[NET]: Make packet reception network namespace safe
[linux-2.6] / net / appletalk / ddp.c
1 /*
2  *      DDP:    An implementation of the AppleTalk DDP protocol for
3  *              Ethernet 'ELAP'.
4  *
5  *              Alan Cox  <Alan.Cox@linux.org>
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 (atomic_read(&sk->sk_wmem_alloc) ||
166             atomic_read(&sk->sk_rmem_alloc)) {
167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
168                 add_timer(&sk->sk_timer);
169         } else
170                 sock_put(sk);
171 }
172
173 static inline void atalk_destroy_socket(struct sock *sk)
174 {
175         atalk_remove_socket(sk);
176         skb_queue_purge(&sk->sk_receive_queue);
177
178         if (atomic_read(&sk->sk_wmem_alloc) ||
179             atomic_read(&sk->sk_rmem_alloc)) {
180                 init_timer(&sk->sk_timer);
181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
182                 sk->sk_timer.function   = atalk_destroy_timer;
183                 sk->sk_timer.data       = (unsigned long)sk;
184                 add_timer(&sk->sk_timer);
185         } else
186                 sock_put(sk);
187 }
188
189 /**************************************************************************\
190 *                                                                          *
191 * Routing tables for the AppleTalk socket layer.                           *
192 *                                                                          *
193 \**************************************************************************/
194
195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
196 struct atalk_route *atalk_routes;
197 DEFINE_RWLOCK(atalk_routes_lock);
198
199 struct atalk_iface *atalk_interfaces;
200 DEFINE_RWLOCK(atalk_interfaces_lock);
201
202 /* For probing devices or in a routerless network */
203 struct atalk_route atrtr_default;
204
205 /* AppleTalk interface control */
206 /*
207  * Drop a device. Doesn't drop any of its routes - that is the caller's
208  * problem. Called when we down the interface or delete the address.
209  */
210 static void atif_drop_device(struct net_device *dev)
211 {
212         struct atalk_iface **iface = &atalk_interfaces;
213         struct atalk_iface *tmp;
214
215         write_lock_bh(&atalk_interfaces_lock);
216         while ((tmp = *iface) != NULL) {
217                 if (tmp->dev == dev) {
218                         *iface = tmp->next;
219                         dev_put(dev);
220                         kfree(tmp);
221                         dev->atalk_ptr = NULL;
222                 } else
223                         iface = &tmp->next;
224         }
225         write_unlock_bh(&atalk_interfaces_lock);
226 }
227
228 static struct atalk_iface *atif_add_device(struct net_device *dev,
229                                            struct atalk_addr *sa)
230 {
231         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
232
233         if (!iface)
234                 goto out;
235
236         dev_hold(dev);
237         iface->dev = dev;
238         dev->atalk_ptr = iface;
239         iface->address = *sa;
240         iface->status = 0;
241
242         write_lock_bh(&atalk_interfaces_lock);
243         iface->next = atalk_interfaces;
244         atalk_interfaces = iface;
245         write_unlock_bh(&atalk_interfaces_lock);
246 out:
247         return iface;
248 }
249
250 /* Perform phase 2 AARP probing on our tentative address */
251 static int atif_probe_device(struct atalk_iface *atif)
252 {
253         int netrange = ntohs(atif->nets.nr_lastnet) -
254                         ntohs(atif->nets.nr_firstnet) + 1;
255         int probe_net = ntohs(atif->address.s_net);
256         int probe_node = atif->address.s_node;
257         int netct, nodect;
258
259         /* Offset the network we start probing with */
260         if (probe_net == ATADDR_ANYNET) {
261                 probe_net = ntohs(atif->nets.nr_firstnet);
262                 if (netrange)
263                         probe_net += jiffies % netrange;
264         }
265         if (probe_node == ATADDR_ANYNODE)
266                 probe_node = jiffies & 0xFF;
267
268         /* Scan the networks */
269         atif->status |= ATIF_PROBE;
270         for (netct = 0; netct <= netrange; netct++) {
271                 /* Sweep the available nodes from a given start */
272                 atif->address.s_net = htons(probe_net);
273                 for (nodect = 0; nodect < 256; nodect++) {
274                         atif->address.s_node = (nodect + probe_node) & 0xFF;
275                         if (atif->address.s_node > 0 &&
276                             atif->address.s_node < 254) {
277                                 /* Probe a proposed address */
278                                 aarp_probe_network(atif);
279
280                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
281                                         atif->status &= ~ATIF_PROBE;
282                                         return 0;
283                                 }
284                         }
285                         atif->status &= ~ATIF_PROBE_FAIL;
286                 }
287                 probe_net++;
288                 if (probe_net > ntohs(atif->nets.nr_lastnet))
289                         probe_net = ntohs(atif->nets.nr_firstnet);
290         }
291         atif->status &= ~ATIF_PROBE;
292
293         return -EADDRINUSE;     /* Network is full... */
294 }
295
296
297 /* Perform AARP probing for a proxy address */
298 static int atif_proxy_probe_device(struct atalk_iface *atif,
299                                    struct atalk_addr* proxy_addr)
300 {
301         int netrange = ntohs(atif->nets.nr_lastnet) -
302                         ntohs(atif->nets.nr_firstnet) + 1;
303         /* we probe the interface's network */
304         int probe_net = ntohs(atif->address.s_net);
305         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
306         int netct, nodect;
307
308         /* Offset the network we start probing with */
309         if (probe_net == ATADDR_ANYNET) {
310                 probe_net = ntohs(atif->nets.nr_firstnet);
311                 if (netrange)
312                         probe_net += jiffies % netrange;
313         }
314
315         if (probe_node == ATADDR_ANYNODE)
316                 probe_node = jiffies & 0xFF;
317
318         /* Scan the networks */
319         for (netct = 0; netct <= netrange; netct++) {
320                 /* Sweep the available nodes from a given start */
321                 proxy_addr->s_net = htons(probe_net);
322                 for (nodect = 0; nodect < 256; nodect++) {
323                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
324                         if (proxy_addr->s_node > 0 &&
325                             proxy_addr->s_node < 254) {
326                                 /* Tell AARP to probe a proposed address */
327                                 int ret = aarp_proxy_probe_network(atif,
328                                                                     proxy_addr);
329
330                                 if (ret != -EADDRINUSE)
331                                         return ret;
332                         }
333                 }
334                 probe_net++;
335                 if (probe_net > ntohs(atif->nets.nr_lastnet))
336                         probe_net = ntohs(atif->nets.nr_firstnet);
337         }
338
339         return -EADDRINUSE;     /* Network is full... */
340 }
341
342
343 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
344 {
345         struct atalk_iface *iface = dev->atalk_ptr;
346         return iface ? &iface->address : NULL;
347 }
348
349 static struct atalk_addr *atalk_find_primary(void)
350 {
351         struct atalk_iface *fiface = NULL;
352         struct atalk_addr *retval;
353         struct atalk_iface *iface;
354
355         /*
356          * Return a point-to-point interface only if
357          * there is no non-ptp interface available.
