the interface or delete the address.
 206  */
 207 static void atif_drop_device(struct net_device *dev)
 208 {
 209         struct atalk_iface **iface = &atalk_interfaces;
 210         struct atalk_iface *tmp;
 211
 212         write_lock_bh(&atalk_interfaces_lock);
 213         while ((tmp = *iface) != NULL) {
 214                 if (tmp->dev == dev) {
 215                         *iface = tmp->next;
 216                         dev_put(dev);
 217                         kfree(tmp);
 218                         dev->atalk_ptr = NULL;
 219                 } else
 220                         iface = &tmp->next;
 221         }
 222         write_unlock_bh(&atalk_interfaces_lock);
 223 }
 224
 225 static struct atalk_iface *atif_add_device(struct net_device *dev,
 226                                            struct atalk_addr *sa)
 227 {
 228         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 229
 230         if (!iface)
 231                 goto out;
 232
 233         dev_hold(dev);
 234         iface->dev = dev;
 235         dev->atalk_ptr = iface;
 236         iface->address = *sa;
 237         iface->status = 0;
 238
 239         write_lock_bh(&atalk_interfaces_lock);
 240         iface->next = atalk_interfaces;
 241         atalk_interfaces = iface;
 242         write_unlock_bh(&atalk_interfaces_lock);
 243 out:
 244         return iface;
 245 }
 246
 247 /* Perform phase 2 AARP probing on our tentative address */
 248 static int atif_probe_device(struct atalk_iface *atif)
 249 {
 250         int netrange = ntohs(atif->nets.nr_lastnet) -
 251                         ntohs(atif->nets.nr_firstnet) + 1;
 252         int probe_net = ntohs(atif->address.s_net);
 253         int probe_node = atif->address.s_node;
 254         int netct, nodect;
 255
 256         /* Offset the network we start probing with */
 257         if (probe_net == ATADDR_ANYNET) {
 258                 probe_net = ntohs(atif->nets.nr_firstnet);
 259                 if (netrange)
 260                         probe_net += jiffies % netrange;
 261         }
 262         if (probe_node == ATADDR_ANYNODE)
 263                 probe_node = jiffies & 0xFF;
 264
 265         /* Scan the networks */
 266         atif->status |= ATIF_PROBE;
 267         for (netct = 0; netct <= netrange; netct++) {
 268                 /* Sweep the available nodes from a given start */
 269                 atif->address.s_net = htons(probe_net);
 270                 for (nodect = 0; nodect < 256; nodect++) {
 271                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 272                         if (atif->address.s_node > 0 &&
 273                             atif->address.s_node < 254) {
 274                                 /* Probe a proposed address */
 275                                 aarp_probe_network(atif);
 276
 277                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 278                                         atif->status &= ~ATIF_PROBE;
 279                                         return 0;
 280                                 }
 281                         }
 282                         atif->status &= ~ATIF_PROBE_FAIL;
 283                 }
 284                 probe_net++;
 285                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 286                         probe_net = ntohs(atif->nets.nr_firstnet);
 287         }
 288         atif->status &= ~ATIF_PROBE;
 289
 290         return -EADDRINUSE;     /* Network is full... */
 291 }
 292
 293
 294 /* Perform AARP probing for a proxy address */
 295 static int atif_proxy_probe_device(struct atalk_iface *atif,
 296                                    struct atalk_addr* proxy_addr)
 297 {
 298         int netrange = ntohs(atif->nets.nr_lastnet) -
 299                         ntohs(atif->nets.nr_firstnet) + 1;
 300         /* we probe the interface's network */
 301         int probe_net = ntohs(atif->address.s_net);
 302         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 303         int netct, nodect;
 304
 305         /* Offset the network we start probing with */
 306         if (probe_net == ATADDR_ANYNET) {
 307                 probe_net = ntohs(atif->nets.nr_firstnet);
 308                 if (netrange)
 309                         probe_net += jiffies % netrange;
 310         }
 311
 312         if (probe_node == ATADDR_ANYNODE)
 313                 probe_node = jiffies & 0xFF;
 314
 315         /* Scan the networks */
 316         for (netct = 0; netct <= netrange; netct++) {
 317                 /* Sweep the available nodes from a given start */
 318                 proxy_addr->s_net = htons(probe_net);
 319                 for (nodect = 0; nodect < 256; nodect++) {
 320                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 321                         if (proxy_addr->s_node > 0 &&
 322                             proxy_addr->s_node < 254) {
 323                                 /* Tell AARP to probe a proposed address */
 324                                 int ret = aarp_proxy_probe_network(atif,
 325                                                                     proxy_addr);
 326
 327                                 if (ret != -EADDRINUSE)
 328                                         return ret;
 329                         }
 330                 }
 331                 probe_net++;
 332                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 333                         probe_net = ntohs(atif->nets.nr_firstnet);
 334         }
 335
 336         return -EADDRINUSE;     /* Network is full... */
 337 }
 338
 339
 340 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 341 {
 342         struct atalk_iface *iface = dev->atalk_ptr;
 343         return iface ? &iface->address : NULL;
 344 }
 345
 346 static struct atalk_addr *atalk_find_primary(void)
 347 {
 348         struct atalk_iface *fiface = NULL;
 349         struct atalk_addr *retval;
 350         struct atalk_iface *iface;
 351
 352         /*
 353          * Return a point-to-point interface only if
 354          * there is no non-ptp interface available.
 355          */
 356         read_lock_bh(&atalk_interfaces_lock);
 357         for (iface = atalk_interfaces; iface; iface = iface->next) {
 358                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 359                         fiface = iface;
 360                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 361                         retval = &iface->address;
 362                         goto out;
 363                 }
 364         }
 365
 366         if (fiface)
 367                 retval = &fiface->address;
 368         else if (atalk_interfaces)
 369                 retval = &atalk_interfaces->address;
 370         else
 371                 retval = NULL;
 372 out:
 373         read_unlock_bh(&atalk_interfaces_lock);
 374         return retval;
 375 }
 376
 377 /*
 378  * Find a match for 'any network' - ie any of our interfaces with that
 379  * node number will do just nicely.
 380  */
 381 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 382 {
 383         struct atalk_iface *iface = dev->atalk_ptr;
 384
 385         if (!iface || iface->status & ATIF_PROBE)
 386                 goto out_err;
 387
 388         if (node != ATADDR_BCAST &&
 389             iface->address.s_node != node &&
 390             node != ATADDR_ANYNODE)
 391                 goto out_err;
 392 out:
 393         return iface;
 394 out_err:
 395         iface = NULL;
 396         goto out;
 397 }
 398
 399 /* Find a match for a specific network:node pair */
 400 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 401 {
 402         struct atalk_iface *iface;
 403
 404         read_lock_bh(&atalk_interfaces_lock);
 405         for (iface = atalk_interfaces; iface; iface = iface->next) {
 406                 if ((node == ATADDR_BCAST ||
 407                      node == ATADDR_ANYNODE ||
 408                      iface->address.s_node == node) &&
 409                     iface->address.s_net == net &&
 410                     !(iface->status & ATIF_PROBE))
 411                         break;
 412
 413                 /* XXXX.0 -- net.0 returns the iface associated with net */
 414                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 415                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 416                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 417                         break;
 418         }
 419         read_unlock_bh(&atalk_interfaces_lock);
 420         return iface;
 421 }
 422
 423
 424 /*
 425  * Find a route for an AppleTalk packet. This ought to get cached in
 426  * the socket (later on...). We know about host routes and the fact
 427  * that a route must be direct to broadcast.
