Linux-2.6.12-rc2
[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/config.h>
55 #include <linux/module.h>
56 #include <linux/tcp.h>
57 #include <linux/if_arp.h>
58 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
59 #include <net/datalink.h>
60 #include <net/psnap.h>
61 #include <net/sock.h>
62 #include <net/route.h>
63 #include <linux/atalk.h>
64
65 struct datalink_proto *ddp_dl, *aarp_dl;
66 static struct proto_ops atalk_dgram_ops;
67
68 /**************************************************************************\
69 *                                                                          *
70 * Handlers for the socket list.                                            *
71 *                                                                          *
72 \**************************************************************************/
73
74 HLIST_HEAD(atalk_sockets);
75 DEFINE_RWLOCK(atalk_sockets_lock);
76
77 static inline void __atalk_insert_socket(struct sock *sk)
78 {
79         sk_add_node(sk, &atalk_sockets);
80 }
81
82 static inline void atalk_remove_socket(struct sock *sk)
83 {
84         write_lock_bh(&atalk_sockets_lock);
85         sk_del_node_init(sk);
86         write_unlock_bh(&atalk_sockets_lock);
87 }
88
89 static struct sock *atalk_search_socket(struct sockaddr_at *to,
90                                         struct atalk_iface *atif)
91 {
92         struct sock *s;
93         struct hlist_node *node;
94
95         read_lock_bh(&atalk_sockets_lock);
96         sk_for_each(s, node, &atalk_sockets) {
97                 struct atalk_sock *at = at_sk(s);
98
99                 if (to->sat_port != at->src_port)
100                         continue;
101
102                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
103                     to->sat_addr.s_node == ATADDR_BCAST &&
104                     at->src_net == atif->address.s_net)
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 = kmalloc(sizeof(*iface), GFP_KERNEL);
232
233         if (!iface)
234                 goto out;
235
236         memset(iface, 0, sizeof(*iface));
237         dev_hold(dev);
238         iface->dev = dev;
239         dev->atalk_ptr = iface;
240         iface->address = *sa;
241         iface->status = 0;
242
243         write_lock_bh(&atalk_interfaces_lock);
244         iface->next = atalk_interfaces;
245         atalk_interfaces = iface;
246         write_unlock_bh(&atalk_interfaces_lock);
247 out:
248         return iface;
249 }
250
251 /* Perform phase 2 AARP probing on our tentative address */
252 static int atif_probe_device(struct atalk_iface *atif)
253 {
254         int netrange = ntohs(atif->nets.nr_lastnet) -
255                         ntohs(atif->nets.nr_firstnet) + 1;
256         int probe_net = ntohs(atif->address.s_net);
257         int probe_node = atif->address.s_node;
258         int netct, nodect;
259
260         /* Offset the network we start probing with */
261         if (probe_net == ATADDR_ANYNET) {
262                 probe_net = ntohs(atif->nets.nr_firstnet);
263                 if (netrange)
264                         probe_net += jiffies % netrange;
265         }
266         if (probe_node == ATADDR_ANYNODE)
267                 probe_node = jiffies & 0xFF;
268
269         /* Scan the networks */
270         atif->status |= ATIF_PROBE;
271         for (netct = 0; netct <= netrange; netct++) {
272                 /* Sweep the available nodes from a given start */
273                 atif->address.s_net = htons(probe_net);
274                 for (nodect = 0; nodect < 256; nodect++) {
275                         atif->address.s_node = (nodect + probe_node) & 0xFF;
276                         if (atif->address.s_node > 0 &&
277                             atif->address.s_node < 254) {
278                                 /* Probe a proposed address */
279                                 aarp_probe_network(atif);
280
281                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
282                                         atif->status &= ~ATIF_PROBE;
283                                         return 0;
284                                 }
285                         }
286                         atif->status &= ~ATIF_PROBE_FAIL;
287                 }
288                 probe_net++;
289                 if (probe_net > ntohs(atif->nets.nr_lastnet))
290                         probe_net = ntohs(atif->nets.nr_firstnet);
291         }
292         atif->status &= ~ATIF_PROBE;
293
294         return -EADDRINUSE;     /* Network is full... */
295 }
296
297
298 /* Perform AARP probing for a proxy address */
299 static int atif_proxy_probe_device(struct atalk_iface *atif,
300                                    struct atalk_addr* proxy_addr)
301 {
302         int netrange = ntohs(atif->nets.nr_lastnet) -
303                         ntohs(atif->nets.nr_firstnet) + 1;
304         /* we probe the interface's network */
305         int probe_net = ntohs(atif->address.s_net);
306         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
307         int netct, nodect;
308
309         /* Offset the network we start probing with */
310         if (probe_net == ATADDR_ANYNET) {
311                 probe_net = ntohs(atif->nets.nr_firstnet);
312                 if (netrange)
313                         probe_net += jiffies % netrange;
314         }
315
316         if (probe_node == ATADDR_ANYNODE)
317                 probe_node = jiffies & 0xFF;
318                 
319         /* Scan the networks */
320         for (netct = 0; netct <= netrange; netct++) {
321                 /* Sweep the available nodes from a given start */
322                 proxy_addr->s_net = htons(probe_net);
323                 for (nodect = 0; nodect < 256; nodect++) {
324                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
325                         if (proxy_addr->s_node > 0 &&
326                             proxy_addr->s_node < 254) {
327                                 /* Tell AARP to probe a proposed address */
328                                 int ret = aarp_proxy_probe_network(atif,
329                                                                     proxy_addr);
330
331                                 if (ret != -EADDRINUSE)
332                                         return ret;
333                         }
334                 }
335                 probe_net++;
336                 if (probe_net > ntohs(atif->nets.nr_lastnet))
337                         probe_net = ntohs(atif->nets.nr_firstnet);
338         }
339
340         return -EADDRINUSE;     /* Network is full... */
341 }
342
343
344 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
345 {
346         struct atalk_iface *iface = dev->atalk_ptr;
347         return iface ? &iface->address : NULL;
348 }
349
350 static struct atalk_addr *atalk_find_primary(void)
351 {
352         struct atalk_iface *fiface = NULL;
353         struct atalk_addr *retval;
354         struct atalk_iface *iface;
355
356         /*
357          * Return a point-to-point interface only if
358          * there is no non-ptp interface available.