358          */
359         read_lock_bh(&atalk_interfaces_lock);
360         for (iface = atalk_interfaces; iface; iface = iface->next) {
361                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
362                         fiface = iface;
363                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
364                         retval = &iface->address;
365                         goto out;
366                 }
367         }
368
369         if (fiface)
370                 retval = &fiface->address;
371         else if (atalk_interfaces)
372                 retval = &atalk_interfaces->address;
373         else
374                 retval = NULL;
375 out:
376         read_unlock_bh(&atalk_interfaces_lock);
377         return retval;
378 }
379
380 /*
381  * Find a match for 'any network' - ie any of our interfaces with that
382  * node number will do just nicely.
383  */
384 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
385 {
386         struct atalk_iface *iface = dev->atalk_ptr;
387
388         if (!iface || iface->status & ATIF_PROBE)
389                 goto out_err;
390
391         if (node != ATADDR_BCAST &&
392             iface->address.s_node != node &&
393             node != ATADDR_ANYNODE)
394                 goto out_err;
395 out:
396         return iface;
397 out_err:
398         iface = NULL;
399         goto out;
400 }
401
402 /* Find a match for a specific network:node pair */
403 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
404 {
405         struct atalk_iface *iface;
406
407         read_lock_bh(&atalk_interfaces_lock);
408         for (iface = atalk_interfaces; iface; iface = iface->next) {
409                 if ((node == ATADDR_BCAST ||
410                      node == ATADDR_ANYNODE ||
411                      iface->address.s_node == node) &&
412                     iface->address.s_net == net &&
413                     !(iface->status & ATIF_PROBE))
414                         break;
415
416                 /* XXXX.0 -- net.0 returns the iface associated with net */
417                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
418                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
419                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
420                         break;
421         }
422         read_unlock_bh(&atalk_interfaces_lock);
423         return iface;
424 }
425
426
427 /*
428  * Find a route for an AppleTalk packet. This ought to get cached in
429  * the socket (later on...). We know about host routes and the fact
430  * that a route must be direct to broadcast.
431  */
432 static struct atalk_route *atrtr_find(struct atalk_addr *target)
433 {
434         /*
435          * we must search through all routes unless we find a
436          * host route, because some host routes might overlap
437          * network routes
438          */
439         struct atalk_route *net_route = NULL;
440         struct atalk_route *r;
441
442         read_lock_bh(&atalk_routes_lock);
443         for (r = atalk_routes; r; r = r->next) {
444                 if (!(r->flags & RTF_UP))
445                         continue;
446
447                 if (r->target.s_net == target->s_net) {
448                         if (r->flags & RTF_HOST) {
449                                 /*
450                                  * if this host route is for the target,
451                                  * the we're done
452                                  */
453                                 if (r->target.s_node == target->s_node)
454                                         goto out;
455                         } else
456                                 /*
457                                  * this route will work if there isn't a
458                                  * direct host route, so cache it
459                                  */
460                                 net_route = r;
461                 }
462         }
463
464         /*
465          * if we found a network route but not a direct host
466          * route, then return it
467          */
468         if (net_route)
469                 r = net_route;
470         else if (atrtr_default.dev)
471                 r = &atrtr_default;
472         else /* No route can be found */
473                 r = NULL;
474 out:
475         read_unlock_bh(&atalk_routes_lock);
476         return r;
477 }
478
479
480 /*
481  * Given an AppleTalk network, find the device to use. This can be
482  * a simple lookup.
483  */
484 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
485 {
486         struct atalk_route *atr = atrtr_find(sa);
487         return atr ? atr->dev : NULL;
488 }
489
490 /* Set up a default router */
491 static void atrtr_set_default(struct net_device *dev)
492 {
493         atrtr_default.dev            = dev;
494         atrtr_default.flags          = RTF_UP;
495         atrtr_default.gateway.s_net  = htons(0);
496         atrtr_default.gateway.s_node = 0;
497 }
498
499 /*
500  * Add a router. Basically make sure it looks valid and stuff the
501  * entry in the list. While it uses netranges we always set them to one
502  * entry to work like netatalk.
503  */
504 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
505 {
506         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
507         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
508         struct atalk_route *rt;
509         struct atalk_iface *iface, *riface;
510         int retval = -EINVAL;
511
512         /*
513          * Fixme: Raise/Lower a routing change semaphore for these
514          * operations.
