linux/net/appletalk/ddp.c
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   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 <linux/compat.h>
  59#include <linux/slab.h>
  60#include <net/datalink.h>
  61#include <net/psnap.h>
  62#include <net/sock.h>
  63#include <net/tcp_states.h>
  64#include <net/route.h>
  65#include <linux/atalk.h>
  66#include <linux/highmem.h>
  67
  68struct datalink_proto *ddp_dl, *aarp_dl;
  69static const struct proto_ops atalk_dgram_ops;
  70
  71/**************************************************************************\
  72*                                                                          *
  73* Handlers for the socket list.                                            *
  74*                                                                          *
  75\**************************************************************************/
  76
  77HLIST_HEAD(atalk_sockets);
  78DEFINE_RWLOCK(atalk_sockets_lock);
  79
  80static inline void __atalk_insert_socket(struct sock *sk)
  81{
  82        sk_add_node(sk, &atalk_sockets);
  83}
  84
  85static inline void atalk_remove_socket(struct sock *sk)
  86{
  87        write_lock_bh(&atalk_sockets_lock);
  88        sk_del_node_init(sk);
  89        write_unlock_bh(&atalk_sockets_lock);
  90}
  91
  92static struct sock *atalk_search_socket(struct sockaddr_at *to,
  93                                        struct atalk_iface *atif)
  94{
  95        struct sock *s;
  96
  97        read_lock_bh(&atalk_sockets_lock);
  98        sk_for_each(s, &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;
 124found:
 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 */
 139static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 140                                                struct sockaddr_at *sat)
 141{
 142        struct sock *s;
 143        struct atalk_sock *at;
 144
 145        write_lock_bh(&atalk_sockets_lock);
 146        sk_for_each(s, &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. */
 156found:
 157        write_unlock_bh(&atalk_sockets_lock);
 158        return s;
 159}
 160
 161static 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
 172static 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 */
 193struct atalk_route *atalk_routes;
 194DEFINE_RWLOCK(atalk_routes_lock);
 195
 196struct atalk_iface *atalk_interfaces;
 197DEFINE_RWLOCK(atalk_interfaces_lock);
 198
 199/* For probing devices or in a routerless network */
 200struct 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 */
 207static 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
 225static 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);
 243out:
 244        return iface;
 245}
 246
 247/* Perform phase 2 AARP probing on our tentative address */
 248static 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 */
 295static 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
 340struct 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
 346static 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;
 372out:
 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 */
 381static 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;
 392out:
 393        return iface;
 394out_err:
 395        iface = NULL;
 396        goto out;
 397}
 398
 399/* Find a match for a specific network:node pair */
 400static 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 */
 429static 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;
 471out:
 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 */
 481struct 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 */
 488static 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 */
 501static 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;
 577out_unlock:
 578        write_unlock_bh(&atalk_routes_lock);
 579out:
 580        return retval;
 581}
 582
 583/* Delete a route. Find it and discard it */
 584static 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;
 603out:
 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 */
 612static 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 */
 633static 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 */
 644static int ddp_device_event(struct notifier_block *this, unsigned long event,
 645                            void *ptr)
 646{
 647        struct net_device *dev = netdev_notifier_info_to_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 */
 661static 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_global(dev, aarp_mcast);
 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 */
 877static 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 */
 919static 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 = rol16(sum, 1);
 926        }
 927        return sum;
 928}
 929
 930/*  Checksum skb data --  similar to skb_checksum  */
 931static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 932                                   int len, unsigned long sum)
 933{
 934        int start = skb_headlen(skb);
 935        struct sk_buff *frag_iter;
 936        int i, copy;
 937
 938        /* checksum stuff in header space */
 939        if ((copy = start - offset) > 0) {
 940                if (copy > len)
 941                        copy = len;
 942                sum = atalk_sum_partial(skb->data + offset, copy, sum);
