net: convert BUG_TRAP to generic WARN_ON
[linux-3.10.git] / 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                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
181                                 (unsigned long)sk);
182                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
183                 add_timer(&sk->sk_timer);
184         } else
185                 sock_put(sk);
186 }
187
188 /**************************************************************************\
189 *                                                                          *
190 * Routing tables for the AppleTalk socket layer.                           *
191 *                                                                          *
192 \**************************************************************************/
193
194 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
195 struct atalk_route *atalk_routes;
196 DEFINE_RWLOCK(atalk_routes_lock);
197
198 struct atalk_iface *atalk_interfaces;
199 DEFINE_RWLOCK(atalk_interfaces_lock);
200
201 /* For probing devices or in a routerless network */
202 struct atalk_route atrtr_default;
203
204 /* AppleTalk interface control */
205 /*
206  * Drop a device. Doesn't drop any of its routes - that is the caller's
207  * problem. Called when we down the interface or delete the address.
208  */
209 static void atif_drop_device(struct net_device *dev)
210 {
211         struct atalk_iface **iface = &atalk_interfaces;
212         struct atalk_iface *tmp;
213
214         write_lock_bh(&atalk_interfaces_lock);
215         while ((tmp = *iface) != NULL) {
216                 if (tmp->dev == dev) {
217                         *iface = tmp->next;
218                         dev_put(dev);
219                         kfree(tmp);
220                         dev->atalk_ptr = NULL;
221                 } else
222                         iface = &tmp->next;
223         }
224         write_unlock_bh(&atalk_interfaces_lock);
225 }
226
227 static struct atalk_iface *atif_add_device(struct net_device *dev,
228                                            struct atalk_addr *sa)
229 {
230         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
231
232         if (!iface)
233                 goto out;
234
235         dev_hold(dev);
236         iface->dev = dev;
237         dev->atalk_ptr = iface;
238         iface->address = *sa;
239         iface->status = 0;
240
241         write_lock_bh(&atalk_interfaces_lock);
242         iface->next = atalk_interfaces;
243         atalk_interfaces = iface;
244         write_unlock_bh(&atalk_interfaces_lock);
245 out:
246         return iface;
247 }
248
249 /* Perform phase 2 AARP probing on our tentative address */
250 static int atif_probe_device(struct atalk_iface *atif)
251 {
252         int netrange = ntohs(atif->nets.nr_lastnet) -
253                         ntohs(atif->nets.nr_firstnet) + 1;
254         int probe_net = ntohs(atif->address.s_net);
255         int probe_node = atif->address.s_node;
256         int netct, nodect;
257
258         /* Offset the network we start probing with */
259         if (probe_net == ATADDR_ANYNET) {
260                 probe_net = ntohs(atif->nets.nr_firstnet);
261                 if (netrange)
262                         probe_net += jiffies % netrange;
263         }
264         if (probe_node == ATADDR_ANYNODE)
265                 probe_node = jiffies & 0xFF;
266
267         /* Scan the networks */
268         atif->status |= ATIF_PROBE;
269         for (netct = 0; netct <= netrange; netct++) {
270                 /* Sweep the available nodes from a given start */
271                 atif->address.s_net = htons(probe_net);
272                 for (nodect = 0; nodect < 256; nodect++) {
273                         atif->address.s_node = (nodect + probe_node) & 0xFF;
274                         if (atif->address.s_node > 0 &&
275                             atif->address.s_node < 254) {
276                                 /* Probe a proposed address */
277                                 aarp_probe_network(atif);
278
279                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
280                                         atif->status &= ~ATIF_PROBE;
281                                         return 0;
282                                 }
283                         }
284                         atif->status &= ~ATIF_PROBE_FAIL;
285                 }
286                 probe_net++;
287                 if (probe_net > ntohs(atif->nets.nr_lastnet))
288                         probe_net = ntohs(atif->nets.nr_firstnet);
289         }
290         atif->status &= ~ATIF_PROBE;
291
292         return -EADDRINUSE;     /* Network is full... */
293 }
294
295
296 /* Perform AARP probing for a proxy address */
297 static int atif_proxy_probe_device(struct atalk_iface *atif,
298                                    struct atalk_addr* proxy_addr)
299 {
300         int netrange = ntohs(atif->nets.nr_lastnet) -
301                         ntohs(atif->nets.nr_firstnet) + 1;
302         /* we probe the interface's network */
303         int probe_net = ntohs(atif->address.s_net);
304         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
305         int netct, nodect;
306
307         /* Offset the network we start probing with */
308         if (probe_net == ATADDR_ANYNET) {
309                 probe_net = ntohs(atif->nets.nr_firstnet);
310                 if (netrange)
311                         probe_net += jiffies % netrange;
312         }
313
314         if (probe_node == ATADDR_ANYNODE)
315                 probe_node = jiffies & 0xFF;
316
317         /* Scan the networks */
318         for (netct = 0; netct <= netrange; netct++) {
319                 /* Sweep the available nodes from a given start */
320                 proxy_addr->s_net = htons(probe_net);
321                 for (nodect = 0; nodect < 256; nodect++) {
322                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
323                         if (proxy_addr->s_node > 0 &&
324                             proxy_addr->s_node < 254) {
325                                 /* Tell AARP to probe a proposed address */
326                                 int ret = aarp_proxy_probe_network(atif,
327                                                                     proxy_addr);
328
329                                 if (ret != -EADDRINUSE)
330                                         return ret;
331                         }
332                 }
333                 probe_net++;
334                 if (probe_net > ntohs(atif->nets.nr_lastnet))
335                         probe_net = ntohs(atif->nets.nr_firstnet);
336         }
337
338         return -EADDRINUSE;     /* Network is full... */
339 }
340
341
342 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
343 {
344         struct atalk_iface *iface = dev->atalk_ptr;
345         return iface ? &iface->address : NULL;
346 }
347
348 static struct atalk_addr *atalk_find_primary(void)
349 {
350         struct atalk_iface *fiface = NULL;
351         struct atalk_addr *retval;
352         struct atalk_iface *iface;
353
354         /*
355          * Return a point-to-point interface only if
356          * there is no non-ptp interface available.
357          */
358         read_lock_bh(&atalk_interfaces_lock);
359         for (iface = atalk_interfaces; iface; iface = iface->next) {
360                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
361                         fiface = iface;
362                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
363                         retval = &iface->address;
364                         goto out;
365                 }
366         }
367
368         if (fiface)
369                 retval = &fiface->address;
370         else if (atalk_interfaces)
371                 retval = &atalk_interfaces->address;
372         else
373                 retval = NULL;
374 out:
375         read_unlock_bh(&atalk_interfaces_lock);
376         return retval;
377 }
378
379 /*
380  * Find a match for 'any network' - ie any of our interfaces with that
381  * node number will do just nicely.