515          */
516
517         /* Validate the request */
518         if (ta->sat_family != AF_APPLETALK ||
519             (!devhint && ga->sat_family != AF_APPLETALK))
520                 goto out;
521
522         /* Now walk the routing table and make our decisions */
523         write_lock_bh(&atalk_routes_lock);
524         for (rt = atalk_routes; rt; rt = rt->next) {
525                 if (r->rt_flags != rt->flags)
526                         continue;
527
528                 if (ta->sat_addr.s_net == rt->target.s_net) {
529                         if (!(rt->flags & RTF_HOST))
530                                 break;
531                         if (ta->sat_addr.s_node == rt->target.s_node)
532                                 break;
533                 }
534         }
535
536         if (!devhint) {
537                 riface = NULL;
538
539                 read_lock_bh(&atalk_interfaces_lock);
540                 for (iface = atalk_interfaces; iface; iface = iface->next) {
541                         if (!riface &&
542                             ntohs(ga->sat_addr.s_net) >=
543                                         ntohs(iface->nets.nr_firstnet) &&
544                             ntohs(ga->sat_addr.s_net) <=
545                                         ntohs(iface->nets.nr_lastnet))
546                                 riface = iface;
547
548                         if (ga->sat_addr.s_net == iface->address.s_net &&
549                             ga->sat_addr.s_node == iface->address.s_node)
550                                 riface = iface;
551                 }
552                 read_unlock_bh(&atalk_interfaces_lock);
553
554                 retval = -ENETUNREACH;
555                 if (!riface)
556                         goto out_unlock;
557
558                 devhint = riface->dev;
559         }
560
561         if (!rt) {
562                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
563
564                 retval = -ENOBUFS;
565                 if (!rt)
566                         goto out_unlock;
567
568                 rt->next = atalk_routes;
569                 atalk_routes = rt;
570         }
571
572         /* Fill in the routing entry */
573         rt->target  = ta->sat_addr;
574         dev_hold(devhint);
575         rt->dev     = devhint;
576         rt->flags   = r->rt_flags;
577         rt->gateway = ga->sat_addr;
578
579         retval = 0;
580 out_unlock:
581         write_unlock_bh(&atalk_routes_lock);
582 out:
583         return retval;
584 }
585
586 /* Delete a route. Find it and discard it */
587 static int atrtr_delete(struct atalk_addr * addr)
588 {
589         struct atalk_route **r = &atalk_routes;
590         int retval = 0;
591         struct atalk_route *tmp;
592
593         write_lock_bh(&atalk_routes_lock);
594         while ((tmp = *r) != NULL) {
595                 if (tmp->target.s_net == addr->s_net &&
596                     (!(tmp->flags&RTF_GATEWAY) ||
597                      tmp->target.s_node == addr->s_node)) {
598                         *r = tmp->next;
599                         dev_put(tmp->dev);
600                         kfree(tmp);
601                         goto out;
602                 }
603                 r = &tmp->next;
604         }
605         retval = -ENOENT;
606 out:
607         write_unlock_bh(&atalk_routes_lock);
608         return retval;
609 }
610
611 /*
612  * Called when a device is downed. Just throw away any routes
613  * via it.
614  */
615 static void atrtr_device_down(struct net_device *dev)
616 {
617         struct atalk_route **r = &atalk_routes;
618         struct atalk_route *tmp;
619
620         write_lock_bh(&atalk_routes_lock);
621         while ((tmp = *r) != NULL) {
622                 if (tmp->dev == dev) {
623                         *r = tmp->next;
624                         dev_put(dev);
625                         kfree(tmp);
626                 } else
627                         r = &tmp->next;
628         }
629         write_unlock_bh(&atalk_routes_lock);
630
631         if (atrtr_default.dev == dev)
632                 atrtr_set_default(NULL);
633 }
634
635 /* Actually down the interface */
636 static inline void atalk_dev_down(struct net_device *dev)
637 {
638         atrtr_device_down(dev); /* Remove all routes for the device */
639         aarp_device_down(dev);  /* Remove AARP entries for the device */
640         atif_drop_device(dev);  /* Remove the device */
641 }
642
643 /*
644  * A device event has occurred. Watch for devices going down and
645  * delete our use of them (iface and route).
646  */
647 static int ddp_device_event(struct notifier_block *this, unsigned long event,
648                             void *ptr)
649 {
650         struct net_device *dev = ptr;
651
652         if (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(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                         if (!atif)
817                                 return -EADDRNOTAVAIL;
818
819                         /*
820                          * for now, we only support proxy AARP on ELAP;
821                          * we should be able to do it for LocalTalk, too.
822                          */
823                         if (dev->type != ARPHRD_ETHER)
824                                 return -EPROTONOSUPPORT;
825
826                         /*
827                          * atif points to the current interface on this network;
828                          * we aren't concerned about its current status (at
829                          * least for now), but it has all the settings about
830                          * the network we're going to probe. Consequently, it
831                          * must exist.
832                          */
833                         if (!atif)
834                                 return -EADDRNOTAVAIL;
835
836                         nr = (struct atalk_netrange *)&(atif->nets);
837                         /*
838                          * Phase 1 is fine on Localtalk but we don't do
839                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
840                          */
841                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
842                                 return -EPROTONOSUPPORT;
843
844                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
845                             sa->sat_addr.s_node == 254)
846                                 return -EINVAL;
847
848                         /*
849                          * Check if the chosen address is used. If so we
850                          * error and ATCP will try another.
851                          */
852                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
853                                 return -EADDRINUSE;
854
855                         /*
856                          * We now have an address on the local network, and
857                          * the AARP code will defend it for us until we take it
858                          * down. We don't set up any routes right now, because
859                          * ATCP will install them manually via SIOCADDRT.