 943                if ((len -= copy) == 0)
 944                        return sum;
 945
 946                offset += copy;
 947        }
 948
 949        /* checksum stuff in frags */
 950        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 951                int end;
 952                const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 953                WARN_ON(start > offset + len);
 954
 955                end = start + skb_frag_size(frag);
 956                if ((copy = end - offset) > 0) {
 957                        u8 *vaddr;
 958
 959                        if (copy > len)
 960                                copy = len;
 961                        vaddr = kmap_atomic(skb_frag_page(frag));
 962                        sum = atalk_sum_partial(vaddr + frag->page_offset +
 963                                                  offset - start, copy, sum);
 964                        kunmap_atomic(vaddr);
 965
 966                        if (!(len -= copy))
 967                                return sum;
 968                        offset += copy;
 969                }
 970                start = end;
 971        }
 972
 973        skb_walk_frags(skb, frag_iter) {
 974                int end;
 975
 976                WARN_ON(start > offset + len);
 977
 978                end = start + frag_iter->len;
 979                if ((copy = end - offset) > 0) {
 980                        if (copy > len)
 981                                copy = len;
 982                        sum = atalk_sum_skb(frag_iter, offset - start,
 983                                            copy, sum);
 984                        if ((len -= copy) == 0)
 985                                return sum;
 986                        offset += copy;
 987                }
 988                start = end;
 989        }
 990
 991        BUG_ON(len > 0);
 992
 993        return sum;
 994}
 995
 996static __be16 atalk_checksum(const struct sk_buff *skb, int len)
 997{
 998        unsigned long sum;
 999
1000        /* skip header 4 bytes */
1001        sum = atalk_sum_skb(skb, 4, len-4, 0);
1002
1003        /* Use 0xFFFF for 0. 0 itself means none */
1004        return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1005}
1006
1007static struct proto ddp_proto = {
1008        .name     = "DDP",
1009        .owner    = THIS_MODULE,
1010        .obj_size = sizeof(struct atalk_sock),
1011};
1012
1013/*
1014 * Create a socket. Initialise the socket, blank the addresses
1015 * set the state.
1016 */
1017static int atalk_create(struct net *net, struct socket *sock, int protocol,
1018                        int kern)
1019{
1020        struct sock *sk;
1021        int rc = -ESOCKTNOSUPPORT;
1022
1023        if (!net_eq(net, &init_net))
1024                return -EAFNOSUPPORT;
1025
1026        /*
1027         * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1028         * and gives you the full ELAP frame. Should be handy for CAP 8)
1029         */
1030        if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1031                goto out;
1032        rc = -ENOMEM;
1033        sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1034        if (!sk)
1035                goto out;
1036        rc = 0;
1037        sock->ops = &atalk_dgram_ops;
1038        sock_init_data(sock, sk);
1039
1040        /* Checksums on by default */
1041        sock_set_flag(sk, SOCK_ZAPPED);
1042out:
1043        return rc;
1044}
1045
1046/* Free a socket. No work needed */
1047static int atalk_release(struct socket *sock)
1048{
1049        struct sock *sk = sock->sk;
1050
1051        if (sk) {
1052                sock_hold(sk);
1053                lock_sock(sk);
1054
1055                sock_orphan(sk);
1056                sock->sk = NULL;
1057                atalk_destroy_socket(sk);
1058
1059                release_sock(sk);
1060                sock_put(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 */
1075static 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
1086                sk_for_each(s, &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
1101try_next_port:;
1102        }
1103
1104        retval = -EBUSY;
1105out:
1106        write_unlock_bh(&atalk_sockets_lock);
1107        return retval;
1108}
1109
1110static 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);
1126out:
1127        return n;
1128}
1129
1130/* Set the address 'our end' of the connection */
1131static 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        int err;
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        lock_sock(sk);
1146        if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1147                struct atalk_addr *ap = atalk_find_primary();
1148
1149                err = -EADDRNOTAVAIL;
1150                if (!ap)
1151                        goto out;
1152
1153                at->src_net  = addr->sat_addr.s_net = ap->s_net;
1154                at->src_node = addr->sat_addr.s_node = ap->s_node;
1155        } else {
1156                err = -EADDRNOTAVAIL;
1157                if (!atalk_find_interface(addr->sat_addr.s_net,
1158                                          addr->sat_addr.s_node))
1159                        goto out;
1160
1161                at->src_net  = addr->sat_addr.s_net;
1162                at->src_node = addr->sat_addr.s_node;