 428  */
 429 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 430 {
 431         /*
 432          * we must search through all routes unless we find a
 433          * host route, because some host routes might overlap
 434          * network routes
 435          */
 436         struct atalk_route *net_route = NULL;
 437         struct atalk_route *r;
 438
 439         read_lock_bh(&atalk_routes_lock);
 440         for (r = atalk_routes; r; r = r->next) {
 441                 if (!(r->flags & RTF_UP))
 442                         continue;
 443
 444                 if (r->target.s_net == target->s_net) {
 445                         if (r->flags & RTF_HOST) {
 446                                 /*
 447                                  * if this host route is for the target,
 448                                  * the we're done
 449                                  */
 450                                 if (r->target.s_node == target->s_node)
 451                                         goto out;
 452                         } else
 453                                 /*
 454                                  * this route will work if there isn't a
 455                                  * direct host route, so cache it
 456                                  */
 457                                 net_route = r;
 458                 }
 459         }
 460
 461         /*
 462          * if we found a network route but not a direct host
 463          * route, then return it
 464          */
 465         if (net_route)
 466                 r = net_route;
 467         else if (atrtr_default.dev)
 468                 r = &atrtr_default;
 469         else /* No route can be found */
 470                 r = NULL;
 471 out:
 472         read_unlock_bh(&atalk_routes_lock);
 473         return r;
 474 }
 475
 476
 477 /*
 478  * Given an AppleTalk network, find the device to use. This can be
 479  * a simple lookup.
 480  */
 481 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 482 {
 483         struct atalk_route *atr = atrtr_find(sa);
 484         return atr ? atr->dev : NULL;
 485 }
 486
 487 /* Set up a default router */
 488 static void atrtr_set_default(struct net_device *dev)
 489 {
 490         atrtr_default.dev            = dev;
 491         atrtr_default.flags          = RTF_UP;
 492         atrtr_default.gateway.s_net  = htons(0);
 493         atrtr_default.gateway.s_node = 0;
 494 }
 495
 496 /*
 497  * Add a router. Basically make sure it looks valid and stuff the
 498  * entry in the list. While it uses netranges we always set them to one
 499  * entry to work like netatalk.
 500  */
 501 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 502 {
 503         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 504         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 505         struct atalk_route *rt;
 506         struct atalk_iface *iface, *riface;
 507         int retval = -EINVAL;
 508
 509         /*
 510          * Fixme: Raise/Lower a routing change semaphore for these
 511          * operations.
 512          */
 513
 514         /* Validate the request */
 515         if (ta->sat_family != AF_APPLETALK ||
 516             (!devhint && ga->sat_family != AF_APPLETALK))
 517                 goto out;
 518
 519         /* Now walk the routing table and make our decisions */
 520         write_lock_bh(&atalk_routes_lock);
 521         for (rt = atalk_routes; rt; rt = rt->next) {
 522                 if (r->rt_flags != rt->flags)
 523                         continue;
 524
 525                 if (ta->sat_addr.s_net == rt->target.s_net) {
 526                         if (!(rt->flags & RTF_HOST))
 527                                 break;
 528                         if (ta->sat_addr.s_node == rt->target.s_node)
 529                                 break;
 530                 }
 531         }
 532
 533         if (!devhint) {
 534                 riface = NULL;
 535
 536                 read_lock_bh(&atalk_interfaces_lock);
 537                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 538                         if (!riface &&
 539                             ntohs(ga->sat_addr.s_net) >=
 540                                         ntohs(iface->nets.nr_firstnet) &&
 541                             ntohs(ga->sat_addr.s_net) <=
 542                                         ntohs(iface->nets.nr_lastnet))
 543                                 riface = iface;
 544
 545                         if (ga->sat_addr.s_net == iface->address.s_net &&
 546                             ga->sat_addr.s_node == iface->address.s_node)
 547                                 riface = iface;
 548                 }
 549                 read_unlock_bh(&atalk_interfaces_lock);
 550
 551                 retval = -ENETUNREACH;
 552                 if (!riface)
 553                         goto out_unlock;
 554
 555                 devhint = riface->dev;
 556         }
 557
 558         if (!rt) {
 559                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 560
 561                 retval = -ENOBUFS;
 562                 if (!rt)
 563                         goto out_unlock;
 564
 565                 rt->next = atalk_routes;
 566                 atalk_routes = rt;
 567         }
 568
 569         /* Fill in the routing entry */
 570         rt->target  = ta->sat_addr;
 571         dev_hold(devhint);
 572         rt->dev     = devhint;
 573         rt->flags   = r->rt_flags;
 574         rt->gateway = ga->sat_addr;
 575
 576         retval = 0;
 577 out_unlock:
 578         write_unlock_bh(&atalk_routes_lock);
 579 out:
 580         return retval;
 581 }
 582
 583 /* Delete a route. Find it and discard it */
 584 static int atrtr_delete(struct atalk_addr * addr)
 585 {
 586         struct atalk_route **r = &atalk_routes;
 587         int retval = 0;
 588         struct atalk_route *tmp;
 589
 590         write_lock_bh(&atalk_routes_lock);
 591         while ((tmp = *r) != NULL) {
 592                 if (tmp->target.s_net == addr->s_net &&
 593                     (!(tmp->flags&RTF_GATEWAY) ||
 594                      tmp->target.s_node == addr->s_node)) {
 595                         *r = tmp->next;
 596                         dev_put(tmp->dev);
 597                         kfree(tmp);
 598                         goto out;
 599                 }
 600                 r = &tmp->next;
 601         }
 602         retval = -ENOENT;
 603 out:
 604         write_unlock_bh(&atalk_routes_lock);
 605         return retval;
 606 }
 607
 608 /*
 609  * Called when a device is downed. Just throw away any routes
 610  * via it.