860                          */
861                         break;
862
863                 case SIOCDARP:
864                         if (!capable(CAP_NET_ADMIN))
865                                 return -EPERM;
866                         if (sa->sat_family != AF_APPLETALK)
867                                 return -EINVAL;
868                         if (!atif)
869                                 return -EADDRNOTAVAIL;
870
871                         /* give to aarp module to remove proxy entry */
872                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
873                         return 0;
874         }
875
876         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
877 }
878
879 /* Routing ioctl() calls */
880 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
881 {
882         struct rtentry rt;
883
884         if (copy_from_user(&rt, arg, sizeof(rt)))
885                 return -EFAULT;
886
887         switch (cmd) {
888                 case SIOCDELRT:
889                         if (rt.rt_dst.sa_family != AF_APPLETALK)
890                                 return -EINVAL;
891                         return atrtr_delete(&((struct sockaddr_at *)
892                                                 &rt.rt_dst)->sat_addr);
893
894                 case SIOCADDRT: {
895                         struct net_device *dev = NULL;
896                         if (rt.rt_dev) {
897                                 char name[IFNAMSIZ];
898                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
899                                         return -EFAULT;
900                                 name[IFNAMSIZ-1] = '\0';
901                                 dev = __dev_get_by_name(name);
902                                 if (!dev)
903                                         return -ENODEV;
904                         }
905                         return atrtr_create(&rt, dev);
906                 }
907         }
908         return -EINVAL;
909 }
910
911 /**************************************************************************\
912 *                                                                          *
913 * Handling for system calls applied via the various interfaces to an       *
914 * AppleTalk socket object.                                                 *
915 *                                                                          *
916 \**************************************************************************/
917
918 /*
919  * Checksum: This is 'optional'. It's quite likely also a good
920  * candidate for assembler hackery 8)
921  */
922 static unsigned long atalk_sum_partial(const unsigned char *data,
923                                        int len, unsigned long sum)
924 {
925         /* This ought to be unwrapped neatly. I'll trust gcc for now */
926         while (len--) {
927                 sum += *data;
928                 sum <<= 1;
929                 if (sum & 0x10000) {
930                         sum++;
931                         sum &= 0xffff;
932                 }
933                 data++;
934         }
935         return sum;
936 }
937
938 /*  Checksum skb data --  similar to skb_checksum  */
939 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
940                                    int len, unsigned long sum)
941 {
942         int start = skb_headlen(skb);
943         int i, copy;
944
945         /* checksum stuff in header space */
946         if ( (copy = start - offset) > 0) {
947                 if (copy > len)
948                         copy = len;
949                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
950                 if ( (len -= copy) == 0)
951                         return sum;
952
953                 offset += copy;
954         }
955
956         /* checksum stuff in frags */
957         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
958                 int end;
959
960                 BUG_TRAP(start <= offset + len);
961
962                 end = start + skb_shinfo(skb)->frags[i].size;
963                 if ((copy = end - offset) > 0) {
964                         u8 *vaddr;
965                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
966
967                         if (copy > len)
968                                 copy = len;
969                         vaddr = kmap_skb_frag(frag);
970                         sum = atalk_sum_partial(vaddr + frag->page_offset +
971                                                   offset - start, copy, sum);
972                         kunmap_skb_frag(vaddr);
973
974                         if (!(len -= copy))
975                                 return sum;
976                         offset += copy;
977                 }
978                 start = end;
979         }
980
981         if (skb_shinfo(skb)->frag_list) {
982                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
983
984                 for (; list; list = list->next) {
985                         int end;
986
987                         BUG_TRAP(start <= offset + len);
988
989                         end = start + list->len;
990                         if ((copy = end - offset) > 0) {
991                                 if (copy > len)
992                                         copy = len;
993                                 sum = atalk_sum_skb(list, offset - start,
994                                                     copy, sum);
995                                 if ((len -= copy) == 0)
996                                         return sum;
997                                 offset += copy;
998                         }
999                         start = end;
1000                 }
1001         }
1002
1003         BUG_ON(len > 0);
1004
1005         return sum;
1006 }
1007
1008 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1009 {
1010         unsigned long sum;
1011
1012         /* skip header 4 bytes */
1013         sum = atalk_sum_skb(skb, 4, len-4, 0);
1014
1015         /* Use 0xFFFF for 0. 0 itself means none */
1016         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1017 }
1018
1019 static struct proto ddp_proto = {
1020         .name     = "DDP",
1021         .owner    = THIS_MODULE,
1022         .obj_size = sizeof(struct atalk_sock),
1023 };
1024
1025 /*
1026  * Create a socket. Initialise the socket, blank the addresses
1027  * set the state.
1028  */
1029 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1030 {
1031         struct sock *sk;
1032         int rc = -ESOCKTNOSUPPORT;
1033
1034         if (net != &init_net)
1035                 return -EAFNOSUPPORT;
1036
1037         /*
1038          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1039          * and gives you the full ELAP frame. Should be handy for CAP 8)
1040          */
1041         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1042                 goto out;
1043         rc = -ENOMEM;
1044         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1045         if (!sk)
1046                 goto out;
1047         rc = 0;
1048         sock->ops = &atalk_dgram_ops;
1049         sock_init_data(sock, sk);
1050
1051         /* Checksums on by default */
1052         sock_set_flag(sk, SOCK_ZAPPED);
1053 out:
1054         return rc;
1055 }
1056
1057 /* Free a socket. No work needed */
1058 static int atalk_release(struct socket *sock)
1059 {
1060         struct sock *sk = sock->sk;
1061
1062         if (sk) {
1063                 sock_orphan(sk);
1064                 sock->sk = NULL;
1065                 atalk_destroy_socket(sk);
1066         }
1067         return 0;
1068 }
1069
1070 /**
1071  * atalk_pick_and_bind_port - Pick a source port when one is not given
1072  * @sk - socket to insert into the tables
1073  * @sat - address to search for
1074  *
1075  * Pick a source port when one is not given. If we can find a suitable free
1076  * one, we insert the socket into the tables using it.
1077  *
1078  * This whole operation must be atomic.
1079  */
1080 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1081 {
1082         int retval;
1083
1084         write_lock_bh(&atalk_sockets_lock);
1085
1086         for (sat->sat_port = ATPORT_RESERVED;
1087              sat->sat_port < ATPORT_LAST;
1088              sat->sat_port++) {
1089                 struct sock *s;
1090                 struct hlist_node *node;
1091
1092                 sk_for_each(s, node, &atalk_sockets) {