1163        }
1164
1165        if (addr->sat_port == ATADDR_ANYPORT) {
1166                err = atalk_pick_and_bind_port(sk, addr);
1167
1168                if (err < 0)
1169                        goto out;
1170        } else {
1171                at->src_port = addr->sat_port;
1172
1173                err = -EADDRINUSE;
1174                if (atalk_find_or_insert_socket(sk, addr))
1175                        goto out;
1176        }
1177
1178        sock_reset_flag(sk, SOCK_ZAPPED);
1179        err = 0;
1180out:
1181        release_sock(sk);
1182        return err;
1183}
1184
1185/* Set the address we talk to */
1186static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1187                         int addr_len, int flags)
1188{
1189        struct sock *sk = sock->sk;
1190        struct atalk_sock *at = at_sk(sk);
1191        struct sockaddr_at *addr;
1192        int err;
1193
1194        sk->sk_state   = TCP_CLOSE;
1195        sock->state = SS_UNCONNECTED;
1196
1197        if (addr_len != sizeof(*addr))
1198                return -EINVAL;
1199
1200        addr = (struct sockaddr_at *)uaddr;
1201
1202        if (addr->sat_family != AF_APPLETALK)
1203                return -EAFNOSUPPORT;
1204
1205        if (addr->sat_addr.s_node == ATADDR_BCAST &&
1206            !sock_flag(sk, SOCK_BROADCAST)) {
1207#if 1
1208                pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
1209                        current->comm);
1210#else
1211                return -EACCES;
1212#endif
1213        }
1214
1215        lock_sock(sk);
1216        err = -EBUSY;
1217        if (sock_flag(sk, SOCK_ZAPPED))
1218                if (atalk_autobind(sk) < 0)
1219                        goto out;
1220
1221        err = -ENETUNREACH;
1222        if (!atrtr_get_dev(&addr->sat_addr))
1223                goto out;
1224
1225        at->dest_port = addr->sat_port;
1226        at->dest_net  = addr->sat_addr.s_net;
1227        at->dest_node = addr->sat_addr.s_node;
1228
1229        sock->state  = SS_CONNECTED;
1230        sk->sk_state = TCP_ESTABLISHED;
1231        err = 0;
1232out:
1233        release_sock(sk);
1234        return err;
1235}
1236
1237/*
1238 * Find the name of an AppleTalk socket. Just copy the right
1239 * fields into the sockaddr.
1240 */
1241static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1242                         int *uaddr_len, int peer)
1243{
1244        struct sockaddr_at sat;
1245        struct sock *sk = sock->sk;
1246        struct atalk_sock *at = at_sk(sk);
1247        int err;
1248
1249        lock_sock(sk);
1250        err = -ENOBUFS;
1251        if (sock_flag(sk, SOCK_ZAPPED))
1252                if (atalk_autobind(sk) < 0)
1253                        goto out;
1254
1255        *uaddr_len = sizeof(struct sockaddr_at);
1256        memset(&sat, 0, sizeof(sat));
1257
1258        if (peer) {
1259                err = -ENOTCONN;
1260                if (sk->sk_state != TCP_ESTABLISHED)
1261                        goto out;
1262
1263                sat.sat_addr.s_net  = at->dest_net;
1264                sat.sat_addr.s_node = at->dest_node;
1265                sat.sat_port        = at->dest_port;
1266        } else {
1267                sat.sat_addr.s_net  = at->src_net;
1268                sat.sat_addr.s_node = at->src_node;
1269                sat.sat_port        = at->src_port;
1270        }
1271
1272        err = 0;
1273        sat.sat_family = AF_APPLETALK;
1274        memcpy(uaddr, &sat, sizeof(sat));
1275
1276out:
1277        release_sock(sk);
1278        return err;
1279}
1280
1281#if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1282static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1283{
1284        return skb->data[12] == 22;
1285}
1286
1287static int handle_ip_over_ddp(struct sk_buff *skb)
1288{
1289        struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1290        struct net_device_stats *stats;
1291
1292        /* This needs to be able to handle ipddp"N" devices */
1293        if (!dev) {
1294                kfree_skb(skb);
1295                return NET_RX_DROP;
1296        }
1297
1298        skb->protocol = htons(ETH_P_IP);
1299        skb_pull(skb, 13);
1300        skb->dev   = dev;
1301        skb_reset_transport_header(skb);
1302
1303        stats = netdev_priv(dev);
1304        stats->rx_packets++;
1305        stats->rx_bytes += skb->len + 13;
1306        return netif_rx(skb);  /* Send the SKB up to a higher place. */
1307}
1308#else
1309/* make it easy for gcc to optimize this test out, i.e. kill the code */
1310#define is_ip_over_ddp(skb) 0
1311#define handle_ip_over_ddp(skb) 0
1312#endif
1313
1314static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1315                              struct ddpehdr *ddp, __u16 len_hops, int origlen)
1316{
1317        struct atalk_route *rt;
1318        struct atalk_addr ta;
1319
1320        /*
1321         * Don't route multicast, etc., packets, or packets sent to "this
1322         * network"
1323         */
1324        if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1325                /*
1326                 * FIXME:
1327                 *
1328                 * Can it ever happen that a packet is from a PPP iface and
1329                 * needs to be broadcast onto the default network?