382  */
383 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
384 {
385         struct atalk_iface *iface = dev->atalk_ptr;
386
387         if (!iface || iface->status & ATIF_PROBE)
388                 goto out_err;
389
390         if (node != ATADDR_BCAST &&
391             iface->address.s_node != node &&
392             node != ATADDR_ANYNODE)
393                 goto out_err;
394 out:
395         return iface;
396 out_err:
397         iface = NULL;
398         goto out;
399 }
400
401 /* Find a match for a specific network:node pair */
402 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
403 {
404         struct atalk_iface *iface;
405
406         read_lock_bh(&atalk_interfaces_lock);
407         for (iface = atalk_interfaces; iface; iface = iface->next) {
408                 if ((node == ATADDR_BCAST ||
409                      node == ATADDR_ANYNODE ||
410                      iface->address.s_node == node) &&
411                     iface->address.s_net == net &&
412                     !(iface->status & ATIF_PROBE))
413                         break;
414
415                 /* XXXX.0 -- net.0 returns the iface associated with net */
416                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
417                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
418                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
419                         break;
420         }
421         read_unlock_bh(&atalk_interfaces_lock);
422         return iface;
423 }
424
425
426 /*
427  * Find a route for an AppleTalk packet. This ought to get cached in
428  * the socket (later on...). We know about host routes and the fact
429  * that a route must be direct to broadcast.
430  */
431 static struct atalk_route *atrtr_find(struct atalk_addr *target)
432 {
433         /*
434          * we must search through all routes unless we find a
435          * host route, because some host routes might overlap
436          * network routes
437          */
438         struct atalk_route *net_route = NULL;
439         struct atalk_route *r;
440
441         read_lock_bh(&atalk_routes_lock);
442         for (r = atalk_routes; r; r = r->next) {
443                 if (!(r->flags & RTF_UP))
444                         continue;
445
446                 if (r->target.s_net == target->s_net) {
447                         if (r->flags & RTF_HOST) {
448                                 /*
449                                  * if this host route is for the target,
450                                  * the we're done
451                                  */
452                                 if (r->target.s_node == target->s_node)
453                                         goto out;
454                         } else
455                                 /*
456                                  * this route will work if there isn't a
457                                  * direct host route, so cache it
458                                  */
459                                 net_route = r;
460                 }
461         }
462
463         /*
464          * if we found a network route but not a direct host
465          * route, then return it
466          */
467         if (net_route)
468                 r = net_route;
469         else if (atrtr_default.dev)
470                 r = &atrtr_default;
471         else /* No route can be found */
472                 r = NULL;
473 out:
474         read_unlock_bh(&atalk_routes_lock);
475         return r;
476 }
477
478
479 /*
480  * Given an AppleTalk network, find the device to use. This can be
481  * a simple lookup.
482  */
483 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
484 {
485         struct atalk_route *atr = atrtr_find(sa);
486         return atr ? atr->dev : NULL;
487 }
488
489 /* Set up a default router */
490 static void atrtr_set_default(struct net_device *dev)
491 {
492         atrtr_default.dev            = dev;
493         atrtr_default.flags          = RTF_UP;
494         atrtr_default.gateway.s_net  = htons(0);
495         atrtr_default.gateway.s_node = 0;
496 }
497
498 /*
499  * Add a router. Basically make sure it looks valid and stuff the
500  * entry in the list. While it uses netranges we always set them to one
501  * entry to work like netatalk.
502  */
503 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
504 {
505         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
506         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
507         struct atalk_route *rt;
508         struct atalk_iface *iface, *riface;
509         int retval = -EINVAL;
510
511         /*
512          * Fixme: Raise/Lower a routing change semaphore for these
513          * operations.
514          */
515
516         /* Validate the request */
517         if (ta->sat_family != AF_APPLETALK ||
518             (!devhint && ga->sat_family != AF_APPLETALK))
519                 goto out;
520
521         /* Now walk the routing table and make our decisions */
522         write_lock_bh(&atalk_routes_lock);
523         for (rt = atalk_routes; rt; rt = rt->next) {
524                 if (r->rt_flags != rt->flags)
525                         continue;
526
527                 if (ta->sat_addr.s_net == rt->target.s_net) {
528                         if (!(rt->flags & RTF_HOST))
529                                 break;
530                         if (ta->sat_addr.s_node == rt->target.s_node)
531                                 break;
532                 }
533         }
534
535         if (!devhint) {
536                 riface = NULL;
537
538                 read_lock_bh(&atalk_interfaces_lock);
539                 for (iface = atalk_interfaces; iface; iface = iface->next) {
540                         if (!riface &&
541                             ntohs(ga->sat_addr.s_net) >=
542                                         ntohs(iface->nets.nr_firstnet) &&
543                             ntohs(ga->sat_addr.s_net) <=
544                                         ntohs(iface->nets.nr_lastnet))
545                                 riface = iface;
546
547                         if (ga->sat_addr.s_net == iface->address.s_net &&
548                             ga->sat_addr.s_node == iface->address.s_node)
549                                 riface = iface;
550                 }
551                 read_unlock_bh(&atalk_interfaces_lock);
552
553                 retval = -ENETUNREACH;
554                 if (!riface)
555                         goto out_unlock;
556
557                 devhint = riface->dev;
558         }
559
560         if (!rt) {
561                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
562
563                 retval = -ENOBUFS;
564                 if (!rt)
565                         goto out_unlock;
566
567                 rt->next = atalk_routes;
568                 atalk_routes = rt;
569         }
570
571         /* Fill in the routing entry */
572         rt->target  = ta->sat_addr;
573         dev_hold(devhint);
574         rt->dev     = devhint;
575         rt->flags   = r->rt_flags;
576         rt->gateway = ga->sat_addr;
577
578         retval = 0;
579 out_unlock:
580         write_unlock_bh(&atalk_routes_lock);
581 out:
582         return retval;
583 }
584
585 /* Delete a route. Find it and discard it */
586 static int atrtr_delete(struct atalk_addr * addr)
587 {
588         struct atalk_route **r = &atalk_routes;
589         int retval = 0;
590         struct atalk_route *tmp;
591
592         write_lock_bh(&atalk_routes_lock);
593         while ((tmp = *r) != NULL) {
594                 if (tmp->target.s_net == addr->s_net &&
595                     (!(tmp->flags&RTF_GATEWAY) ||
596                      tmp->target.s_node == addr->s_node)) {
597                         *r = tmp->next;
598                         dev_put(tmp->dev);
599                         kfree(tmp);
600                         goto out;
601                 }
602                 r = &tmp->next;
603         }
604         retval = -ENOENT;
605 out:
606         write_unlock_bh(&atalk_routes_lock);
607         return retval;
608 }
609
610 /*
611  * Called when a device is downed. Just throw away any routes
612  * via it.