1093                         struct atalk_sock *at = at_sk(s);
1094
1095                         if (at->src_net == sat->sat_addr.s_net &&
1096                             at->src_node == sat->sat_addr.s_node &&
1097                             at->src_port == sat->sat_port)
1098                                 goto try_next_port;
1099                 }
1100
1101                 /* Wheee, it's free, assign and insert. */
1102                 __atalk_insert_socket(sk);
1103                 at_sk(sk)->src_port = sat->sat_port;
1104                 retval = 0;
1105                 goto out;
1106
1107 try_next_port:;
1108         }
1109
1110         retval = -EBUSY;
1111 out:
1112         write_unlock_bh(&atalk_sockets_lock);
1113         return retval;
1114 }
1115
1116 static int atalk_autobind(struct sock *sk)
1117 {
1118         struct atalk_sock *at = at_sk(sk);
1119         struct sockaddr_at sat;
1120         struct atalk_addr *ap = atalk_find_primary();
1121         int n = -EADDRNOTAVAIL;
1122
1123         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1124                 goto out;
1125
1126         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1127         at->src_node = sat.sat_addr.s_node = ap->s_node;
1128
1129         n = atalk_pick_and_bind_port(sk, &sat);
1130         if (!n)
1131                 sock_reset_flag(sk, SOCK_ZAPPED);
1132 out:
1133         return n;
1134 }
1135
1136 /* Set the address 'our end' of the connection */
1137 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1138 {
1139         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1140         struct sock *sk = sock->sk;
1141         struct atalk_sock *at = at_sk(sk);
1142
1143         if (!sock_flag(sk, SOCK_ZAPPED) ||
1144             addr_len != sizeof(struct sockaddr_at))
1145                 return -EINVAL;
1146
1147         if (addr->sat_family != AF_APPLETALK)
1148                 return -EAFNOSUPPORT;
1149
1150         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1151                 struct atalk_addr *ap = atalk_find_primary();
1152
1153                 if (!ap)
1154                         return -EADDRNOTAVAIL;
1155
1156                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1157                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1158         } else {
1159                 if (!atalk_find_interface(addr->sat_addr.s_net,
1160                                           addr->sat_addr.s_node))
1161                         return -EADDRNOTAVAIL;
1162
1163                 at->src_net  = addr->sat_addr.s_net;
1164                 at->src_node = addr->sat_addr.s_node;
1165         }
1166
1167         if (addr->sat_port == ATADDR_ANYPORT) {
1168                 int n = atalk_pick_and_bind_port(sk, addr);
1169
1170                 if (n < 0)
1171                         return n;
1172         } else {
1173                 at->src_port = addr->sat_port;
1174
1175                 if (atalk_find_or_insert_socket(sk, addr))
1176                         return -EADDRINUSE;
1177         }
1178
1179         sock_reset_flag(sk, SOCK_ZAPPED);
1180         return 0;
1181 }
1182
1183 /* Set the address we talk to */
1184 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1185                          int addr_len, int flags)
1186 {
1187         struct sock *sk = sock->sk;
1188         struct atalk_sock *at = at_sk(sk);
1189         struct sockaddr_at *addr;
1190
1191         sk->sk_state   = TCP_CLOSE;
1192         sock->state = SS_UNCONNECTED;
1193
1194         if (addr_len != sizeof(*addr))
1195                 return -EINVAL;
1196
1197         addr = (struct sockaddr_at *)uaddr;
1198
1199         if (addr->sat_family != AF_APPLETALK)
1200                 return -EAFNOSUPPORT;
1201
1202         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1203             !sock_flag(sk, SOCK_BROADCAST)) {
1204 #if 1
1205                 printk(KERN_WARNING "%s is broken and did not set "
1206                                     "SO_BROADCAST. It will break when 2.2 is "
1207                                     "released.\n",
1208                         current->comm);
1209 #else
1210                 return -EACCES;
1211 #endif
1212         }
1213
1214         if (sock_flag(sk, SOCK_ZAPPED))
1215                 if (atalk_autobind(sk) < 0)
1216                         return -EBUSY;
1217
1218         if (!atrtr_get_dev(&addr->sat_addr))
1219                 return -ENETUNREACH;
1220
1221         at->dest_port = addr->sat_port;
1222         at->dest_net  = addr->sat_addr.s_net;
1223         at->dest_node = addr->sat_addr.s_node;
1224
1225         sock->state  = SS_CONNECTED;
1226         sk->sk_state = TCP_ESTABLISHED;
1227         return 0;
1228 }
1229
1230 /*
1231  * Find the name of an AppleTalk socket. Just copy the right
1232  * fields into the sockaddr.
1233  */
1234 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1235                          int *uaddr_len, int peer)
1236 {
1237         struct sockaddr_at sat;
1238         struct sock *sk = sock->sk;
1239         struct atalk_sock *at = at_sk(sk);
1240
1241         if (sock_flag(sk, SOCK_ZAPPED))
1242                 if (atalk_autobind(sk) < 0)
1243                         return -ENOBUFS;
1244
1245         *uaddr_len = sizeof(struct sockaddr_at);
1246
1247         if (peer) {
1248                 if (sk->sk_state != TCP_ESTABLISHED)
1249                         return -ENOTCONN;
1250
1251                 sat.sat_addr.s_net  = at->dest_net;
1252                 sat.sat_addr.s_node = at->dest_node;
1253                 sat.sat_port        = at->dest_port;
1254         } else {
1255                 sat.sat_addr.s_net  = at->src_net;
1256                 sat.sat_addr.s_node = at->src_node;
1257                 sat.sat_port        = at->src_port;
1258         }
1259
1260         sat.sat_family = AF_APPLETALK;
1261         memcpy(uaddr, &sat, sizeof(sat));
1262         return 0;
1263 }
1264
1265 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1266 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1267 {
1268         return skb->data[12] == 22;
1269 }
1270
1271 static int handle_ip_over_ddp(struct sk_buff *skb)
1272 {
1273         struct net_device *dev = __dev_get_by_name("ipddp0");
1274         struct net_device_stats *stats;
1275
1276         /* This needs to be able to handle ipddp"N" devices */
1277         if (!dev)
1278                 return -ENODEV;
1279
1280         skb->protocol = htons(ETH_P_IP);
1281         skb_pull(skb, 13);
1282         skb->dev   = dev;
1283         skb_reset_transport_header(skb);
1284
1285         stats = dev->priv;
1286         stats->rx_packets++;
1287         stats->rx_bytes += skb->len + 13;
1288         netif_rx(skb);  /* Send the SKB up to a higher place. */
1289         return 0;
1290 }
1291 #else
1292 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1293 #define is_ip_over_ddp(skb) 0
1294 #define handle_ip_over_ddp(skb) 0
1295 #endif
1296
1297 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1298                                struct ddpehdr *ddp, __u16 len_hops,
1299                                int origlen)
1300 {
1301         struct atalk_route *rt;
1302         struct atalk_addr ta;
1303
1304         /*
1305          * Don't route multicast, etc., packets, or packets sent to "this
1306          * network"
1307          */
1308         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1309                 /*
1310                  * FIXME:
1311                  *
1312                  * Can it ever happen that a packet is from a PPP iface and
1313                  * needs to be broadcast onto the default network?
1314                  */
1315                 if (dev->type == ARPHRD_PPP)
1316                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1317                                           "packet received from PPP iface\n");
1318                 goto free_it;
1319         }
1320
1321         ta.s_net  = ddp->deh_dnet;
1322         ta.s_node = ddp->deh_dnode;
1323
1324         /* Route the packet */
1325         rt = atrtr_find(&ta);
1326         /* increment hops count */
1327         len_hops += 1 << 10;
1328         if (!rt || !(len_hops & (15 << 10)))
1329                 goto free_it;
1330
1331         /* FIXME: use skb->cb to be able to use shared skbs */
1332
1333         /*
1334          * Route goes through another gateway, so set the target to the
1335          * gateway instead.