 611  */
 612 static void atrtr_device_down(struct net_device *dev)
 613 {
 614         struct atalk_route **r = &atalk_routes;
 615         struct atalk_route *tmp;
 616
 617         write_lock_bh(&atalk_routes_lock);
 618         while ((tmp = *r) != NULL) {
 619                 if (tmp->dev == dev) {
 620                         *r = tmp->next;
 621                         dev_put(dev);
 622                         kfree(tmp);
 623                 } else
 624                         r = &tmp->next;
 625         }
 626         write_unlock_bh(&atalk_routes_lock);
 627
 628         if (atrtr_default.dev == dev)
 629                 atrtr_set_default(NULL);
 630 }
 631
 632 /* Actually down the interface */
 633 static inline void atalk_dev_down(struct net_device *dev)
 634 {
 635         atrtr_device_down(dev); /* Remove all routes for the device */
 636         aarp_device_down(dev);  /* Remove AARP entries for the device */
 637         atif_drop_device(dev);  /* Remove the device */
 638 }
 639
 640 /*
 641  * A device event has occurred. Watch for devices going down and
 642  * delete our use of them (iface and route).
 643  */
 644 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 645                             void *ptr)
 646 {
 647         struct net_device *dev = ptr;
 648
 649         if (!net_eq(dev_net(dev), &init_net))
 650                 return NOTIFY_DONE;
 651
 652         if (event == NETDEV_DOWN)
 653                 /* Discard any use of this */
 654                 atalk_dev_down(dev);
 655
 656         return NOTIFY_DONE;
 657 }
 658
 659 /* ioctl calls. Shouldn't even need touching */
 660 /* Device configuration ioctl calls */
 661 static int atif_ioctl(int cmd, void __user *arg)
 662 {
 663         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 664         struct ifreq atreq;
 665         struct atalk_netrange *nr;
 666         struct sockaddr_at *sa;
 667         struct net_device *dev;
 668         struct atalk_iface *atif;
 669         int ct;
 670         int limit;
 671         struct rtentry rtdef;
 672         int add_route;
 673
 674         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 675                 return -EFAULT;
 676
 677         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
 678         if (!dev)
 679                 return -ENODEV;
 680
 681         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 682         atif = atalk_find_dev(dev);
 683
 684         switch (cmd) {
 685                 case SIOCSIFADDR:
 686                         if (!capable(CAP_NET_ADMIN))
 687                                 return -EPERM;
 688                         if (sa->sat_family != AF_APPLETALK)
 689                                 return -EINVAL;
 690                         if (dev->type != ARPHRD_ETHER &&
 691                             dev->type != ARPHRD_LOOPBACK &&
 692                             dev->type != ARPHRD_LOCALTLK &&
 693                             dev->type != ARPHRD_PPP)
 694                                 return -EPROTONOSUPPORT;
 695
 696                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 697                         add_route = 1;
 698
 699                         /*
 700                          * if this is a point-to-point iface, and we already
 701                          * have an iface for this AppleTalk address, then we
 702                          * should not add a route
 703                          */
 704                         if ((dev->flags & IFF_POINTOPOINT) &&
 705                             atalk_find_interface(sa->sat_addr.s_net,
 706                                                  sa->sat_addr.s_node)) {
 707                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 708                                                   "interface added with "
 709                                                   "existing address\n");
 710                                 add_route = 0;
 711                         }
 712
 713                         /*
 714                          * Phase 1 is fine on LocalTalk but we don't do
 715                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 716                          */
 717                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 718                                 return -EPROTONOSUPPORT;
 719                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 720                             sa->sat_addr.s_node == 254)
 721                                 return -EINVAL;
 722                         if (atif) {
 723                                 /* Already setting address */
 724                                 if (atif->status & ATIF_PROBE)
 725                                         return -EBUSY;
 726
 727                                 atif->address.s_net  = sa->sat_addr.s_net;
 728                                 atif->address.s_node = sa->sat_addr.s_node;
 729                                 atrtr_device_down(dev); /* Flush old routes */
 730                         } else {
 731                                 atif = atif_add_device(dev, &sa->sat_addr);
 732                                 if (!atif)
 733                                         return -ENOMEM;
 734                         }
 735                         atif->nets = *nr;
 736
 737                         /*
 738                          * Check if the chosen address is used. If so we
 739                          * error and atalkd will try another.
 740                          */
 741
 742                         if (!(dev->flags & IFF_LOOPBACK) &&
 743                             !(dev->flags & IFF_POINTOPOINT) &&
 744                             atif_probe_device(atif) < 0) {
 745                                 atif_drop_device(dev);
 746                                 return -EADDRINUSE;
 747                         }
 748
 749                         /* Hey it worked - add the direct routes */
 750                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 751                         sa->sat_family = AF_APPLETALK;
 752                         sa->sat_addr.s_net  = atif->address.s_net;
 753                         sa->sat_addr.s_node = atif->address.s_node;
 754                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 755                         rtdef.rt_flags = RTF_UP;
 756                         sa->sat_family = AF_APPLETALK;
 757                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 758                         if (dev->flags & IFF_LOOPBACK ||
 759                             dev->flags & IFF_POINTOPOINT)
 760                                 rtdef.rt_flags |= RTF_HOST;
 761
 762                         /* Routerless initial state */
 763                         if (nr->nr_firstnet == htons(0) &&
 764                             nr->nr_lastnet == htons(0xFFFE)) {
 765                                 sa->sat_addr.s_net = atif->address.s_net;
 766                                 atrtr_create(&rtdef, dev);
 767                                 atrtr_set_default(dev);
 768                         } else {
 769                                 limit = ntohs(nr->nr_lastnet);
 770                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 771                                         printk(KERN_WARNING "Too many routes/"
 772                                                             "iface.\n");
 773                                         return -EINVAL;
 774                                 }
 775                                 if (add_route)
 776                                         for (ct = ntohs(nr->nr_firstnet);
 777                                              ct <= limit; ct++) {
 778                                                 sa->sat_addr.s_net = htons(ct);
 779                                                 atrtr_create(&rtdef, dev);
 780                                         }
 781                         }
 782                         dev_mc_add(dev, aarp_mcast, 6, 1);
 783                         return 0;
 784
 785                 case SIOCGIFADDR:
 786                         if (!atif)
 787                                 return -EADDRNOTAVAIL;
 788
 789                         sa->sat_family = AF_APPLETALK;
 790                         sa->sat_addr = atif->address;
 791                         break;
 792
 793                 case SIOCGIFBRDADDR:
 794                         if (!atif)
 795                                 return -EADDRNOTAVAIL;
 796
 797                         sa->sat_family = AF_APPLETALK;
 798                         sa->sat_addr.s_net = atif->address.s_net;
 799                         sa->sat_addr.s_node = ATADDR_BCAST;
 800                         break;
 801
 802                 case SIOCATALKDIFADDR:
 803                 case SIOCDIFADDR:
 804                         if (!capable(CAP_NET_ADMIN))
 805                                 return -EPERM;
 806                         if (sa->sat_family != AF_APPLETALK)
 807                                 return -EINVAL;
 808                         atalk_dev_down(dev);
 809                         break;
 810
 811                 case SIOCSARP:
 812                         if (!capable(CAP_NET_ADMIN))
 813                                 return -EPERM;
 814                         if (sa->sat_family != AF_APPLETALK)
 815                                 return -EINVAL;
 816                         /*
 817                          * for now, we only support proxy AARP on ELAP;
 818                          * we should be able to do it for LocalTalk, too.