613  */
614 static void atrtr_device_down(struct net_device *dev)
615 {
616         struct atalk_route **r = &atalk_routes;
617         struct atalk_route *tmp;
618
619         write_lock_bh(&atalk_routes_lock);
620         while ((tmp = *r) != NULL) {
621                 if (tmp->dev == dev) {
622                         *r = tmp->next;
623                         dev_put(dev);
624                         kfree(tmp);
625                 } else
626                         r = &tmp->next;
627         }
628         write_unlock_bh(&atalk_routes_lock);
629
630         if (atrtr_default.dev == dev)
631                 atrtr_set_default(NULL);
632 }
633
634 /* Actually down the interface */
635 static inline void atalk_dev_down(struct net_device *dev)
636 {
637         atrtr_device_down(dev); /* Remove all routes for the device */
638         aarp_device_down(dev);  /* Remove AARP entries for the device */
639         atif_drop_device(dev);  /* Remove the device */
640 }
641
642 /*
643  * A device event has occurred. Watch for devices going down and
644  * delete our use of them (iface and route).
645  */
646 static int ddp_device_event(struct notifier_block *this, unsigned long event,
647                             void *ptr)
648 {
649         struct net_device *dev = ptr;
650
651         if (!net_eq(dev_net(dev), &init_net))
652                 return NOTIFY_DONE;
653
654         if (event == NETDEV_DOWN)
655                 /* Discard any use of this */
656                 atalk_dev_down(dev);
657
658         return NOTIFY_DONE;
659 }
660
661 /* ioctl calls. Shouldn't even need touching */
662 /* Device configuration ioctl calls */
663 static int atif_ioctl(int cmd, void __user *arg)
664 {
665         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
666         struct ifreq atreq;
667         struct atalk_netrange *nr;
668         struct sockaddr_at *sa;
669         struct net_device *dev;
670         struct atalk_iface *atif;
671         int ct;
672         int limit;
673         struct rtentry rtdef;
674         int add_route;
675
676         if (copy_from_user(&atreq, arg, sizeof(atreq)))
677                 return -EFAULT;
678
679         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
680         if (!dev)
681                 return -ENODEV;
682
683         sa = (struct sockaddr_at *)&atreq.ifr_addr;
684         atif = atalk_find_dev(dev);
685
686         switch (cmd) {
687                 case SIOCSIFADDR:
688                         if (!capable(CAP_NET_ADMIN))
689                                 return -EPERM;
690                         if (sa->sat_family != AF_APPLETALK)
691                                 return -EINVAL;
692                         if (dev->type != ARPHRD_ETHER &&
693                             dev->type != ARPHRD_LOOPBACK &&
694                             dev->type != ARPHRD_LOCALTLK &&
695                             dev->type != ARPHRD_PPP)
696                                 return -EPROTONOSUPPORT;
697
698                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
699                         add_route = 1;
700
701                         /*
702                          * if this is a point-to-point iface, and we already
703                          * have an iface for this AppleTalk address, then we
704                          * should not add a route
705                          */
706                         if ((dev->flags & IFF_POINTOPOINT) &&
707                             atalk_find_interface(sa->sat_addr.s_net,
708                                                  sa->sat_addr.s_node)) {
709                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
710                                                   "interface added with "
711                                                   "existing address\n");
712                                 add_route = 0;
713                         }
714
715                         /*
716                          * Phase 1 is fine on LocalTalk but we don't do
717                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
718                          */
719                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
720                                 return -EPROTONOSUPPORT;
721                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
722                             sa->sat_addr.s_node == 254)
723                                 return -EINVAL;
724                         if (atif) {
725                                 /* Already setting address */
726                                 if (atif->status & ATIF_PROBE)
727                                         return -EBUSY;
728
729                                 atif->address.s_net  = sa->sat_addr.s_net;
730                                 atif->address.s_node = sa->sat_addr.s_node;
731                                 atrtr_device_down(dev); /* Flush old routes */
732                         } else {
733                                 atif = atif_add_device(dev, &sa->sat_addr);
734                                 if (!atif)
735                                         return -ENOMEM;
736                         }
737                         atif->nets = *nr;
738
739                         /*
740                          * Check if the chosen address is used. If so we
741                          * error and atalkd will try another.
742                          */
743
744                         if (!(dev->flags & IFF_LOOPBACK) &&
745                             !(dev->flags & IFF_POINTOPOINT) &&
746                             atif_probe_device(atif) < 0) {
747                                 atif_drop_device(dev);
748                                 return -EADDRINUSE;
749                         }
750
751                         /* Hey it worked - add the direct routes */
752                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
753                         sa->sat_family = AF_APPLETALK;
754                         sa->sat_addr.s_net  = atif->address.s_net;
755                         sa->sat_addr.s_node = atif->address.s_node;
756                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
757                         rtdef.rt_flags = RTF_UP;
758                         sa->sat_family = AF_APPLETALK;
759                         sa->sat_addr.s_node = ATADDR_ANYNODE;
760                         if (dev->flags & IFF_LOOPBACK ||
761                             dev->flags & IFF_POINTOPOINT)
762                                 rtdef.rt_flags |= RTF_HOST;
763
764                         /* Routerless initial state */
765                         if (nr->nr_firstnet == htons(0) &&
766                             nr->nr_lastnet == htons(0xFFFE)) {
767                                 sa->sat_addr.s_net = atif->address.s_net;
768                                 atrtr_create(&rtdef, dev);
769                                 atrtr_set_default(dev);
770                         } else {
771                                 limit = ntohs(nr->nr_lastnet);
772                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
773                                         printk(KERN_WARNING "Too many routes/"
774                                                             "iface.\n");
775                                         return -EINVAL;
776                                 }
777                                 if (add_route)
778                                         for (ct = ntohs(nr->nr_firstnet);
779                                              ct <= limit; ct++) {
780                                                 sa->sat_addr.s_net = htons(ct);
781                                                 atrtr_create(&rtdef, dev);
782                                         }
783                         }
784                         dev_mc_add(dev, aarp_mcast, 6, 1);
785                         return 0;
786
787                 case SIOCGIFADDR:
788                         if (!atif)
789                                 return -EADDRNOTAVAIL;
790
791                         sa->sat_family = AF_APPLETALK;
792                         sa->sat_addr = atif->address;
793                         break;
794
795                 case SIOCGIFBRDADDR:
796                         if (!atif)
797                                 return -EADDRNOTAVAIL;
798
799                         sa->sat_family = AF_APPLETALK;
800                         sa->sat_addr.s_net = atif->address.s_net;
801                         sa->sat_addr.s_node = ATADDR_BCAST;
802                         break;
803
804                 case SIOCATALKDIFADDR:
805                 case SIOCDIFADDR:
806                         if (!capable(CAP_NET_ADMIN))
807                                 return -EPERM;
808                         if (sa->sat_family != AF_APPLETALK)
809                                 return -EINVAL;
810                         atalk_dev_down(dev);
811                         break;
812
813                 case SIOCSARP:
814                         if (!capable(CAP_NET_ADMIN))
815                                 return -EPERM;
816                         if (sa->sat_family != AF_APPLETALK)
817                                 return -EINVAL;
818                         if (!atif)
819                                 return -EADDRNOTAVAIL;
820
821                         /*
822                          * for now, we only support proxy AARP on ELAP;
823                          * we should be able to do it for LocalTalk, too.