1336          */
1337
1338         if (rt->flags & RTF_GATEWAY) {
1339                 ta.s_net  = rt->gateway.s_net;
1340                 ta.s_node = rt->gateway.s_node;
1341         }
1342
1343         /* Fix up skb->len field */
1344         skb_trim(skb, min_t(unsigned int, origlen,
1345                             (rt->dev->hard_header_len +
1346                              ddp_dl->header_length + (len_hops & 1023))));
1347
1348         /* FIXME: use skb->cb to be able to use shared skbs */
1349         ddp->deh_len_hops = htons(len_hops);
1350
1351         /*
1352          * Send the buffer onwards
1353          *
1354          * Now we must always be careful. If it's come from LocalTalk to
1355          * EtherTalk it might not fit
1356          *
1357          * Order matters here: If a packet has to be copied to make a new
1358          * headroom (rare hopefully) then it won't need unsharing.
1359          *
1360          * Note. ddp-> becomes invalid at the realloc.
1361          */
1362         if (skb_headroom(skb) < 22) {
1363                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1364                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1365                 kfree_skb(skb);
1366                 if (!nskb)
1367                         goto out;
1368                 skb = nskb;
1369         } else
1370                 skb = skb_unshare(skb, GFP_ATOMIC);
1371
1372         /*
1373          * If the buffer didn't vanish into the lack of space bitbucket we can
1374          * send it.
1375          */
1376         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1377                 goto free_it;
1378 out:
1379         return;
1380 free_it:
1381         kfree_skb(skb);
1382 }
1383
1384 /**
1385  *      atalk_rcv - Receive a packet (in skb) from device dev
1386  *      @skb - packet received
1387  *      @dev - network device where the packet comes from
1388  *      @pt - packet type
1389  *
1390  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1391  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1392  *      is the DDP header, skb->len is the DDP length. The physical headers
1393  *      have been extracted. PPP should probably pass frames marked as for this
1394  *      layer.  [ie ARPHRD_ETHERTALK]
1395  */
1396 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1397                      struct packet_type *pt, struct net_device *orig_dev)
1398 {
1399         struct ddpehdr *ddp;
1400         struct sock *sock;
1401         struct atalk_iface *atif;
1402         struct sockaddr_at tosat;
1403         int origlen;
1404         __u16 len_hops;
1405
1406         if (dev->nd_net != &init_net)
1407                 goto freeit;
1408
1409         /* Don't mangle buffer if shared */
1410         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1411                 goto out;
1412
1413         /* Size check and make sure header is contiguous */
1414         if (!pskb_may_pull(skb, sizeof(*ddp)))
1415                 goto freeit;
1416
1417         ddp = ddp_hdr(skb);
1418
1419         len_hops = ntohs(ddp->deh_len_hops);
1420
1421         /* Trim buffer in case of stray trailing data */
1422         origlen = skb->len;
1423         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1424
1425         /*
1426          * Size check to see if ddp->deh_len was crap
1427          * (Otherwise we'll detonate most spectacularly
1428          * in the middle of atalk_checksum() or recvmsg()).
1429          */
1430         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1431                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1432                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1433                 goto freeit;
1434         }
1435
1436         /*
1437          * Any checksums. Note we don't do htons() on this == is assumed to be
1438          * valid for net byte orders all over the networking code...
1439          */
1440         if (ddp->deh_sum &&
1441             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1442                 /* Not a valid AppleTalk frame - dustbin time */
1443                 goto freeit;
1444
1445         /* Check the packet is aimed at us */
1446         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1447                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1448         else
1449                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1450
1451         if (!atif) {
1452                 /* Not ours, so we route the packet via the correct
1453                  * AppleTalk iface
1454                  */
1455                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1456                 goto out;
1457         }
1458
1459         /* if IP over DDP is not selected this code will be optimized out */
1460         if (is_ip_over_ddp(skb))
1461                 return handle_ip_over_ddp(skb);
1462         /*
1463          * Which socket - atalk_search_socket() looks for a *full match*
1464          * of the <net, node, port> tuple.
1465          */
1466         tosat.sat_addr.s_net  = ddp->deh_dnet;
1467         tosat.sat_addr.s_node = ddp->deh_dnode;
1468         tosat.sat_port        = ddp->deh_dport;
1469
1470         sock = atalk_search_socket(&tosat, atif);
1471         if (!sock) /* But not one of our sockets */
1472                 goto freeit;
1473
1474         /* Queue packet (standard) */
1475         skb->sk = sock;
1476
1477         if (sock_queue_rcv_skb(sock, skb) < 0)
1478                 goto freeit;
1479 out:
1480         return 0;
1481 freeit:
1482         kfree_skb(skb);
1483         goto out;
1484 }
1485
1486 /*
1487  * Receive a LocalTalk frame. We make some demands on the caller here.
1488  * Caller must provide enough headroom on the packet to pull the short
1489  * header and append a long one.
1490  */
1491 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1492                      struct packet_type *pt, struct net_device *orig_dev)
1493 {
1494         if (dev->nd_net != &init_net)
1495                 goto freeit;
1496
1497         /* Expand any short form frames */
1498         if (skb_mac_header(skb)[2] == 1) {
1499                 struct ddpehdr *ddp;
1500                 /* Find our address */
1501                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1502
1503                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1504                         goto freeit;
1505
1506                 /* Don't mangle buffer if shared */
1507                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1508                         return 0;
1509
1510                 /*
1511                  * The push leaves us with a ddephdr not an shdr, and
1512                  * handily the port bytes in the right place preset.
1513                  */
1514                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1515
1516                 /* Now fill in the long header */
1517
1518                 /*
1519                  * These two first. The mac overlays the new source/dest
1520                  * network information so we MUST copy these before
1521                  * we write the network numbers !
1522                  */
1523
1524                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1525                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1526
1527                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1528                 ddp->deh_snet  = ap->s_net;
1529                 ddp->deh_sum   = 0;             /* No checksum */
1530                 /*
1531                  * Not sure about this bit...