 819                          */
 820                         if (dev->type != ARPHRD_ETHER)
 821                                 return -EPROTONOSUPPORT;
 822
 823                         /*
 824                          * atif points to the current interface on this network;
 825                          * we aren't concerned about its current status (at
 826                          * least for now), but it has all the settings about
 827                          * the network we're going to probe. Consequently, it
 828                          * must exist.
 829                          */
 830                         if (!atif)
 831                                 return -EADDRNOTAVAIL;
 832
 833                         nr = (struct atalk_netrange *)&(atif->nets);
 834                         /*
 835                          * Phase 1 is fine on Localtalk but we don't do
 836                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 837                          */
 838                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 839                                 return -EPROTONOSUPPORT;
 840
 841                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 842                             sa->sat_addr.s_node == 254)
 843                                 return -EINVAL;
 844
 845                         /*
 846                          * Check if the chosen address is used. If so we
 847                          * error and ATCP will try another.
 848                          */
 849                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 850                                 return -EADDRINUSE;
 851
 852                         /*
 853                          * We now have an address on the local network, and
 854                          * the AARP code will defend it for us until we take it
 855                          * down. We don't set up any routes right now, because
 856                          * ATCP will install them manually via SIOCADDRT.
 857                          */
 858                         break;
 859
 860                 case SIOCDARP:
 861                         if (!capable(CAP_NET_ADMIN))
 862                                 return -EPERM;
 863                         if (sa->sat_family != AF_APPLETALK)
 864                                 return -EINVAL;
 865                         if (!atif)
 866                                 return -EADDRNOTAVAIL;
 867
 868                         /* give to aarp module to remove proxy entry */
 869                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 870                         return 0;
 871         }
 872
 873         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 874 }
 875
 876 /* Routing ioctl() calls */
 877 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 878 {
 879         struct rtentry rt;
 880
 881         if (copy_from_user(&rt, arg, sizeof(rt)))
 882                 return -EFAULT;
 883
 884         switch (cmd) {
 885                 case SIOCDELRT:
 886                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 887                                 return -EINVAL;
 888                         return atrtr_delete(&((struct sockaddr_at *)
 889                                                 &rt.rt_dst)->sat_addr);
 890
 891                 case SIOCADDRT: {
 892                         struct net_device *dev = NULL;
 893                         if (rt.rt_dev) {
 894                                 char name[IFNAMSIZ];
 895                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 896                                         return -EFAULT;
 897                                 name[IFNAMSIZ-1] = '\0';
 898                                 dev = __dev_get_by_name(&init_net, name);
 899                                 if (!dev)
 900                                         return -ENODEV;
 901                         }
 902                         return atrtr_create(&rt, dev);
 903                 }
 904         }
 905         return -EINVAL;
 906 }
 907
 908 /**************************************************************************\
 909 *                                                                          *
 910 * Handling for system calls applied via the various interfaces to an       *
 911 * AppleTalk socket object.                                                 *
 912 *                                                                          *
 913 \**************************************************************************/
 914
 915 /*
 916  * Checksum: This is 'optional'. It's quite likely also a good
 917  * candidate for assembler hackery 8)
 918  */
 919 static unsigned long atalk_sum_partial(const unsigned char *data,
 920                                        int len, unsigned long sum)
 921 {
 922         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 923         while (len--) {
 924                 sum += *data;
 925                 sum <<= 1;
 926                 if (sum & 0x10000) {
 927                         sum++;
 928                         sum &= 0xffff;
 929                 }
 930                 data++;
 931         }
 932         return sum;
 933 }
 934
 935 /*  Checksum skb data --  similar to skb_checksum  */
 936 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 937                                    int len, unsigned long sum)
 938 {
 939         int start = skb_headlen(skb);
 940         struct sk_buff *frag_iter;
 941         int i, copy;
 942
 943         /* checksum stuff in header space */
 944         if ( (copy = start - offset) > 0) {
 945                 if (copy > len)
 946                         copy = len;
 947                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 948                 if ( (len -= copy) == 0)
 949                         return sum;
 950
 951                 offset += copy;
 952         }
 953
 954         /* checksum stuff in frags */
 955         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 956                 int end;
 957
 958                 WARN_ON(start > offset + len);
 959
 960                 end = start + skb_shinfo(skb)->frags[i].size;
 961                 if ((copy = end - offset) > 0) {
 962                         u8 *vaddr;
 963                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 964
 965                         if (copy > len)
 966                                 copy = len;
 967                         vaddr = kmap_skb_frag(frag);
 968                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 969                                                   offset - start, copy, sum);
 970                         kunmap_skb_frag(vaddr);
 971
 972                         if (!(len -= copy))
 973                                 return sum;
 974                         offset += copy;
 975                 }
 976                 start = end;
 977         }
 978
 979         skb_walk_frags(skb, frag_iter) {
 980                 int end;
 981
 982                 WARN_ON(start > offset + len);
 983
 984                 end = start + frag_iter->len;
 985                 if ((copy = end - offset) > 0) {
 986                         if (copy > len)
 987                                 copy = len;
 988                         sum = atalk_sum_skb(frag_iter, offset - start,
 989                                             copy, sum);
 990                         if ((len -= copy) == 0)
 991                                 return sum;
 992                         offset += copy;
 993                 }
 994                 start = end;
 995         }
 996
 997         BUG_ON(len > 0);
 998
 999         return sum;
1000 }
1001
1002 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1003 {
1004         unsigned long sum;
1005
1006         /* skip header 4 bytes */
1007         sum = atalk_sum_skb(skb, 4, len-4, 0);
1008
1009         /* Use 0xFFFF for 0. 0 itself means none */
1010         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1011 }
1012
1013 static struct proto ddp_proto = {
1014         .name     = "DDP",
1015         .owner    = THIS_MODULE,
1016         .obj_size = sizeof(struct atalk_sock),
1017 };
1018
1019 /*
1020  * Create a socket. Initialise the socket, blank the addresses
1021  * set the state.
1022  */
1023 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1024 {
1025         struct sock *sk;
1026         int rc = -ESOCKTNOSUPPORT;
1027
1028         if (net != &init_net)
1029                 return -EAFNOSUPPORT;
1030
1031         /*
1032          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1033          * and gives you the full ELAP frame. Should be handy for CAP 8)
1034          */
1035         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1036                 goto out;
1037         rc = -ENOMEM;
1038         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1039         if (!sk)
1040                 goto out;
1041         rc = 0;
1042         sock->ops = &atalk_dgram_ops;
1043         sock_init_data(sock, sk);
1044
1045         /* Checksums on by default */
1046         sock_set_flag(sk, SOCK_ZAPPED);
1047 out:
1048         return rc;
1049 }
1050
1051 /* Free a socket. No work needed */
1052 static int atalk_release(struct socket *sock)
1053 {
1054         struct sock *sk = sock->sk;
1055
1056         if (sk) {
1057                 sock_orphan(sk);
1058                 sock->sk = NULL;
1059                 atalk_destroy_socket(sk);
1060         }
1061         return 0;
1062 }
1063
1064 /**
1065  * atalk_pick_and_bind_port - Pick a source port when one is not given
1066  * @sk - socket to insert into the tables
1067  * @sat - address to search for
1068  *
1069  * Pick a source port when one is not given. If we can find a suitable free
1070  * one, we insert the socket into the tables using it.