824                          */
825                         if (dev->type != ARPHRD_ETHER)
826                                 return -EPROTONOSUPPORT;
827
828                         /*
829                          * atif points to the current interface on this network;
830                          * we aren't concerned about its current status (at
831                          * least for now), but it has all the settings about
832                          * the network we're going to probe. Consequently, it
833                          * must exist.
834                          */
835                         if (!atif)
836                                 return -EADDRNOTAVAIL;
837
838                         nr = (struct atalk_netrange *)&(atif->nets);
839                         /*
840                          * Phase 1 is fine on Localtalk but we don't do
841                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
842                          */
843                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
844                                 return -EPROTONOSUPPORT;
845
846                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
847                             sa->sat_addr.s_node == 254)
848                                 return -EINVAL;
849
850                         /*
851                          * Check if the chosen address is used. If so we
852                          * error and ATCP will try another.
853                          */
854                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
855                                 return -EADDRINUSE;
856
857                         /*
858                          * We now have an address on the local network, and
859                          * the AARP code will defend it for us until we take it
860                          * down. We don't set up any routes right now, because
861                          * ATCP will install them manually via SIOCADDRT.
862                          */
863                         break;
864
865                 case SIOCDARP:
866                         if (!capable(CAP_NET_ADMIN))
867                                 return -EPERM;
868                         if (sa->sat_family != AF_APPLETALK)
869                                 return -EINVAL;
870                         if (!atif)
871                                 return -EADDRNOTAVAIL;
872
873                         /* give to aarp module to remove proxy entry */
874                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
875                         return 0;
876         }
877
878         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
879 }
880
881 /* Routing ioctl() calls */
882 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
883 {
884         struct rtentry rt;
885
886         if (copy_from_user(&rt, arg, sizeof(rt)))
887                 return -EFAULT;
888
889         switch (cmd) {
890                 case SIOCDELRT:
891                         if (rt.rt_dst.sa_family != AF_APPLETALK)
892                                 return -EINVAL;
893                         return atrtr_delete(&((struct sockaddr_at *)
894                                                 &rt.rt_dst)->sat_addr);
895
896                 case SIOCADDRT: {
897                         struct net_device *dev = NULL;
898                         if (rt.rt_dev) {
899                                 char name[IFNAMSIZ];
900                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
901                                         return -EFAULT;
902                                 name[IFNAMSIZ-1] = '\0';
903                                 dev = __dev_get_by_name(&init_net, name);
904                                 if (!dev)
905                                         return -ENODEV;
906                         }
907                         return atrtr_create(&rt, dev);
908                 }
909         }
910         return -EINVAL;
911 }
912
913 /**************************************************************************\
914 *                                                                          *
915 * Handling for system calls applied via the various interfaces to an       *
916 * AppleTalk socket object.                                                 *
917 *                                                                          *
918 \**************************************************************************/
919
920 /*
921  * Checksum: This is 'optional'. It's quite likely also a good
922  * candidate for assembler hackery 8)
923  */
924 static unsigned long atalk_sum_partial(const unsigned char *data,
925                                        int len, unsigned long sum)
926 {
927         /* This ought to be unwrapped neatly. I'll trust gcc for now */
928         while (len--) {
929                 sum += *data;
930                 sum <<= 1;
931                 if (sum & 0x10000) {
932                         sum++;
933                         sum &= 0xffff;
934                 }
935                 data++;
936         }
937         return sum;
938 }
939
940 /*  Checksum skb data --  similar to skb_checksum  */
941 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
942                                    int len, unsigned long sum)
943 {
944         int start = skb_headlen(skb);
945         int i, copy;
946
947         /* checksum stuff in header space */
948         if ( (copy = start - offset) > 0) {
949                 if (copy > len)
950                         copy = len;
951                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
952                 if ( (len -= copy) == 0)
953                         return sum;
954
955                 offset += copy;
956         }
957
958         /* checksum stuff in frags */
959         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
960                 int end;
961
962                 WARN_ON(start > offset + len);
963
964                 end = start + skb_shinfo(skb)->frags[i].size;
965                 if ((copy = end - offset) > 0) {
966                         u8 *vaddr;
967                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
968
969                         if (copy > len)
970                                 copy = len;
971                         vaddr = kmap_skb_frag(frag);
972                         sum = atalk_sum_partial(vaddr + frag->page_offset +
973                                                   offset - start, copy, sum);
974                         kunmap_skb_frag(vaddr);
975
976                         if (!(len -= copy))
977                                 return sum;
978                         offset += copy;
979                 }
980                 start = end;
981         }
982
983         if (skb_shinfo(skb)->frag_list) {
984                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
985
986                 for (; list; list = list->next) {
987                         int end;
988
989                         WARN_ON(start > offset + len);
990
991                         end = start + list->len;
992                         if ((copy = end - offset) > 0) {
993                                 if (copy > len)
994                                         copy = len;
995                                 sum = atalk_sum_skb(list, offset - start,
996                                                     copy, sum);
997                                 if ((len -= copy) == 0)
998                                         return sum;
999                                 offset += copy;
1000                         }
1001                         start = end;
1002                 }
1003         }
1004
1005         BUG_ON(len > 0);
1006
1007         return sum;
1008 }
1009
1010 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1011 {
1012         unsigned long sum;
1013
1014         /* skip header 4 bytes */
1015         sum = atalk_sum_skb(skb, 4, len-4, 0);
1016
1017         /* Use 0xFFFF for 0. 0 itself means none */
1018         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1019 }
1020
1021 static struct proto ddp_proto = {
1022         .name     = "DDP",
1023         .owner    = THIS_MODULE,
1024         .obj_size = sizeof(struct atalk_sock),
1025 };
1026
1027 /*
1028  * Create a socket. Initialise the socket, blank the addresses
1029  * set the state.
1030  */
1031 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1032 {
1033         struct sock *sk;
1034         int rc = -ESOCKTNOSUPPORT;
1035
1036         if (net != &init_net)
1037                 return -EAFNOSUPPORT;
1038
1039         /*
1040          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1041          * and gives you the full ELAP frame. Should be handy for CAP 8)
1042          */
1043         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1044                 goto out;
1045         rc = -ENOMEM;
1046         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1047         if (!sk)
1048                 goto out;
1049         rc = 0;
1050         sock->ops = &atalk_dgram_ops;
1051         sock_init_data(sock, sk);
1052
1053         /* Checksums on by default */
1054         sock_set_flag(sk, SOCK_ZAPPED);
1055 out:
1056         return rc;
1057 }
1058
1059 /* Free a socket. No work needed */
1060 static int atalk_release(struct socket *sock)
1061 {
1062         struct sock *sk = sock->sk;
1063
1064         if (sk) {
1065                 sock_orphan(sk);
1066                 sock->sk = NULL;
1067                 atalk_destroy_socket(sk);
1068         }
1069         return 0;
1070 }
1071
1072 /**
1073  * atalk_pick_and_bind_port - Pick a source port when one is not given
1074  * @sk - socket to insert into the tables
1075  * @sat - address to search for
1076  *
1077  * Pick a source port when one is not given. If we can find a suitable free
1078  * one, we insert the socket into the tables using it.