1330                 */
1331                if (dev->type == ARPHRD_PPP)
1332                        printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1333                                          "packet received from PPP iface\n");
1334                goto free_it;
1335        }
1336
1337        ta.s_net  = ddp->deh_dnet;
1338        ta.s_node = ddp->deh_dnode;
1339
1340        /* Route the packet */
1341        rt = atrtr_find(&ta);
1342        /* increment hops count */
1343        len_hops += 1 << 10;
1344        if (!rt || !(len_hops & (15 << 10)))
1345                goto free_it;
1346
1347        /* FIXME: use skb->cb to be able to use shared skbs */
1348
1349        /*
1350         * Route goes through another gateway, so set the target to the
1351         * gateway instead.
1352         */
1353
1354        if (rt->flags & RTF_GATEWAY) {
1355                ta.s_net  = rt->gateway.s_net;
1356                ta.s_node = rt->gateway.s_node;
1357        }
1358
1359        /* Fix up skb->len field */
1360        skb_trim(skb, min_t(unsigned int, origlen,
1361                            (rt->dev->hard_header_len +
1362                             ddp_dl->header_length + (len_hops & 1023))));
1363
1364        /* FIXME: use skb->cb to be able to use shared skbs */
1365        ddp->deh_len_hops = htons(len_hops);
1366
1367        /*
1368         * Send the buffer onwards
1369         *
1370         * Now we must always be careful. If it's come from LocalTalk to
1371         * EtherTalk it might not fit
1372         *
1373         * Order matters here: If a packet has to be copied to make a new
1374         * headroom (rare hopefully) then it won't need unsharing.
1375         *
1376         * Note. ddp-> becomes invalid at the realloc.
1377         */
1378        if (skb_headroom(skb) < 22) {
1379                /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1380                struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1381                kfree_skb(skb);
1382                skb = nskb;
1383        } else
1384                skb = skb_unshare(skb, GFP_ATOMIC);
1385
1386        /*
1387         * If the buffer didn't vanish into the lack of space bitbucket we can
1388         * send it.
1389         */
1390        if (skb == NULL)
1391                goto drop;
1392
1393        if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1394                return NET_RX_DROP;
1395        return NET_RX_SUCCESS;
1396free_it:
1397        kfree_skb(skb);
1398drop:
1399        return NET_RX_DROP;
1400}
1401
1402/**
1403 *      atalk_rcv - Receive a packet (in skb) from device dev
1404 *      @skb - packet received
1405 *      @dev - network device where the packet comes from
1406 *      @pt - packet type
1407 *
1408 *      Receive a packet (in skb) from device dev. This has come from the SNAP
1409 *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1410 *      is the DDP header, skb->len is the DDP length. The physical headers
1411 *      have been extracted. PPP should probably pass frames marked as for this
1412 *      layer.  [ie ARPHRD_ETHERTALK]
1413 */
1414static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1415                     struct packet_type *pt, struct net_device *orig_dev)
1416{
1417        struct ddpehdr *ddp;
1418        struct sock *sock;
1419        struct atalk_iface *atif;
1420        struct sockaddr_at tosat;
1421        int origlen;
1422        __u16 len_hops;
1423
1424        if (!net_eq(dev_net(dev), &init_net))
1425                goto drop;
1426
1427        /* Don't mangle buffer if shared */
1428        if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1429                goto out;
1430
1431        /* Size check and make sure header is contiguous */
1432        if (!pskb_may_pull(skb, sizeof(*ddp)))
1433                goto drop;
1434
1435        ddp = ddp_hdr(skb);
1436
1437        len_hops = ntohs(ddp->deh_len_hops);
1438
1439        /* Trim buffer in case of stray trailing data */
1440        origlen = skb->len;
1441        skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1442
1443        /*
1444         * Size check to see if ddp->deh_len was crap
1445         * (Otherwise we'll detonate most spectacularly
1446         * in the middle of atalk_checksum() or recvmsg()).