1071  *
1072  * This whole operation must be atomic.
1073  */
1074 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1075 {
1076         int retval;
1077
1078         write_lock_bh(&atalk_sockets_lock);
1079
1080         for (sat->sat_port = ATPORT_RESERVED;
1081              sat->sat_port < ATPORT_LAST;
1082              sat->sat_port++) {
1083                 struct sock *s;
1084                 struct hlist_node *node;
1085
1086                 sk_for_each(s, node, &atalk_sockets) {
1087                         struct atalk_sock *at = at_sk(s);
1088
1089                         if (at->src_net == sat->sat_addr.s_net &&
1090                             at->src_node == sat->sat_addr.s_node &&
1091                             at->src_port == sat->sat_port)
1092                                 goto try_next_port;
1093                 }
1094
1095                 /* Wheee, it's free, assign and insert. */
1096                 __atalk_insert_socket(sk);
1097                 at_sk(sk)->src_port = sat->sat_port;
1098                 retval = 0;
1099                 goto out;
1100
1101 try_next_port:;
1102         }
1103
1104         retval = -EBUSY;
1105 out:
1106         write_unlock_bh(&atalk_sockets_lock);
1107         return retval;
1108 }
1109
1110 static int atalk_autobind(struct sock *sk)
1111 {
1112         struct atalk_sock *at = at_sk(sk);
1113         struct sockaddr_at sat;
1114         struct atalk_addr *ap = atalk_find_primary();
1115         int n = -EADDRNOTAVAIL;
1116
1117         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1118                 goto out;
1119
1120         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1121         at->src_node = sat.sat_addr.s_node = ap->s_node;
1122
1123         n = atalk_pick_and_bind_port(sk, &sat);
1124         if (!n)
1125                 sock_reset_flag(sk, SOCK_ZAPPED);
1126 out:
1127         return n;
1128 }
1129
1130 /* Set the address 'our end' of the connection */
1131 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1132 {
1133         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1134         struct sock *sk = sock->sk;
1135         struct atalk_sock *at = at_sk(sk);
1136
1137         if (!sock_flag(sk, SOCK_ZAPPED) ||
1138             addr_len != sizeof(struct sockaddr_at))
1139                 return -EINVAL;
1140
1141         if (addr->sat_family != AF_APPLETALK)
1142                 return -EAFNOSUPPORT;
1143
1144         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1145                 struct atalk_addr *ap = atalk_find_primary();
1146
1147                 if (!ap)
1148                         return -EADDRNOTAVAIL;
1149
1150                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1151                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1152         } else {
1153                 if (!atalk_find_interface(addr->sat_addr.s_net,
1154                                           addr->sat_addr.s_node))
1155                         return -EADDRNOTAVAIL;
1156
1157                 at->src_net  = addr->sat_addr.s_net;
1158                 at->src_node = addr->sat_addr.s_node;
1159         }
1160
1161         if (addr->sat_port == ATADDR_ANYPORT) {
1162                 int n = atalk_pick_and_bind_port(sk, addr);
1163
1164                 if (n < 0)
1165                         return n;
1166         } else {
1167                 at->src_port = addr->sat_port;
1168
1169                 if (atalk_find_or_insert_socket(sk, addr))
1170                         return -EADDRINUSE;
1171         }
1172
1173         sock_reset_flag(sk, SOCK_ZAPPED);
1174         return 0;
1175 }
1176
1177 /* Set the address we talk to */
1178 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1179                          int addr_len, int flags)
1180 {
1181         struct sock *sk = sock->sk;
1182         struct atalk_sock *at = at_sk(sk);
1183         struct sockaddr_at *addr;
1184
1185         sk->sk_state   = TCP_CLOSE;
1186         sock->state = SS_UNCONNECTED;
1187
1188         if (addr_len != sizeof(*addr))
1189                 return -EINVAL;
1190
1191         addr = (struct sockaddr_at *)uaddr;
1192
1193         if (addr->sat_family != AF_APPLETALK)
1194                 return -EAFNOSUPPORT;
1195
1196         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1197             !sock_flag(sk, SOCK_BROADCAST)) {
1198 #if 1
1199                 printk(KERN_WARNING "%s is broken and did not set "
1200                                     "SO_BROADCAST. It will break when 2.2 is "
1201                                     "released.\n",
1202                         current->comm);
1203 #else
1204                 return -EACCES;
1205 #endif
1206         }
1207
1208         if (sock_flag(sk, SOCK_ZAPPED))
1209                 if (atalk_autobind(sk) < 0)
1210                         return -EBUSY;
1211
1212         if (!atrtr_get_dev(&addr->sat_addr))
1213                 return -ENETUNREACH;
1214
1215         at->dest_port = addr->sat_port;
1216         at->dest_net  = addr->sat_addr.s_net;
1217         at->dest_node = addr->sat_addr.s_node;
1218
1219         sock->state  = SS_CONNECTED;
1220         sk->sk_state = TCP_ESTABLISHED;
1221         return 0;
1222 }
1223
1224 /*
1225  * Find the name of an AppleTalk socket. Just copy the right
1226  * fields into the sockaddr.