1079  *
1080  * This whole operation must be atomic.
1081  */
1082 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1083 {
1084         int retval;
1085
1086         write_lock_bh(&atalk_sockets_lock);
1087
1088         for (sat->sat_port = ATPORT_RESERVED;
1089              sat->sat_port < ATPORT_LAST;
1090              sat->sat_port++) {
1091                 struct sock *s;
1092                 struct hlist_node *node;
1093
1094                 sk_for_each(s, node, &atalk_sockets) {
1095                         struct atalk_sock *at = at_sk(s);
1096
1097                         if (at->src_net == sat->sat_addr.s_net &&
1098                             at->src_node == sat->sat_addr.s_node &&
1099                             at->src_port == sat->sat_port)
1100                                 goto try_next_port;
1101                 }
1102
1103                 /* Wheee, it's free, assign and insert. */
1104                 __atalk_insert_socket(sk);
1105                 at_sk(sk)->src_port = sat->sat_port;
1106                 retval = 0;
1107                 goto out;
1108
1109 try_next_port:;
1110         }
1111
1112         retval = -EBUSY;
1113 out:
1114         write_unlock_bh(&atalk_sockets_lock);
1115         return retval;
1116 }
1117
1118 static int atalk_autobind(struct sock *sk)
1119 {
1120         struct atalk_sock *at = at_sk(sk);
1121         struct sockaddr_at sat;
1122         struct atalk_addr *ap = atalk_find_primary();
1123         int n = -EADDRNOTAVAIL;
1124
1125         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1126                 goto out;
1127
1128         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1129         at->src_node = sat.sat_addr.s_node = ap->s_node;
1130
1131         n = atalk_pick_and_bind_port(sk, &sat);
1132         if (!n)
1133                 sock_reset_flag(sk, SOCK_ZAPPED);
1134 out:
1135         return n;
1136 }
1137
1138 /* Set the address 'our end' of the connection */
1139 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1140 {
1141         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1142         struct sock *sk = sock->sk;
1143         struct atalk_sock *at = at_sk(sk);
1144
1145         if (!sock_flag(sk, SOCK_ZAPPED) ||
1146             addr_len != sizeof(struct sockaddr_at))
1147                 return -EINVAL;
1148
1149         if (addr->sat_family != AF_APPLETALK)
1150                 return -EAFNOSUPPORT;
1151
1152         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1153                 struct atalk_addr *ap = atalk_find_primary();
1154
1155                 if (!ap)
1156                         return -EADDRNOTAVAIL;
1157
1158                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1159                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1160         } else {
1161                 if (!atalk_find_interface(addr->sat_addr.s_net,
1162                                           addr->sat_addr.s_node))
1163                         return -EADDRNOTAVAIL;
1164
1165                 at->src_net  = addr->sat_addr.s_net;
1166                 at->src_node = addr->sat_addr.s_node;
1167         }
1168
1169         if (addr->sat_port == ATADDR_ANYPORT) {
1170                 int n = atalk_pick_and_bind_port(sk, addr);
1171
1172                 if (n < 0)
1173                         return n;
1174         } else {
1175                 at->src_port = addr->sat_port;
1176
1177                 if (atalk_find_or_insert_socket(sk, addr))
1178                         return -EADDRINUSE;
1179         }
1180
1181         sock_reset_flag(sk, SOCK_ZAPPED);
1182         return 0;
1183 }
1184
1185 /* Set the address we talk to */
1186 static 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
1193         sk->sk_state   = TCP_CLOSE;
1194         sock->state = SS_UNCONNECTED;
1195
1196         if (addr_len != sizeof(*addr))
1197                 return -EINVAL;
1198
1199         addr = (struct sockaddr_at *)uaddr;
1200
1201         if (addr->sat_family != AF_APPLETALK)
1202                 return -EAFNOSUPPORT;
1203
1204         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1205             !sock_flag(sk, SOCK_BROADCAST)) {
1206 #if 1
1207                 printk(KERN_WARNING "%s is broken and did not set "
1208                                     "SO_BROADCAST. It will break when 2.2 is "
1209                                     "released.\n",
1210                         current->comm);
1211 #else
1212                 return -EACCES;
1213 #endif
1214         }
1215
1216         if (sock_flag(sk, SOCK_ZAPPED))
1217                 if (atalk_autobind(sk) < 0)
1218                         return -EBUSY;
1219
1220         if (!atrtr_get_dev(&addr->sat_addr))
1221                 return -ENETUNREACH;
1222
1223         at->dest_port = addr->sat_port;
1224         at->dest_net  = addr->sat_addr.s_net;
1225         at->dest_node = addr->sat_addr.s_node;
1226
1227         sock->state  = SS_CONNECTED;
1228         sk->sk_state = TCP_ESTABLISHED;
1229         return 0;
1230 }
1231
1232 /*
1233  * Find the name of an AppleTalk socket. Just copy the right
1234  * fields into the sockaddr.
1235  */
1236 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1237                          int *uaddr_len, int peer)
1238 {
1239         struct sockaddr_at sat;
1240         struct sock *sk = sock->sk;
1241         struct atalk_sock *at = at_sk(sk);
1242
1243         if (sock_flag(sk, SOCK_ZAPPED))
1244                 if (atalk_autobind(sk) < 0)
1245                         return -ENOBUFS;
1246
1247         *uaddr_len = sizeof(struct sockaddr_at);
1248
1249         if (peer) {
1250                 if (sk->sk_state != TCP_ESTABLISHED)
1251                         return -ENOTCONN;
1252
1253                 sat.sat_addr.s_net  = at->dest_net;
1254                 sat.sat_addr.s_node = at->dest_node;
1255                 sat.sat_port        = at->dest_port;
1256         } else {
1257                 sat.sat_addr.s_net  = at->src_net;
1258                 sat.sat_addr.s_node = at->src_node;
1259                 sat.sat_port        = at->src_port;
1260         }
1261
1262         sat.sat_family = AF_APPLETALK;
1263         memcpy(uaddr, &sat, sizeof(sat));
1264         return 0;
1265 }
1266
1267 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1268 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1269 {
1270         return skb->data[12] == 22;
1271 }
1272
1273 static int handle_ip_over_ddp(struct sk_buff *skb)
1274 {
1275         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1276         struct net_device_stats *stats;
1277
1278         /* This needs to be able to handle ipddp"N" devices */
1279         if (!dev)
1280                 return -ENODEV;
1281
1282         skb->protocol = htons(ETH_P_IP);
1283         skb_pull(skb, 13);
1284         skb->dev   = dev;
1285         skb_reset_transport_header(skb);
1286
1287         stats = dev->priv;
1288         stats->rx_packets++;
1289         stats->rx_bytes += skb->len + 13;
1290         netif_rx(skb);  /* Send the SKB up to a higher place. */
1291         return 0;
1292 }
1293 #else
1294 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1295 #define is_ip_over_ddp(skb) 0
1296 #define handle_ip_over_ddp(skb) 0
1297 #endif
1298
1299 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1300                                struct ddpehdr *ddp, __u16 len_hops,
1301                                int origlen)
1302 {
1303         struct atalk_route *rt;
1304         struct atalk_addr ta;
1305
1306         /*
1307          * Don't route multicast, etc., packets, or packets sent to "this
1308          * network"
1309          */
1310         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1311                 /*
1312                  * FIXME:
1313                  *
1314                  * Can it ever happen that a packet is from a PPP iface and
1315                  * needs to be broadcast onto the default network?