359          */
360         read_lock_bh(&atalk_interfaces_lock);
361         for (iface = atalk_interfaces; iface; iface = iface->next) {
362                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
363                         fiface = iface;
364                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
365                         retval = &iface->address;
366                         goto out;
367                 }
368         }
369
370         if (fiface)
371                 retval = &fiface->address;
372         else if (atalk_interfaces)
373                 retval = &atalk_interfaces->address;
374         else
375                 retval = NULL;
376 out:
377         read_unlock_bh(&atalk_interfaces_lock);
378         return retval;
379 }
380
381 /*
382  * Find a match for 'any network' - ie any of our interfaces with that
383  * node number will do just nicely.
384  */
385 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
386 {
387         struct atalk_iface *iface = dev->atalk_ptr;
388
389         if (!iface || iface->status & ATIF_PROBE)
390                 goto out_err;
391
392         if (node != ATADDR_BCAST &&
393             iface->address.s_node != node &&
394             node != ATADDR_ANYNODE)
395                 goto out_err;
396 out:
397         return iface;
398 out_err:
399         iface = NULL;
400         goto out;
401 }
402
403 /* Find a match for a specific network:node pair */
404 static struct atalk_iface *atalk_find_interface(int net, int node)
405 {
406         struct atalk_iface *iface;
407
408         read_lock_bh(&atalk_interfaces_lock);
409         for (iface = atalk_interfaces; iface; iface = iface->next) {
410                 if ((node == ATADDR_BCAST ||
411                      node == ATADDR_ANYNODE ||
412                      iface->address.s_node == node) &&
413                     iface->address.s_net == net &&
414                     !(iface->status & ATIF_PROBE))
415                         break;
416
417                 /* XXXX.0 -- net.0 returns the iface associated with net */
418                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
419                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
420                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
421                         break;
422         }
423         read_unlock_bh(&atalk_interfaces_lock);
424         return iface;
425 }
426
427
428 /*
429  * Find a route for an AppleTalk packet. This ought to get cached in
430  * the socket (later on...). We know about host routes and the fact
431  * that a route must be direct to broadcast.
432  */
433 static struct atalk_route *atrtr_find(struct atalk_addr *target)
434 {
435         /*
436          * we must search through all routes unless we find a 
437          * host route, because some host routes might overlap
438          * network routes
439          */
440         struct atalk_route *net_route = NULL;
441         struct atalk_route *r;
442         
443         read_lock_bh(&atalk_routes_lock);
444         for (r = atalk_routes; r; r = r->next) {
445                 if (!(r->flags & RTF_UP))
446                         continue;
447
448                 if (r->target.s_net == target->s_net) {
449                         if (r->flags & RTF_HOST) {
450                                 /*
451                                  * if this host route is for the target,
452                                  * the we're done
453                                  */
454                                 if (r->target.s_node == target->s_node)
455                                         goto out;
456                         } else
457                                 /*
458                                  * this route will work if there isn't a
459                                  * direct host route, so cache it
460                                  */
461                                 net_route = r;
462                 }
463         }
464         
465         /* 
466          * if we found a network route but not a direct host
467          * route, then return it
468          */
469         if (net_route)
470                 r = net_route;
471         else if (atrtr_default.dev)
472                 r = &atrtr_default;
473         else /* No route can be found */
474                 r = NULL;
475 out:
476         read_unlock_bh(&atalk_routes_lock);
477         return r;
478 }
479
480
481 /*
482  * Given an AppleTalk network, find the device to use. This can be
483  * a simple lookup.
484  */
485 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
486 {
487         struct atalk_route *atr = atrtr_find(sa);
488         return atr ? atr->dev : NULL;
489 }
490
491 /* Set up a default router */
492 static void atrtr_set_default(struct net_device *dev)
493 {
494         atrtr_default.dev            = dev;
495         atrtr_default.flags          = RTF_UP;
496         atrtr_default.gateway.s_net  = htons(0);
497         atrtr_default.gateway.s_node = 0;
498 }
499
500 /*
501  * Add a router. Basically make sure it looks valid and stuff the
502  * entry in the list. While it uses netranges we always set them to one
503  * entry to work like netatalk.