1447         */
1448        if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1449                pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1450                         "skb->len=%u)\n", len_hops & 1023, skb->len);
1451                goto drop;
1452        }
1453
1454        /*
1455         * Any checksums. Note we don't do htons() on this == is assumed to be
1456         * valid for net byte orders all over the networking code...
1457         */
1458        if (ddp->deh_sum &&
1459            atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1460                /* Not a valid AppleTalk frame - dustbin time */
1461                goto drop;
1462
1463        /* Check the packet is aimed at us */
1464        if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1465                atif = atalk_find_anynet(ddp->deh_dnode, dev);
1466        else
1467                atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1468
1469        if (!atif) {
1470                /* Not ours, so we route the packet via the correct
1471                 * AppleTalk iface
1472                 */
1473                return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1474        }
1475
1476        /* if IP over DDP is not selected this code will be optimized out */
1477        if (is_ip_over_ddp(skb))
1478                return handle_ip_over_ddp(skb);
1479        /*
1480         * Which socket - atalk_search_socket() looks for a *full match*
1481         * of the <net, node, port> tuple.
1482         */
1483        tosat.sat_addr.s_net  = ddp->deh_dnet;
1484        tosat.sat_addr.s_node = ddp->deh_dnode;
1485        tosat.sat_port        = ddp->deh_dport;
1486
1487        sock = atalk_search_socket(&tosat, atif);
1488        if (!sock) /* But not one of our sockets */
1489                goto drop;
1490
1491        /* Queue packet (standard) */
1492        if (sock_queue_rcv_skb(sock, skb) < 0)
1493                goto drop;
1494
1495        return NET_RX_SUCCESS;
1496
1497drop:
1498        kfree_skb(skb);
1499out:
1500        return NET_RX_DROP;
1501
1502}
1503
1504/*
1505 * Receive a LocalTalk frame. We make some demands on the caller here.
1506 * Caller must provide enough headroom on the packet to pull the short
1507 * header and append a long one.
1508 */
1509static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1510                     struct packet_type *pt, struct net_device *orig_dev)
1511{
1512        if (!net_eq(dev_net(dev), &init_net))
1513                goto freeit;
1514
1515        /* Expand any short form frames */
1516        if (skb_mac_header(skb)[2] == 1) {
1517                struct ddpehdr *ddp;
1518                /* Find our address */
1519                struct atalk_addr *ap = atalk_find_dev_addr(dev);
1520
1521                if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1522                        goto freeit;
1523
1524                /* Don't mangle buffer if shared */
1525                if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1526                        return 0;
1527
1528                /*
1529                 * The push leaves us with a ddephdr not an shdr, and
1530                 * handily the port bytes in the right place preset.
1531                 */
1532                ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1533
1534                /* Now fill in the long header */
1535
1536                /*
1537                 * These two first. The mac overlays the new source/dest
1538                 * network information so we MUST copy these before
1539                 * we write the network numbers !
1540                 */
1541
1542                ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1543                ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1544
1545                ddp->deh_dnet  = ap->s_net;     /* Network number */
1546                ddp->deh_snet  = ap->s_net;
1547                ddp->deh_sum   = 0;             /* No checksum */
1548                /*
1549                 * Not sure about this bit...