1316                  */
1317                 if (dev->type == ARPHRD_PPP)
1318                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1319                                           "packet received from PPP iface\n");
1320                 goto free_it;
1321         }
1322
1323         ta.s_net  = ddp->deh_dnet;
1324         ta.s_node = ddp->deh_dnode;
1325
1326         /* Route the packet */
1327         rt = atrtr_find(&ta);
1328         /* increment hops count */
1329         len_hops += 1 << 10;
1330         if (!rt || !(len_hops & (15 << 10)))
1331                 goto free_it;
1332
1333         /* FIXME: use skb->cb to be able to use shared skbs */
1334
1335         /*
1336          * Route goes through another gateway, so set the target to the
1337          * gateway instead.
1338          */
1339
1340         if (rt->flags & RTF_GATEWAY) {
1341                 ta.s_net  = rt->gateway.s_net;
1342                 ta.s_node = rt->gateway.s_node;
1343         }
1344
1345         /* Fix up skb->len field */
1346         skb_trim(skb, min_t(unsigned int, origlen,
1347                             (rt->dev->hard_header_len +
1348                              ddp_dl->header_length + (len_hops & 1023))));
1349
1350         /* FIXME: use skb->cb to be able to use shared skbs */
1351         ddp->deh_len_hops = htons(len_hops);
1352
1353         /*
1354          * Send the buffer onwards
1355          *
1356          * Now we must always be careful. If it's come from LocalTalk to
1357          * EtherTalk it might not fit
1358          *
1359          * Order matters here: If a packet has to be copied to make a new
1360          * headroom (rare hopefully) then it won't need unsharing.
1361          *
1362          * Note. ddp-> becomes invalid at the realloc.
1363          */
1364         if (skb_headroom(skb) < 22) {
1365                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1366                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1367                 kfree_skb(skb);
1368                 if (!nskb)
1369                         goto out;
1370                 skb = nskb;
1371         } else
1372                 skb = skb_unshare(skb, GFP_ATOMIC);
1373
1374         /*
1375          * If the buffer didn't vanish into the lack of space bitbucket we can
1376          * send it.
1377          */
1378         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1379                 goto free_it;
1380 out:
1381         return;
1382 free_it:
1383         kfree_skb(skb);
1384 }
1385
1386 /**
1387  *      atalk_rcv - Receive a packet (in skb) from device dev
1388  *      @skb - packet received
1389  *      @dev - network device where the packet comes from
1390  *      @pt - packet type
1391  *
1392  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1393  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1394  *      is the DDP header, skb->len is the DDP length. The physical headers
1395  *      have been extracted. PPP should probably pass frames marked as for this
1396  *      layer.  [ie ARPHRD_ETHERTALK]
1397  */
1398 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1399                      struct packet_type *pt, struct net_device *orig_dev)
1400 {
1401         struct ddpehdr *ddp;
1402         struct sock *sock;
1403         struct atalk_iface *atif;
1404         struct sockaddr_at tosat;
1405         int origlen;
1406         __u16 len_hops;
1407
1408         if (!net_eq(dev_net(dev), &init_net))
1409                 goto freeit;
1410
1411         /* Don't mangle buffer if shared */
1412         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1413                 goto out;
1414
1415         /* Size check and make sure header is contiguous */
1416         if (!pskb_may_pull(skb, sizeof(*ddp)))
1417                 goto freeit;
1418
1419         ddp = ddp_hdr(skb);
1420
1421         len_hops = ntohs(ddp->deh_len_hops);
1422
1423         /* Trim buffer in case of stray trailing data */
1424         origlen = skb->len;
1425         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1426
1427         /*
1428          * Size check to see if ddp->deh_len was crap
1429          * (Otherwise we'll detonate most spectacularly
1430          * in the middle of atalk_checksum() or recvmsg()).
1431          */
1432         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1433                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1434                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1435                 goto freeit;
1436         }
1437
1438         /*
1439          * Any checksums. Note we don't do htons() on this == is assumed to be
1440          * valid for net byte orders all over the networking code...
1441          */
1442         if (ddp->deh_sum &&
1443             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1444                 /* Not a valid AppleTalk frame - dustbin time */
1445                 goto freeit;
1446
1447         /* Check the packet is aimed at us */
1448         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1449                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1450         else
1451                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1452
1453         if (!atif) {
1454                 /* Not ours, so we route the packet via the correct
1455                  * AppleTalk iface
1456                  */
1457                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1458                 goto out;
1459         }
1460
1461         /* if IP over DDP is not selected this code will be optimized out */
1462         if (is_ip_over_ddp(skb))
1463                 return handle_ip_over_ddp(skb);
1464         /*
1465          * Which socket - atalk_search_socket() looks for a *full match*
1466          * of the <net, node, port> tuple.
1467          */
1468         tosat.sat_addr.s_net  = ddp->deh_dnet;
1469         tosat.sat_addr.s_node = ddp->deh_dnode;
1470         tosat.sat_port        = ddp->deh_dport;
1471
1472         sock = atalk_search_socket(&tosat, atif);
1473         if (!sock) /* But not one of our sockets */
1474                 goto freeit;
1475
1476         /* Queue packet (standard) */
1477         skb->sk = sock;
1478
1479         if (sock_queue_rcv_skb(sock, skb) < 0)
1480                 goto freeit;
1481 out:
1482         return 0;
1483 freeit:
1484         kfree_skb(skb);
1485         goto out;
1486 }
1487
1488 /*
1489  * Receive a LocalTalk frame. We make some demands on the caller here.
1490  * Caller must provide enough headroom on the packet to pull the short
1491  * header and append a long one.