1532                  */
1533                 /* Non routable, so force a drop if we slip up later */
1534                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1535         }
1536         skb_reset_transport_header(skb);
1537
1538         return atalk_rcv(skb, dev, pt, orig_dev);
1539 freeit:
1540         kfree_skb(skb);
1541         return 0;
1542 }
1543
1544 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1545                          size_t len)
1546 {
1547         struct sock *sk = sock->sk;
1548         struct atalk_sock *at = at_sk(sk);
1549         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1550         int flags = msg->msg_flags;
1551         int loopback = 0;
1552         struct sockaddr_at local_satalk, gsat;
1553         struct sk_buff *skb;
1554         struct net_device *dev;
1555         struct ddpehdr *ddp;
1556         int size;
1557         struct atalk_route *rt;
1558         int err;
1559
1560         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1561                 return -EINVAL;
1562
1563         if (len > DDP_MAXSZ)
1564                 return -EMSGSIZE;
1565
1566         if (usat) {
1567                 if (sock_flag(sk, SOCK_ZAPPED))
1568                         if (atalk_autobind(sk) < 0)
1569                                 return -EBUSY;
1570
1571                 if (msg->msg_namelen < sizeof(*usat) ||
1572                     usat->sat_family != AF_APPLETALK)
1573                         return -EINVAL;
1574
1575                 /* netatalk doesn't implement this check */
1576                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1577                     !sock_flag(sk, SOCK_BROADCAST)) {
1578                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1579                                          "it will break before 2.2\n");
1580 #if 0
1581                         return -EPERM;
1582 #endif
1583                 }
1584         } else {
1585                 if (sk->sk_state != TCP_ESTABLISHED)
1586                         return -ENOTCONN;
1587                 usat = &local_satalk;
1588                 usat->sat_family      = AF_APPLETALK;
1589                 usat->sat_port        = at->dest_port;
1590                 usat->sat_addr.s_node = at->dest_node;
1591                 usat->sat_addr.s_net  = at->dest_net;
1592         }
1593
1594         /* Build a packet */
1595         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1596
1597         /* For headers */
1598         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1599
1600         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1601                 rt = atrtr_find(&usat->sat_addr);
1602         } else {
1603                 struct atalk_addr at_hint;
1604
1605                 at_hint.s_node = 0;
1606                 at_hint.s_net  = at->src_net;
1607
1608                 rt = atrtr_find(&at_hint);
1609         }
1610         if (!rt)
1611                 return -ENETUNREACH;
1612
1613         dev = rt->dev;
1614
1615         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1616                         sk, size, dev->name);
1617
1618         size += dev->hard_header_len;
1619         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1620         if (!skb)
1621                 return err;
1622
1623         skb->sk = sk;
1624         skb_reserve(skb, ddp_dl->header_length);
1625         skb_reserve(skb, dev->hard_header_len);
1626         skb->dev = dev;
1627
1628         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1629
1630         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1631         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1632         ddp->deh_dnet  = usat->sat_addr.s_net;
1633         ddp->deh_snet  = at->src_net;
1634         ddp->deh_dnode = usat->sat_addr.s_node;
1635         ddp->deh_snode = at->src_node;
1636         ddp->deh_dport = usat->sat_port;
1637         ddp->deh_sport = at->src_port;
1638
1639         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1640
1641         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1642         if (err) {
1643                 kfree_skb(skb);
1644                 return -EFAULT;
1645         }
1646
1647         if (sk->sk_no_check == 1)
1648                 ddp->deh_sum = 0;
1649         else
1650                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1651
1652         /*
1653          * Loopback broadcast packets to non gateway targets (ie routes
1654          * to group we are in)
1655          */
1656         if (ddp->deh_dnode == ATADDR_BCAST &&
1657             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1658                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1659
1660                 if (skb2) {
1661                         loopback = 1;
1662                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1663                         if (aarp_send_ddp(dev, skb2,
1664                                           &usat->sat_addr, NULL) == -1)
1665                                 kfree_skb(skb2);
1666                                 /* else queued/sent above in the aarp queue */
1667                 }
1668         }
1669
1670         if (dev->flags & IFF_LOOPBACK || loopback) {
1671                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1672                 /* loop back */
1673                 skb_orphan(skb);
1674                 if (ddp->deh_dnode == ATADDR_BCAST) {
1675                         struct atalk_addr at_lo;
1676
1677                         at_lo.s_node = 0;
1678                         at_lo.s_net  = 0;
1679
1680                         rt = atrtr_find(&at_lo);
1681                         if (!rt) {
1682                                 kfree_skb(skb);
1683                                 return -ENETUNREACH;
1684                         }
1685                         dev = rt->dev;
1686                         skb->dev = dev;
1687                 }
1688                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1689         } else {
1690                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1691                 if (rt->flags & RTF_GATEWAY) {
1692                     gsat.sat_addr = rt->gateway;
1693                     usat = &gsat;
1694                 }
1695
1696                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1697                         kfree_skb(skb);
1698                 /* else queued/sent above in the aarp queue */
1699         }
1700         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1701
1702         return len;
1703 }
1704
1705 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1706                          size_t size, int flags)
1707 {
1708         struct sock *sk = sock->sk;
1709         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1710         struct ddpehdr *ddp;
1711         int copied = 0;
1712         int offset = 0;
1713         int err = 0;
1714         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1715                                                 flags & MSG_DONTWAIT, &err);
1716         if (!skb)
1717                 return err;
1718
1719         /* FIXME: use skb->cb to be able to use shared skbs */
1720         ddp = ddp_hdr(skb);
1721         copied = ntohs(ddp->deh_len_hops) & 1023;
1722
1723         if (sk->sk_type != SOCK_RAW) {
1724                 offset = sizeof(*ddp);
1725                 copied -= offset;
1726         }
1727
1728         if (copied > size) {
1729                 copied = size;
1730                 msg->msg_flags |= MSG_TRUNC;
1731         }
1732         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1733
1734         if (!err) {
1735                 if (sat) {
1736                         sat->sat_family      = AF_APPLETALK;
1737                         sat->sat_port        = ddp->deh_sport;
1738                         sat->sat_addr.s_node = ddp->deh_snode;
1739                         sat->sat_addr.s_net  = ddp->deh_snet;
1740                 }
1741                 msg->msg_namelen = sizeof(*sat);
1742         }
1743
1744         skb_free_datagram(sk, skb);     /* Free the datagram. */
1745         return err ? : copied;
1746 }
1747
1748
1749 /*
1750  * AppleTalk ioctl calls.