1227  */
1228 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1229                          int *uaddr_len, int peer)
1230 {
1231         struct sockaddr_at sat;
1232         struct sock *sk = sock->sk;
1233         struct atalk_sock *at = at_sk(sk);
1234
1235         if (sock_flag(sk, SOCK_ZAPPED))
1236                 if (atalk_autobind(sk) < 0)
1237                         return -ENOBUFS;
1238
1239         *uaddr_len = sizeof(struct sockaddr_at);
1240
1241         if (peer) {
1242                 if (sk->sk_state != TCP_ESTABLISHED)
1243                         return -ENOTCONN;
1244
1245                 sat.sat_addr.s_net  = at->dest_net;
1246                 sat.sat_addr.s_node = at->dest_node;
1247                 sat.sat_port        = at->dest_port;
1248         } else {
1249                 sat.sat_addr.s_net  = at->src_net;
1250                 sat.sat_addr.s_node = at->src_node;
1251                 sat.sat_port        = at->src_port;
1252         }
1253
1254         sat.sat_family = AF_APPLETALK;
1255         memcpy(uaddr, &sat, sizeof(sat));
1256         return 0;
1257 }
1258
1259 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1260 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1261 {
1262         return skb->data[12] == 22;
1263 }
1264
1265 static int handle_ip_over_ddp(struct sk_buff *skb)
1266 {
1267         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1268         struct net_device_stats *stats;
1269
1270         /* This needs to be able to handle ipddp"N" devices */
1271         if (!dev)
1272                 return -ENODEV;
1273
1274         skb->protocol = htons(ETH_P_IP);
1275         skb_pull(skb, 13);
1276         skb->dev   = dev;
1277         skb_reset_transport_header(skb);
1278
1279         stats = netdev_priv(dev);
1280         stats->rx_packets++;
1281         stats->rx_bytes += skb->len + 13;
1282         netif_rx(skb);  /* Send the SKB up to a higher place. */
1283         return 0;
1284 }
1285 #else
1286 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1287 #define is_ip_over_ddp(skb) 0
1288 #define handle_ip_over_ddp(skb) 0
1289 #endif
1290
1291 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1292                                struct ddpehdr *ddp, __u16 len_hops,
1293                                int origlen)
1294 {
1295         struct atalk_route *rt;
1296         struct atalk_addr ta;
1297
1298         /*
1299          * Don't route multicast, etc., packets, or packets sent to "this
1300          * network"
1301          */
1302         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1303                 /*
1304                  * FIXME:
1305                  *
1306                  * Can it ever happen that a packet is from a PPP iface and
1307                  * needs to be broadcast onto the default network?
1308                  */
1309                 if (dev->type == ARPHRD_PPP)
1310                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1311                                           "packet received from PPP iface\n");
1312                 goto free_it;
1313         }
1314
1315         ta.s_net  = ddp->deh_dnet;
1316         ta.s_node = ddp->deh_dnode;
1317
1318         /* Route the packet */
1319         rt = atrtr_find(&ta);
1320         /* increment hops count */
1321         len_hops += 1 << 10;
1322         if (!rt || !(len_hops & (15 << 10)))
1323                 goto free_it;
1324
1325         /* FIXME: use skb->cb to be able to use shared skbs */
1326
1327         /*
1328          * Route goes through another gateway, so set the target to the
1329          * gateway instead.
1330          */
1331
1332         if (rt->flags & RTF_GATEWAY) {
1333                 ta.s_net  = rt->gateway.s_net;
1334                 ta.s_node = rt->gateway.s_node;
1335         }
1336
1337         /* Fix up skb->len field */
1338         skb_trim(skb, min_t(unsigned int, origlen,
1339                             (rt->dev->hard_header_len +
1340                              ddp_dl->header_length + (len_hops & 1023))));
1341
1342         /* FIXME: use skb->cb to be able to use shared skbs */
1343         ddp->deh_len_hops = htons(len_hops);
1344
1345         /*
1346          * Send the buffer onwards
1347          *
1348          * Now we must always be careful. If it's come from LocalTalk to
1349          * EtherTalk it might not fit
1350          *
1351          * Order matters here: If a packet has to be copied to make a new
1352          * headroom (rare hopefully) then it won't need unsharing.
1353          *
1354          * Note. ddp-> becomes invalid at the realloc.
1355          */
1356         if (skb_headroom(skb) < 22) {
1357                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1358                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1359                 kfree_skb(skb);
1360                 if (!nskb)
1361                         goto out;
1362                 skb = nskb;
1363         } else
1364                 skb = skb_unshare(skb, GFP_ATOMIC);
1365
1366         /*
1367          * If the buffer didn't vanish into the lack of space bitbucket we can
1368          * send it.
1369          */
1370         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1371                 goto free_it;
1372 out:
1373         return;
1374 free_it:
1375         kfree_skb(skb);
1376 }
1377
1378 /**
1379  *      atalk_rcv - Receive a packet (in skb) from device dev
1380  *      @skb - packet received
1381  *      @dev - network device where the packet comes from
1382  *      @pt - packet type
1383  *
1384  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1385  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1386  *      is the DDP header, skb->len is the DDP length. The physical headers
1387  *      have been extracted. PPP should probably pass frames marked as for this
1388  *      layer.  [ie ARPHRD_ETHERTALK]
1389  */
1390 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1391                      struct packet_type *pt, struct net_device *orig_dev)
1392 {
1393         struct ddpehdr *ddp;
1394         struct sock *sock;
1395         struct atalk_iface *atif;
1396         struct sockaddr_at tosat;
1397         int origlen;
1398         __u16 len_hops;
1399
1400         if (!net_eq(dev_net(dev), &init_net))
1401                 goto freeit;
1402
1403         /* Don't mangle buffer if shared */
1404         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1405                 goto out;
1406
1407         /* Size check and make sure header is contiguous */
1408         if (!pskb_may_pull(skb, sizeof(*ddp)))
1409                 goto freeit;
1410
1411         ddp = ddp_hdr(skb);
1412
1413         len_hops = ntohs(ddp->deh_len_hops);
1414
1415         /* Trim buffer in case of stray trailing data */
1416         origlen = skb->len;
1417         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1418
1419         /*
1420          * Size check to see if ddp->deh_len was crap
1421          * (Otherwise we'll detonate most spectacularly
1422          * in the middle of atalk_checksum() or recvmsg()).
1423          */
1424         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1425                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1426                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1427                 goto freeit;
1428         }
1429
1430         /*
1431          * Any checksums. Note we don't do htons() on this == is assumed to be
1432          * valid for net byte orders all over the networking code...
1433          */
1434         if (ddp->deh_sum &&
1435             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1436                 /* Not a valid AppleTalk frame - dustbin time */
1437                 goto freeit;
1438
1439         /* Check the packet is aimed at us */
1440         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1441                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1442         else
1443                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1444
1445         if (!atif) {
1446                 /* Not ours, so we route the packet via the correct
1447                  * AppleTalk iface
1448                  */
1449                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1450                 goto out;
1451         }
1452
1453         /* if IP over DDP is not selected this code will be optimized out */
1454         if (is_ip_over_ddp(skb))
1455                 return handle_ip_over_ddp(skb);
1456         /*
1457          * Which socket - atalk_search_socket() looks for a *full match*
1458          * of the <net, node, port> tuple.
1459          */
1460         tosat.sat_addr.s_net  = ddp->deh_dnet;
1461         tosat.sat_addr.s_node = ddp->deh_dnode;
1462         tosat.sat_port        = ddp->deh_dport;
1463
1464         sock = atalk_search_socket(&tosat, atif);
1465         if (!sock) /* But not one of our sockets */
1466                 goto freeit;
1467
1468         /* Queue packet (standard) */
1469         skb->sk = sock;
1470
1471         if (sock_queue_rcv_skb(sock, skb) < 0)
1472                 goto freeit;
1473 out:
1474         return 0;
1475 freeit:
1476         kfree_skb(skb);
1477         goto out;
1478 }
1479
1480 /*
1481  * Receive a LocalTalk frame. We make some demands on the caller here.
1482  * Caller must provide enough headroom on the packet to pull the short
1483  * header and append a long one.