1492  */
1493 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1494                      struct packet_type *pt, struct net_device *orig_dev)
1495 {
1496         if (!net_eq(dev_net(dev), &init_net))
1497                 goto freeit;
1498
1499         /* Expand any short form frames */
1500         if (skb_mac_header(skb)[2] == 1) {
1501                 struct ddpehdr *ddp;
1502                 /* Find our address */
1503                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1504
1505                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1506                         goto freeit;
1507
1508                 /* Don't mangle buffer if shared */
1509                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1510                         return 0;
1511
1512                 /*
1513                  * The push leaves us with a ddephdr not an shdr, and
1514                  * handily the port bytes in the right place preset.
1515                  */
1516                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1517
1518                 /* Now fill in the long header */
1519
1520                 /*
1521                  * These two first. The mac overlays the new source/dest
1522                  * network information so we MUST copy these before
1523                  * we write the network numbers !
1524                  */
1525
1526                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1527                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1528
1529                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1530                 ddp->deh_snet  = ap->s_net;
1531                 ddp->deh_sum   = 0;             /* No checksum */
1532                 /*
1533                  * Not sure about this bit...
1534                  */
1535                 /* Non routable, so force a drop if we slip up later */
1536                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1537         }
1538         skb_reset_transport_header(skb);
1539
1540         return atalk_rcv(skb, dev, pt, orig_dev);
1541 freeit:
1542         kfree_skb(skb);
1543         return 0;
1544 }
1545
1546 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1547                          size_t len)
1548 {
1549         struct sock *sk = sock->sk;
1550         struct atalk_sock *at = at_sk(sk);
1551         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1552         int flags = msg->msg_flags;
1553         int loopback = 0;
1554         struct sockaddr_at local_satalk, gsat;
1555         struct sk_buff *skb;
1556         struct net_device *dev;
1557         struct ddpehdr *ddp;
1558         int size;
1559         struct atalk_route *rt;
1560         int err;
1561
1562         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1563                 return -EINVAL;
1564
1565         if (len > DDP_MAXSZ)
1566                 return -EMSGSIZE;
1567
1568         if (usat) {
1569                 if (sock_flag(sk, SOCK_ZAPPED))
1570                         if (atalk_autobind(sk) < 0)
1571                                 return -EBUSY;
1572
1573                 if (msg->msg_namelen < sizeof(*usat) ||
1574                     usat->sat_family != AF_APPLETALK)
1575                         return -EINVAL;
1576
1577                 /* netatalk doesn't implement this check */
1578                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1579                     !sock_flag(sk, SOCK_BROADCAST)) {
1580                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1581                                          "it will break before 2.2\n");
1582 #if 0
1583                         return -EPERM;
1584 #endif
1585                 }
1586         } else {
1587                 if (sk->sk_state != TCP_ESTABLISHED)
1588                         return -ENOTCONN;
1589                 usat = &local_satalk;
1590                 usat->sat_family      = AF_APPLETALK;
1591                 usat->sat_port        = at->dest_port;
1592                 usat->sat_addr.s_node = at->dest_node;
1593                 usat->sat_addr.s_net  = at->dest_net;
1594         }
1595
1596         /* Build a packet */
1597         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1598
1599         /* For headers */
1600         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1601
1602         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1603                 rt = atrtr_find(&usat->sat_addr);
1604         } else {
1605                 struct atalk_addr at_hint;
1606
1607                 at_hint.s_node = 0;
1608                 at_hint.s_net  = at->src_net;
1609
1610                 rt = atrtr_find(&at_hint);
1611         }
1612         if (!rt)
1613                 return -ENETUNREACH;
1614
1615         dev = rt->dev;
1616
1617         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1618                         sk, size, dev->name);
1619
1620         size += dev->hard_header_len;
1621         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1622         if (!skb)
1623                 return err;
1624
1625         skb->sk = sk;
1626         skb_reserve(skb, ddp_dl->header_length);
1627         skb_reserve(skb, dev->hard_header_len);
1628         skb->dev = dev;
1629
1630         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1631
1632         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1633         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1634         ddp->deh_dnet  = usat->sat_addr.s_net;
1635         ddp->deh_snet  = at->src_net;
1636         ddp->deh_dnode = usat->sat_addr.s_node;
1637         ddp->deh_snode = at->src_node;
1638         ddp->deh_dport = usat->sat_port;
1639         ddp->deh_sport = at->src_port;
1640
1641         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1642
1643         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1644         if (err) {
1645                 kfree_skb(skb);
1646                 return -EFAULT;
1647         }
1648
1649         if (sk->sk_no_check == 1)
1650                 ddp->deh_sum = 0;
1651         else
1652                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1653
1654         /*
1655          * Loopback broadcast packets to non gateway targets (ie routes
1656          * to group we are in)
1657          */
1658         if (ddp->deh_dnode == ATADDR_BCAST &&
1659             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1660                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1661
1662                 if (skb2) {
1663                         loopback = 1;
1664                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1665                         if (aarp_send_ddp(dev, skb2,
1666                                           &usat->sat_addr, NULL) == -1)
1667                                 kfree_skb(skb2);
1668                                 /* else queued/sent above in the aarp queue */
1669                 }
1670         }
1671
1672         if (dev->flags & IFF_LOOPBACK || loopback) {
1673                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1674                 /* loop back */
1675                 skb_orphan(skb);
1676                 if (ddp->deh_dnode == ATADDR_BCAST) {
1677                         struct atalk_addr at_lo;
1678
1679                         at_lo.s_node = 0;
1680                         at_lo.s_net  = 0;
1681
1682                         rt = atrtr_find(&at_lo);
1683                         if (!rt) {
1684                                 kfree_skb(skb);
1685                                 return -ENETUNREACH;
1686                         }
1687                         dev = rt->dev;
1688                         skb->dev = dev;
1689                 }
1690                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1691         } else {
1692                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1693                 if (rt->flags & RTF_GATEWAY) {
1694                     gsat.sat_addr = rt->gateway;
1695                     usat = &gsat;
1696                 }
1697
1698                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1699                         kfree_skb(skb);
1700                 /* else queued/sent above in the aarp queue */
1701         }
1702         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1703
1704         return len;
1705 }
1706
1707 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1708                          size_t size, int flags)
1709 {
1710         struct sock *sk = sock->sk;
1711         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1712         struct ddpehdr *ddp;
1713         int copied = 0;
1714         int offset = 0;
1715         int err = 0;
1716         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1717                                                 flags & MSG_DONTWAIT, &err);
1718         if (!skb)
1719                 return err;
1720
1721         /* FIXME: use skb->cb to be able to use shared skbs */
1722         ddp = ddp_hdr(skb);
1723         copied = ntohs(ddp->deh_len_hops) & 1023;
1724
1725         if (sk->sk_type != SOCK_RAW) {
1726                 offset = sizeof(*ddp);
1727                 copied -= offset;
1728         }
1729
1730         if (copied > size) {
1731                 copied = size;
1732                 msg->msg_flags |= MSG_TRUNC;
1733         }
1734         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1735
1736         if (!err) {
1737                 if (sat) {
1738                         sat->sat_family      = AF_APPLETALK;
1739                         sat->sat_port        = ddp->deh_sport;
1740                         sat->sat_addr.s_node = ddp->deh_snode;
1741                         sat->sat_addr.s_net  = ddp->deh_snet;
1742                 }
1743                 msg->msg_namelen = sizeof(*sat);
1744         }
1745
1746         skb_free_datagram(sk, skb);     /* Free the datagram. */
1747         return err ? : copied;
1748 }
1749
1750
1751 /*
1752  * AppleTalk ioctl calls.