1550                 */
1551                /* Non routable, so force a drop if we slip up later */
1552                ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1553        }
1554        skb_reset_transport_header(skb);
1555
1556        return atalk_rcv(skb, dev, pt, orig_dev);
1557freeit:
1558        kfree_skb(skb);
1559        return 0;
1560}
1561
1562static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1563                         size_t len)
1564{
1565        struct sock *sk = sock->sk;
1566        struct atalk_sock *at = at_sk(sk);
1567        DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
1568        int flags = msg->msg_flags;
1569        int loopback = 0;
1570        struct sockaddr_at local_satalk, gsat;
1571        struct sk_buff *skb;
1572        struct net_device *dev;
1573        struct ddpehdr *ddp;
1574        int size;
1575        struct atalk_route *rt;
1576        int err;
1577
1578        if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1579                return -EINVAL;
1580
1581        if (len > DDP_MAXSZ)
1582                return -EMSGSIZE;
1583
1584        lock_sock(sk);
1585        if (usat) {
1586                err = -EBUSY;
1587                if (sock_flag(sk, SOCK_ZAPPED))
1588                        if (atalk_autobind(sk) < 0)
1589                                goto out;
1590
1591                err = -EINVAL;
1592                if (msg->msg_namelen < sizeof(*usat) ||
1593                    usat->sat_family != AF_APPLETALK)
1594                        goto out;
1595
1596                err = -EPERM;
1597                /* netatalk didn't implement this check */
1598                if (usat->sat_addr.s_node == ATADDR_BCAST &&
1599                    !sock_flag(sk, SOCK_BROADCAST)) {
1600                        goto out;
1601                }
1602        } else {
1603                err = -ENOTCONN;
1604                if (sk->sk_state != TCP_ESTABLISHED)
1605                        goto out;
1606                usat = &local_satalk;
1607                usat->sat_family      = AF_APPLETALK;
1608                usat->sat_port        = at->dest_port;
1609                usat->sat_addr.s_node = at->dest_node;
1610                usat->sat_addr.s_net  = at->dest_net;
1611        }
1612
1613        /* Build a packet */
1614        SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1615
1616        /* For headers */
1617        size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1618
1619        if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1620                rt = atrtr_find(&usat->sat_addr);
1621        } else {
1622                struct atalk_addr at_hint;
1623
1624                at_hint.s_node = 0;
1625                at_hint.s_net  = at->src_net;
1626
1627                rt = atrtr_find(&at_hint);
1628        }
1629        err = ENETUNREACH;
1630        if (!rt)
1631                goto out;
1632
1633        dev = rt->dev;
1634
1635        SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1636                        sk, size, dev->name);
1637
1638        size += dev->hard_header_len;
1639        release_sock(sk);
1640        skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1641        lock_sock(sk);
1642        if (!skb)
1643                goto out;
1644
1645        skb_reserve(skb, ddp_dl->header_length);
1646        skb_reserve(skb, dev->hard_header_len);
1647        skb->dev = dev;
1648
1649        SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1650
1651        ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1652        ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1653        ddp->deh_dnet  = usat->sat_addr.s_net;
1654        ddp->deh_snet  = at->src_net;
1655        ddp->deh_dnode = usat->sat_addr.s_node;
1656        ddp->deh_snode = at->src_node;
1657        ddp->deh_dport = usat->sat_port;
1658        ddp->deh_sport = at->src_port;
1659
1660        SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1661
1662        err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1663        if (err) {
1664                kfree_skb(skb);
1665                err = -EFAULT;
1666                goto out;
1667        }
1668
1669        if (sk->sk_no_check_tx)
1670                ddp->deh_sum = 0;
1671        else
1672                ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1673
1674        /*
1675         * Loopback broadcast packets to non gateway targets (ie routes
1676         * to group we are in)
1677         */
1678        if (ddp->deh_dnode == ATADDR_BCAST &&
1679            !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1680                struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1681
1682                if (skb2) {
1683                        loopback = 1;
1684                        SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1685                        /*
1686                         * If it fails it is queued/sent above in the aarp queue
1687                         */
1688                        aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1689                }
1690        }
1691
1692        if (dev->flags & IFF_LOOPBACK || loopback) {
1693                SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1694                /* loop back */
1695                skb_orphan(skb);