1484  */
1485 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1486                      struct packet_type *pt, struct net_device *orig_dev)
1487 {
1488         if (!net_eq(dev_net(dev), &init_net))
1489                 goto freeit;
1490
1491         /* Expand any short form frames */
1492         if (skb_mac_header(skb)[2] == 1) {
1493                 struct ddpehdr *ddp;
1494                 /* Find our address */
1495                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1496
1497                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1498                         goto freeit;
1499
1500                 /* Don't mangle buffer if shared */
1501                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1502                         return 0;
1503
1504                 /*
1505                  * The push leaves us with a ddephdr not an shdr, and
1506                  * handily the port bytes in the right place preset.
1507                  */
1508                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1509
1510                 /* Now fill in the long header */
1511
1512                 /*
1513                  * These two first. The mac overlays the new source/dest
1514                  * network information so we MUST copy these before
1515                  * we write the network numbers !
1516                  */
1517
1518                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1519                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1520
1521                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1522                 ddp->deh_snet  = ap->s_net;
1523                 ddp->deh_sum   = 0;             /* No checksum */
1524                 /*
1525                  * Not sure about this bit...
1526                  */
1527                 /* Non routable, so force a drop if we slip up later */
1528                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1529         }
1530         skb_reset_transport_header(skb);
1531
1532         return atalk_rcv(skb, dev, pt, orig_dev);
1533 freeit:
1534         kfree_skb(skb);
1535         return 0;
1536 }
1537
1538 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1539                          size_t len)
1540 {
1541         struct sock *sk = sock->sk;
1542         struct atalk_sock *at = at_sk(sk);
1543         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1544         int flags = msg->msg_flags;
1545         int loopback = 0;
1546         struct sockaddr_at local_satalk, gsat;
1547         struct sk_buff *skb;
1548         struct net_device *dev;
1549         struct ddpehdr *ddp;
1550         int size;
1551         struct atalk_route *rt;
1552         int err;
1553
1554         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1555                 return -EINVAL;
1556
1557         if (len > DDP_MAXSZ)
1558                 return -EMSGSIZE;
1559
1560         if (usat) {
1561                 if (sock_flag(sk, SOCK_ZAPPED))
1562                         if (atalk_autobind(sk) < 0)
1563                                 return -EBUSY;
1564
1565                 if (msg->msg_namelen < sizeof(*usat) ||
1566                     usat->sat_family != AF_APPLETALK)
1567                         return -EINVAL;
1568
1569                 /* netatalk didn't implement this check */
1570                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1571                     !sock_flag(sk, SOCK_BROADCAST)) {
1572                         return -EPERM;
1573                 }
1574         } else {
1575                 if (sk->sk_state != TCP_ESTABLISHED)
1576                         return -ENOTCONN;
1577                 usat = &local_satalk;
1578                 usat->sat_family      = AF_APPLETALK;
1579                 usat->sat_port        = at->dest_port;
1580                 usat->sat_addr.s_node = at->dest_node;
1581                 usat->sat_addr.s_net  = at->dest_net;
1582         }
1583
1584         /* Build a packet */
1585         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1586
1587         /* For headers */
1588         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1589
1590         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1591                 rt = atrtr_find(&usat->sat_addr);
1592         } else {
1593                 struct atalk_addr at_hint;
1594
1595                 at_hint.s_node = 0;
1596                 at_hint.s_net  = at->src_net;
1597
1598                 rt = atrtr_find(&at_hint);
1599         }
1600         if (!rt)
1601                 return -ENETUNREACH;
1602
1603         dev = rt->dev;
1604
1605         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1606                         sk, size, dev->name);
1607
1608         size += dev->hard_header_len;
1609         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1610         if (!skb)
1611                 return err;
1612
1613         skb->sk = sk;
1614         skb_reserve(skb, ddp_dl->header_length);
1615         skb_reserve(skb, dev->hard_header_len);
1616         skb->dev = dev;
1617
1618         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1619
1620         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1621         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1622         ddp->deh_dnet  = usat->sat_addr.s_net;
1623         ddp->deh_snet  = at->src_net;
1624         ddp->deh_dnode = usat->sat_addr.s_node;
1625         ddp->deh_snode = at->src_node;
1626         ddp->deh_dport = usat->sat_port;
1627         ddp->deh_sport = at->src_port;
1628
1629         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1630
1631         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1632         if (err) {
1633                 kfree_skb(skb);
1634                 return -EFAULT;
1635         }
1636
1637         if (sk->sk_no_check == 1)
1638                 ddp->deh_sum = 0;
1639         else
1640                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1641
1642         /*
1643          * Loopback broadcast packets to non gateway targets (ie routes
1644          * to group we are in)
1645          */
1646         if (ddp->deh_dnode == ATADDR_BCAST &&
1647             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1648                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1649
1650                 if (skb2) {
1651                         loopback = 1;
1652                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1653                         if (aarp_send_ddp(dev, skb2,
1654                                           &usat->sat_addr, NULL) == -1)
1655                                 kfree_skb(skb2);
1656                                 /* else queued/sent above in the aarp queue */
1657                 }
1658         }
1659
1660         if (dev->flags & IFF_LOOPBACK || loopback) {
1661                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1662                 /* loop back */
1663                 skb_orphan(skb);
1664                 if (ddp->deh_dnode == ATADDR_BCAST) {
1665                         struct atalk_addr at_lo;
1666
1667                         at_lo.s_node = 0;
1668                         at_lo.s_net  = 0;
1669
1670                         rt = atrtr_find(&at_lo);
1671                         if (!rt) {
1672                                 kfree_skb(skb);
1673                                 return -ENETUNREACH;
1674                         }
1675                         dev = rt->dev;
1676                         skb->dev = dev;
1677                 }
1678                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1679         } else {
1680                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1681                 if (rt->flags & RTF_GATEWAY) {
1682                     gsat.sat_addr = rt->gateway;
1683                     usat = &gsat;
1684                 }
1685
1686                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1687                         kfree_skb(skb);
1688                 /* else queued/sent above in the aarp queue */
1689         }
1690         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1691
1692         return len;
1693 }
1694
1695 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1696                          size_t size, int flags)
1697 {
1698         struct sock *sk = sock->sk;
1699         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1700         struct ddpehdr *ddp;
1701         int copied = 0;
1702         int offset = 0;
1703         int err = 0;
1704         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1705                                                 flags & MSG_DONTWAIT, &err);
1706         if (!skb)
1707                 return err;
1708
1709         /* FIXME: use skb->cb to be able to use shared skbs */
1710         ddp = ddp_hdr(skb);
1711         copied = ntohs(ddp->deh_len_hops) & 1023;
1712
1713         if (sk->sk_type != SOCK_RAW) {
1714                 offset = sizeof(*ddp);
1715                 copied -= offset;
1716         }
1717
1718         if (copied > size) {
1719                 copied = size;
1720                 msg->msg_flags |= MSG_TRUNC;
1721         }
1722         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1723
1724         if (!err) {
1725                 if (sat) {
1726                         sat->sat_family      = AF_APPLETALK;
1727                         sat->sat_port        = ddp->deh_sport;
1728                         sat->sat_addr.s_node = ddp->deh_snode;
1729                         sat->sat_addr.s_net  = ddp->deh_snet;
1730                 }
1731                 msg->msg_namelen = sizeof(*sat);
1732         }
1733
1734         skb_free_datagram(sk, skb);     /* Free the datagram. */
1735         return err ? : copied;
1736 }
1737
1738
1739 /*
1740  * AppleTalk ioctl calls.