1753  */
1754 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1755 {
1756         int rc = -ENOIOCTLCMD;
1757         struct sock *sk = sock->sk;
1758         void __user *argp = (void __user *)arg;
1759
1760         switch (cmd) {
1761                 /* Protocol layer */
1762                 case TIOCOUTQ: {
1763                         long amount = sk->sk_sndbuf -
1764                                       atomic_read(&sk->sk_wmem_alloc);
1765
1766                         if (amount < 0)
1767                                 amount = 0;
1768                         rc = put_user(amount, (int __user *)argp);
1769                         break;
1770                 }
1771                 case TIOCINQ: {
1772                         /*
1773                          * These two are safe on a single CPU system as only
1774                          * user tasks fiddle here
1775                          */
1776                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1777                         long amount = 0;
1778
1779                         if (skb)
1780                                 amount = skb->len - sizeof(struct ddpehdr);
1781                         rc = put_user(amount, (int __user *)argp);
1782                         break;
1783                 }
1784                 case SIOCGSTAMP:
1785                         rc = sock_get_timestamp(sk, argp);
1786                         break;
1787                 case SIOCGSTAMPNS:
1788                         rc = sock_get_timestampns(sk, argp);
1789                         break;
1790                 /* Routing */
1791                 case SIOCADDRT:
1792                 case SIOCDELRT:
1793                         rc = -EPERM;
1794                         if (capable(CAP_NET_ADMIN))
1795                                 rc = atrtr_ioctl(cmd, argp);
1796                         break;
1797                 /* Interface */
1798                 case SIOCGIFADDR:
1799                 case SIOCSIFADDR:
1800                 case SIOCGIFBRDADDR:
1801                 case SIOCATALKDIFADDR:
1802                 case SIOCDIFADDR:
1803                 case SIOCSARP:          /* proxy AARP */
1804                 case SIOCDARP:          /* proxy AARP */
1805                         rtnl_lock();
1806                         rc = atif_ioctl(cmd, argp);
1807                         rtnl_unlock();
1808                         break;
1809         }
1810
1811         return rc;
1812 }
1813
1814
1815 #ifdef CONFIG_COMPAT
1816 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1817 {
1818         /*
1819          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1820          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1821          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1822          * here so there is no generic SIOCPROTOPRIVATE translation in the
1823          * system.
1824          */
1825         return -ENOIOCTLCMD;
1826 }
1827 #endif
1828
1829
1830 static struct net_proto_family atalk_family_ops = {
1831         .family         = PF_APPLETALK,
1832         .create         = atalk_create,
1833         .owner          = THIS_MODULE,
1834 };
1835
1836 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1837         .family         = PF_APPLETALK,
1838         .owner          = THIS_MODULE,
1839         .release        = atalk_release,
1840         .bind           = atalk_bind,
1841         .connect        = atalk_connect,
1842         .socketpair     = sock_no_socketpair,
1843         .accept         = sock_no_accept,
1844         .getname        = atalk_getname,
1845         .poll           = datagram_poll,
1846         .ioctl          = atalk_ioctl,
1847 #ifdef CONFIG_COMPAT
1848         .compat_ioctl   = atalk_compat_ioctl,
1849 #endif
1850         .listen         = sock_no_listen,
1851         .shutdown       = sock_no_shutdown,
1852         .setsockopt     = sock_no_setsockopt,
1853         .getsockopt     = sock_no_getsockopt,
1854         .sendmsg        = atalk_sendmsg,
1855         .recvmsg        = atalk_recvmsg,
1856         .mmap           = sock_no_mmap,
1857         .sendpage       = sock_no_sendpage,
1858 };
1859
1860 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1861
1862 static struct notifier_block ddp_notifier = {
1863         .notifier_call  = ddp_device_event,
1864 };
1865
1866 static struct packet_type ltalk_packet_type = {
1867         .type           = __constant_htons(ETH_P_LOCALTALK),
1868         .func           = ltalk_rcv,
1869 };
1870
1871 static struct packet_type ppptalk_packet_type = {
1872         .type           = __constant_htons(ETH_P_PPPTALK),
1873         .func           = atalk_rcv,
1874 };
1875
1876 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1877
1878 /* Export symbols for use by drivers when AppleTalk is a module */
1879 EXPORT_SYMBOL(aarp_send_ddp);
1880 EXPORT_SYMBOL(atrtr_get_dev);
1881 EXPORT_SYMBOL(atalk_find_dev_addr);
1882
1883 static char atalk_err_snap[] __initdata =
1884         KERN_CRIT "Unable to register DDP with SNAP.\n";
1885
1886 /* Called by proto.c on kernel start up */
1887 static int __init atalk_init(void)
1888 {
1889         int rc = proto_register(&ddp_proto, 0);
1890
1891         if (rc != 0)
1892                 goto out;
1893
1894         (void)sock_register(&atalk_family_ops);
1895         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1896         if (!ddp_dl)
1897                 printk(atalk_err_snap);
1898
1899         dev_add_pack(&ltalk_packet_type);
1900         dev_add_pack(&ppptalk_packet_type);
1901
1902         register_netdevice_notifier(&ddp_notifier);
1903         aarp_proto_init();
1904         atalk_proc_init();
1905         atalk_register_sysctl();
1906 out:
1907         return rc;
1908 }
1909 module_init(atalk_init);
1910
1911 /*
1912  * No explicit module reference count manipulation is needed in the
1913  * protocol. Socket layer sets module reference count for us
1914  * and interfaces reference counting is done
1915  * by the network device layer.
1916  *
1917  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1918  * sockets be closed from user space.
1919  */
1920 static void __exit atalk_exit(void)
1921 {
1922 #ifdef CONFIG_SYSCTL
1923         atalk_unregister_sysctl();
1924 #endif /* CONFIG_SYSCTL */
1925         atalk_proc_exit();
1926         aarp_cleanup_module();  /* General aarp clean-up. */
1927         unregister_netdevice_notifier(&ddp_notifier);
1928         dev_remove_pack(&ltalk_packet_type);
1929         dev_remove_pack(&ppptalk_packet_type);
1930         unregister_snap_client(ddp_dl);
1931         sock_unregister(PF_APPLETALK);
1932         proto_unregister(&ddp_proto);
1933 }
1934 module_exit(atalk_exit);
1935
1936 MODULE_LICENSE("GPL");
1937 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1938 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1939 MODULE_ALIAS_NETPROTO(PF_APPLETALK);