1696                if (ddp->deh_dnode == ATADDR_BCAST) {
1697                        struct atalk_addr at_lo;
1698
1699                        at_lo.s_node = 0;
1700                        at_lo.s_net  = 0;
1701
1702                        rt = atrtr_find(&at_lo);
1703                        if (!rt) {
1704                                kfree_skb(skb);
1705                                err = -ENETUNREACH;
1706                                goto out;
1707                        }
1708                        dev = rt->dev;
1709                        skb->dev = dev;
1710                }
1711                ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1712        } else {
1713                SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1714                if (rt->flags & RTF_GATEWAY) {
1715                    gsat.sat_addr = rt->gateway;
1716                    usat = &gsat;
1717                }
1718
1719                /*
1720                 * If it fails it is queued/sent above in the aarp queue
1721                 */
1722                aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1723        }
1724        SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1725
1726out:
1727        release_sock(sk);
1728        return err ? : len;
1729}
1730
1731static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1732                         size_t size, int flags)
1733{
1734        struct sock *sk = sock->sk;
1735        struct ddpehdr *ddp;
1736        int copied = 0;
1737        int offset = 0;
1738        int err = 0;
1739        struct sk_buff *skb;
1740
1741        skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1742                                                flags & MSG_DONTWAIT, &err);
1743        lock_sock(sk);
1744
1745        if (!skb)
1746                goto out;
1747
1748        /* FIXME: use skb->cb to be able to use shared skbs */
1749        ddp = ddp_hdr(skb);
1750        copied = ntohs(ddp->deh_len_hops) & 1023;
1751
1752        if (sk->sk_type != SOCK_RAW) {
1753                offset = sizeof(*ddp);
1754                copied -= offset;
1755        }
1756
1757        if (copied > size) {
1758                copied = size;
1759                msg->msg_flags |= MSG_TRUNC;
1760        }
1761        err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1762
1763        if (!err && msg->msg_name) {
1764                DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
1765                sat->sat_family      = AF_APPLETALK;
1766                sat->sat_port        = ddp->deh_sport;
1767                sat->sat_addr.s_node = ddp->deh_snode;
1768                sat->sat_addr.s_net  = ddp->deh_snet;
1769                msg->msg_namelen     = sizeof(*sat);
1770        }
1771
1772        skb_free_datagram(sk, skb);     /* Free the datagram. */
1773
1774out:
1775        release_sock(sk);
1776        return err ? : copied;
1777}
1778
1779
1780/*
1781 * AppleTalk ioctl calls.
1782 */
1783static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1784{
1785        int rc = -ENOIOCTLCMD;
1786        struct sock *sk = sock->sk;
1787        void __user *argp = (void __user *)arg;
1788
1789        switch (cmd) {
1790        /* Protocol layer */
1791        case TIOCOUTQ: {
1792                long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1793
1794                if (amount < 0)
1795                        amount = 0;
1796                rc = put_user(amount, (int __user *)argp);
1797                break;
1798        }
1799        case TIOCINQ: {
1800                /*
1801                 * These two are safe on a single CPU system as only
1802                 * user tasks fiddle here
1803                 */
1804                struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1805                long amount = 0;
1806
1807                if (skb)
1808                        amount = skb->len - sizeof(struct ddpehdr);
1809                rc = put_user(amount, (int __user *)argp);
1810                break;
1811        }
1812        case SIOCGSTAMP:
1813                rc = sock_get_timestamp(sk, argp);
1814                break;
1815        case SIOCGSTAMPNS:
1816                rc = sock_get_timestampns(sk, argp);
1817                break;
1818        /* Routing */
1819        case SIOCADDRT:
1820        case SIOCDELRT:
1821                rc = -EPERM;
1822                if (capable(CAP_NET_ADMIN))
1823                        rc = atrtr_ioctl(cmd, argp);
1824                break;
1825        /* Interface */
1826        case SIOCGIFADDR:
1827        case SIOCSIFADDR:
1828        case SIOCGIFBRDADDR:
1829        case SIOCATALKDIFADDR:
1830        case SIOCDIFADDR:
1831        case SIOCSARP:          /* proxy AARP */
1832        case SIOCDARP:          /* proxy AARP */
1833                rtnl_lock();
1834                rc = atif_ioctl(cmd, argp);
1835                rtnl_unlock();
1836                break;
1837        }
1838
1839        return rc;
1840}
1841
1842
1843#ifdef CONFIG_COMPAT
1844static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1845{
1846        /*
1847         * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1848         * cannot handle it in common code. The data we access if ifreq
1849         * here is compatible, so we can simply call the native
1850         * handler.