1741  */
1742 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1743 {
1744         int rc = -ENOIOCTLCMD;
1745         struct sock *sk = sock->sk;
1746         void __user *argp = (void __user *)arg;
1747
1748         switch (cmd) {
1749                 /* Protocol layer */
1750                 case TIOCOUTQ: {
1751                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1752
1753                         if (amount < 0)
1754                                 amount = 0;
1755                         rc = put_user(amount, (int __user *)argp);
1756                         break;
1757                 }
1758                 case TIOCINQ: {
1759                         /*
1760                          * These two are safe on a single CPU system as only
1761                          * user tasks fiddle here
1762                          */
1763                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1764                         long amount = 0;
1765
1766                         if (skb)
1767                                 amount = skb->len - sizeof(struct ddpehdr);
1768                         rc = put_user(amount, (int __user *)argp);
1769                         break;
1770                 }
1771                 case SIOCGSTAMP:
1772                         rc = sock_get_timestamp(sk, argp);
1773                         break;
1774                 case SIOCGSTAMPNS:
1775                         rc = sock_get_timestampns(sk, argp);
1776                         break;
1777                 /* Routing */
1778                 case SIOCADDRT:
1779                 case SIOCDELRT:
1780                         rc = -EPERM;
1781                         if (capable(CAP_NET_ADMIN))
1782                                 rc = atrtr_ioctl(cmd, argp);
1783                         break;
1784                 /* Interface */
1785                 case SIOCGIFADDR:
1786                 case SIOCSIFADDR:
1787                 case SIOCGIFBRDADDR:
1788                 case SIOCATALKDIFADDR:
1789                 case SIOCDIFADDR:
1790                 case SIOCSARP:          /* proxy AARP */
1791                 case SIOCDARP:          /* proxy AARP */
1792                         rtnl_lock();
1793                         rc = atif_ioctl(cmd, argp);
1794                         rtnl_unlock();
1795                         break;
1796         }
1797
1798         return rc;
1799 }
1800
1801
1802 #ifdef CONFIG_COMPAT
1803 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1804 {
1805         /*
1806          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1807          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1808          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1809          * here so there is no generic SIOCPROTOPRIVATE translation in the
1810          * system.
1811          */
1812         return -ENOIOCTLCMD;
1813 }
1814 #endif
1815
1816
1817 static struct net_proto_family atalk_family_ops = {
1818         .family         = PF_APPLETALK,
1819         .create         = atalk_create,
1820         .owner          = THIS_MODULE,
1821 };
1822
1823 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1824         .family         = PF_APPLETALK,
1825         .owner          = THIS_MODULE,
1826         .release        = atalk_release,
1827         .bind           = atalk_bind,
1828         .connect        = atalk_connect,
1829         .socketpair     = sock_no_socketpair,
1830         .accept         = sock_no_accept,
1831         .getname        = atalk_getname,
1832         .poll           = datagram_poll,
1833         .ioctl          = atalk_ioctl,
1834 #ifdef CONFIG_COMPAT
1835         .compat_ioctl   = atalk_compat_ioctl,
1836 #endif
1837         .listen         = sock_no_listen,
1838         .shutdown       = sock_no_shutdown,
1839         .setsockopt     = sock_no_setsockopt,
1840         .getsockopt     = sock_no_getsockopt,
1841         .sendmsg        = atalk_sendmsg,
1842         .recvmsg        = atalk_recvmsg,
1843         .mmap           = sock_no_mmap,
1844         .sendpage       = sock_no_sendpage,
1845 };
1846
1847 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1848
1849 static struct notifier_block ddp_notifier = {
1850         .notifier_call  = ddp_device_event,
1851 };
1852
1853 static struct packet_type ltalk_packet_type __read_mostly = {
1854         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1855         .func           = ltalk_rcv,
1856 };
1857
1858 static struct packet_type ppptalk_packet_type __read_mostly = {
1859         .type           = cpu_to_be16(ETH_P_PPPTALK),
1860         .func           = atalk_rcv,
1861 };
1862
1863 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1864
1865 /* Export symbols for use by drivers when AppleTalk is a module */
1866 EXPORT_SYMBOL(aarp_send_ddp);
1867 EXPORT_SYMBOL(atrtr_get_dev);
1868 EXPORT_SYMBOL(atalk_find_dev_addr);
1869
1870 static const char atalk_err_snap[] __initconst =
1871         KERN_CRIT "Unable to register DDP with SNAP.\n";
1872
1873 /* Called by proto.c on kernel start up */
1874 static int __init atalk_init(void)
1875 {
1876         int rc = proto_register(&ddp_proto, 0);
1877
1878         if (rc != 0)
1879                 goto out;
1880
1881         (void)sock_register(&atalk_family_ops);
1882         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1883         if (!ddp_dl)
1884                 printk(atalk_err_snap);
1885
1886         dev_add_pack(&ltalk_packet_type);
1887         dev_add_pack(&ppptalk_packet_type);
1888
1889         register_netdevice_notifier(&ddp_notifier);
1890         aarp_proto_init();
1891         atalk_proc_init();
1892         atalk_register_sysctl();
1893 out:
1894         return rc;
1895 }
1896 module_init(atalk_init);
1897
1898 /*
1899  * No explicit module reference count manipulation is needed in the
1900  * protocol. Socket layer sets module reference count for us
1901  * and interfaces reference counting is done
1902  * by the network device layer.
1903  *
1904  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1905  * sockets be closed from user space.
1906  */
1907 static void __exit atalk_exit(void)
1908 {
1909 #ifdef CONFIG_SYSCTL
1910         atalk_unregister_sysctl();
1911 #endif /* CONFIG_SYSCTL */
1912         atalk_proc_exit();
1913         aarp_cleanup_module();  /* General aarp clean-up. */
1914         unregister_netdevice_notifier(&ddp_notifier);
1915         dev_remove_pack(&ltalk_packet_type);
1916         dev_remove_pack(&ppptalk_packet_type);
1917         unregister_snap_client(ddp_dl);
1918         sock_unregister(PF_APPLETALK);
1919         proto_unregister(&ddp_proto);
1920 }
1921 module_exit(atalk_exit);
1922
1923 MODULE_LICENSE("GPL");
1924 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1925 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1926 MODULE_ALIAS_NETPROTO(PF_APPLETALK);