1751  */
1752 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1753 {
1754         int rc = -ENOIOCTLCMD;
1755         struct sock *sk = sock->sk;
1756         void __user *argp = (void __user *)arg;
1757
1758         switch (cmd) {
1759                 /* Protocol layer */
1760                 case TIOCOUTQ: {
1761                         long amount = sk->sk_sndbuf -
1762                                       atomic_read(&sk->sk_wmem_alloc);
1763
1764                         if (amount < 0)
1765                                 amount = 0;
1766                         rc = put_user(amount, (int __user *)argp);
1767                         break;
1768                 }
1769                 case TIOCINQ: {
1770                         /*
1771                          * These two are safe on a single CPU system as only
1772                          * user tasks fiddle here
1773                          */
1774                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1775                         long amount = 0;
1776
1777                         if (skb)
1778                                 amount = skb->len - sizeof(struct ddpehdr);
1779                         rc = put_user(amount, (int __user *)argp);
1780                         break;
1781                 }
1782                 case SIOCGSTAMP:
1783                         rc = sock_get_timestamp(sk, argp);
1784                         break;
1785                 case SIOCGSTAMPNS:
1786                         rc = sock_get_timestampns(sk, argp);
1787                         break;
1788                 /* Routing */
1789                 case SIOCADDRT:
1790                 case SIOCDELRT:
1791                         rc = -EPERM;
1792                         if (capable(CAP_NET_ADMIN))
1793                                 rc = atrtr_ioctl(cmd, argp);
1794                         break;
1795                 /* Interface */
1796                 case SIOCGIFADDR:
1797                 case SIOCSIFADDR:
1798                 case SIOCGIFBRDADDR:
1799                 case SIOCATALKDIFADDR:
1800                 case SIOCDIFADDR:
1801                 case SIOCSARP:          /* proxy AARP */
1802                 case SIOCDARP:          /* proxy AARP */
1803                         rtnl_lock();
1804                         rc = atif_ioctl(cmd, argp);
1805                         rtnl_unlock();
1806                         break;
1807         }
1808
1809         return rc;
1810 }
1811
1812
1813 #ifdef CONFIG_COMPAT
1814 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1815 {
1816         /*
1817          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1818          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1819          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1820          * here so there is no generic SIOCPROTOPRIVATE translation in the
1821          * system.
1822          */
1823         return -ENOIOCTLCMD;
1824 }
1825 #endif
1826
1827
1828 static struct net_proto_family atalk_family_ops = {
1829         .family         = PF_APPLETALK,
1830         .create         = atalk_create,
1831         .owner          = THIS_MODULE,
1832 };
1833
1834 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1835         .family         = PF_APPLETALK,
1836         .owner          = THIS_MODULE,
1837         .release        = atalk_release,
1838         .bind           = atalk_bind,
1839         .connect        = atalk_connect,
1840         .socketpair     = sock_no_socketpair,
1841         .accept         = sock_no_accept,
1842         .getname        = atalk_getname,
1843         .poll           = datagram_poll,
1844         .ioctl          = atalk_ioctl,
1845 #ifdef CONFIG_COMPAT
1846         .compat_ioctl   = atalk_compat_ioctl,
1847 #endif
1848         .listen         = sock_no_listen,
1849         .shutdown       = sock_no_shutdown,
1850         .setsockopt     = sock_no_setsockopt,
1851         .getsockopt     = sock_no_getsockopt,
1852         .sendmsg        = atalk_sendmsg,
1853         .recvmsg        = atalk_recvmsg,
1854         .mmap           = sock_no_mmap,
1855         .sendpage       = sock_no_sendpage,
1856 };
1857
1858 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1859
1860 static struct notifier_block ddp_notifier = {
1861         .notifier_call  = ddp_device_event,
1862 };
1863
1864 static struct packet_type ltalk_packet_type = {
1865         .type           = __constant_htons(ETH_P_LOCALTALK),
1866         .func           = ltalk_rcv,
1867 };
1868
1869 static struct packet_type ppptalk_packet_type = {
1870         .type           = __constant_htons(ETH_P_PPPTALK),
1871         .func           = atalk_rcv,
1872 };
1873
1874 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1875
1876 /* Export symbols for use by drivers when AppleTalk is a module */
1877 EXPORT_SYMBOL(aarp_send_ddp);
1878 EXPORT_SYMBOL(atrtr_get_dev);
1879 EXPORT_SYMBOL(atalk_find_dev_addr);
1880
1881 static char atalk_err_snap[] __initdata =
1882         KERN_CRIT "Unable to register DDP with SNAP.\n";
1883
1884 /* Called by proto.c on kernel start up */
1885 static int __init atalk_init(void)
1886 {
1887         int rc = proto_register(&ddp_proto, 0);
1888
1889         if (rc != 0)
1890                 goto out;
1891
1892         (void)sock_register(&atalk_family_ops);
1893         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1894         if (!ddp_dl)
1895                 printk(atalk_err_snap);
1896
1897         dev_add_pack(&ltalk_packet_type);
1898         dev_add_pack(&ppptalk_packet_type);
1899
1900         register_netdevice_notifier(&ddp_notifier);
1901         aarp_proto_init();
1902         atalk_proc_init();
1903         atalk_register_sysctl();
1904 out:
1905         return rc;
1906 }
1907 module_init(atalk_init);
1908
1909 /*
1910  * No explicit module reference count manipulation is needed in the
1911  * protocol. Socket layer sets module reference count for us
1912  * and interfaces reference counting is done
1913  * by the network device layer.
1914  *
1915  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1916  * sockets be closed from user space.
1917  */
1918 static void __exit atalk_exit(void)
1919 {
1920 #ifdef CONFIG_SYSCTL
1921         atalk_unregister_sysctl();
1922 #endif /* CONFIG_SYSCTL */
1923         atalk_proc_exit();
1924         aarp_cleanup_module();  /* General aarp clean-up. */
1925         unregister_netdevice_notifier(&ddp_notifier);
1926         dev_remove_pack(&ltalk_packet_type);
1927         dev_remove_pack(&ppptalk_packet_type);
1928         unregister_snap_client(ddp_dl);
1929         sock_unregister(PF_APPLETALK);
1930         proto_unregister(&ddp_proto);
1931 }
1932 module_exit(atalk_exit);
1933
1934 MODULE_LICENSE("GPL");
1935 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1936 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1937 MODULE_ALIAS_NETPROTO(PF_APPLETALK);