1851         */
1852        if (cmd == SIOCATALKDIFADDR)
1853                return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1854
1855        return -ENOIOCTLCMD;
1856}
1857#endif
1858
1859
1860static const struct net_proto_family atalk_family_ops = {
1861        .family         = PF_APPLETALK,
1862        .create         = atalk_create,
1863        .owner          = THIS_MODULE,
1864};
1865
1866static const struct proto_ops atalk_dgram_ops = {
1867        .family         = PF_APPLETALK,
1868        .owner          = THIS_MODULE,
1869        .release        = atalk_release,
1870        .bind           = atalk_bind,
1871        .connect        = atalk_connect,
1872        .socketpair     = sock_no_socketpair,
1873        .accept         = sock_no_accept,
1874        .getname        = atalk_getname,
1875        .poll           = datagram_poll,
1876        .ioctl          = atalk_ioctl,
1877#ifdef CONFIG_COMPAT
1878        .compat_ioctl   = atalk_compat_ioctl,
1879#endif
1880        .listen         = sock_no_listen,
1881        .shutdown       = sock_no_shutdown,
1882        .setsockopt     = sock_no_setsockopt,
1883        .getsockopt     = sock_no_getsockopt,
1884        .sendmsg        = atalk_sendmsg,
1885        .recvmsg        = atalk_recvmsg,
1886        .mmap           = sock_no_mmap,
1887        .sendpage       = sock_no_sendpage,
1888};
1889
1890static struct notifier_block ddp_notifier = {
1891        .notifier_call  = ddp_device_event,
1892};
1893
1894static struct packet_type ltalk_packet_type __read_mostly = {
1895        .type           = cpu_to_be16(ETH_P_LOCALTALK),
1896        .func           = ltalk_rcv,
1897};
1898
1899static struct packet_type ppptalk_packet_type __read_mostly = {
1900        .type           = cpu_to_be16(ETH_P_PPPTALK),
1901        .func           = atalk_rcv,
1902};
1903
1904static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1905
1906/* Export symbols for use by drivers when AppleTalk is a module */
1907EXPORT_SYMBOL(atrtr_get_dev);
1908EXPORT_SYMBOL(atalk_find_dev_addr);
1909
1910static const char atalk_err_snap[] __initconst =
1911        KERN_CRIT "Unable to register DDP with SNAP.\n";
1912
1913/* Called by proto.c on kernel start up */
1914static int __init atalk_init(void)
1915{
1916        int rc = proto_register(&ddp_proto, 0);
1917
1918        if (rc != 0)
1919                goto out;
1920
1921        (void)sock_register(&atalk_family_ops);
1922        ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1923        if (!ddp_dl)
1924                printk(atalk_err_snap);
1925
1926        dev_add_pack(&ltalk_packet_type);
1927        dev_add_pack(&ppptalk_packet_type);
1928
1929        register_netdevice_notifier(&ddp_notifier);
1930        aarp_proto_init();
1931        atalk_proc_init();
1932        atalk_register_sysctl();
1933out:
1934        return rc;
1935}
1936module_init(atalk_init);
1937
1938/*
1939 * No explicit module reference count manipulation is needed in the
1940 * protocol. Socket layer sets module reference count for us
1941 * and interfaces reference counting is done
1942 * by the network device layer.
1943 *
1944 * Ergo, before the AppleTalk module can be removed, all AppleTalk
1945 * sockets be closed from user space.
1946 */
1947static void __exit atalk_exit(void)
1948{
1949#ifdef CONFIG_SYSCTL
1950        atalk_unregister_sysctl();
1951#endif /* CONFIG_SYSCTL */
1952        atalk_proc_exit();
1953        aarp_cleanup_module();  /* General aarp clean-up. */
1954        unregister_netdevice_notifier(&ddp_notifier);
1955        dev_remove_pack(&ltalk_packet_type);
1956        dev_remove_pack(&ppptalk_packet_type);
1957        unregister_snap_client(ddp_dl);
1958        sock_unregister(PF_APPLETALK);
1959        proto_unregister(&ddp_proto);
1960}
1961module_exit(atalk_exit);
1962
1963MODULE_LICENSE("GPL");
1964MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1965MODULE_DESCRIPTION("AppleTalk 0.20\n");
1966MODULE_ALIAS_NETPROTO(PF_APPLETALK);
1967