504  */
505 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
506 {
507         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
508         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
509         struct atalk_route *rt;
510         struct atalk_iface *iface, *riface;
511         int retval = -EINVAL;
512
513         /*
514          * Fixme: Raise/Lower a routing change semaphore for these
515          * operations.
516          */
517
518         /* Validate the request */
519         if (ta->sat_family != AF_APPLETALK ||
520             (!devhint && ga->sat_family != AF_APPLETALK))
521                 goto out;
522
523         /* Now walk the routing table and make our decisions */
524         write_lock_bh(&atalk_routes_lock);
525         for (rt = atalk_routes; rt; rt = rt->next) {
526                 if (r->rt_flags != rt->flags)
527                         continue;
528
529                 if (ta->sat_addr.s_net == rt->target.s_net) {
530                         if (!(rt->flags & RTF_HOST))
531                                 break;
532                         if (ta->sat_addr.s_node == rt->target.s_node)
533                                 break;
534                 }
535         }
536
537         if (!devhint) {
538                 riface = NULL;
539
540                 read_lock_bh(&atalk_interfaces_lock);
541                 for (iface = atalk_interfaces; iface; iface = iface->next) {
542                         if (!riface &&
543                             ntohs(ga->sat_addr.s_net) >=
544                                         ntohs(iface->nets.nr_firstnet) &&
545                             ntohs(ga->sat_addr.s_net) <=
546                                         ntohs(iface->nets.nr_lastnet))
547                                 riface = iface;
548
549                         if (ga->sat_addr.s_net == iface->address.s_net &&
550                             ga->sat_addr.s_node == iface->address.s_node)
551                                 riface = iface;
552                 }               
553                 read_unlock_bh(&atalk_interfaces_lock);
554
555                 retval = -ENETUNREACH;
556                 if (!riface)
557                         goto out_unlock;
558
559                 devhint = riface->dev;
560         }
561
562         if (!rt) {
563                 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
564
565                 retval = -ENOBUFS;
566                 if (!rt)
567                         goto out_unlock;
568                 memset(rt, 0, sizeof(*rt));
569
570                 rt->next = atalk_routes;
571                 atalk_routes = rt;
572         }
573
574         /* Fill in the routing entry */
575         rt->target  = ta->sat_addr;
576         rt->dev     = devhint;
577         rt->flags   = r->rt_flags;
578         rt->gateway = ga->sat_addr;
579
580         retval = 0;
581 out_unlock:
582         write_unlock_bh(&atalk_routes_lock);
583 out:
584         return retval;
585 }
586
587 /* Delete a route. Find it and discard it */
588 static int atrtr_delete(struct atalk_addr * addr)
589 {
590         struct atalk_route **r = &atalk_routes;
591         int retval = 0;
592         struct atalk_route *tmp;
593
594         write_lock_bh(&atalk_routes_lock);
595         while ((tmp = *r) != NULL) {
596                 if (tmp->target.s_net == addr->s_net &&
597                     (!(tmp->flags&RTF_GATEWAY) ||
598                      tmp->target.s_node == addr->s_node)) {
599                         *r = tmp->next;
600                         dev_put(tmp->dev);
601                         kfree(tmp);
602                         goto out;
603                 }
604                 r = &tmp->next;
605         }
606         retval = -ENOENT;
607 out:
608         write_unlock_bh(&atalk_routes_lock);
609         return retval;
610 }
611
612 /*
613  * Called when a device is downed. Just throw away any routes
614  * via it.
615  */
616 static void atrtr_device_down(struct net_device *dev)
617 {
618         struct atalk_route **r = &atalk_routes;
619         struct atalk_route *tmp;
620
621         write_lock_bh(&atalk_routes_lock);
622         while ((tmp = *r) != NULL) {
623                 if (tmp->dev == dev) {
624                         *r = tmp->next;
625                         dev_put(dev);
626                         kfree(tmp);
627                 } else
628                         r = &tmp->next;
629         }
630         write_unlock_bh(&atalk_routes_lock);
631
632         if (atrtr_default.dev == dev)
633                 atrtr_set_default(NULL);
634 }
635
636 /* Actually down the interface */
637 static inline void atalk_dev_down(struct net_device *dev)
638 {
639         atrtr_device_down(dev); /* Remove all routes for the device */
640         aarp_device_down(dev);  /* Remove AARP entries for the device */
641         atif_drop_device(dev);  /* Remove the device */
642 }
643
644 /*
645  * A device event has occurred. Watch for devices going down and
646  * delete our use of them (iface and route).
647  */
648 static int ddp_device_event(struct notifier_block *this, unsigned long event,
649                             void *ptr)
650 {
651         if (event == NETDEV_DOWN)
652                 /* Discard any use of this */
653                 atalk_dev_down(ptr);
654
655         return NOTIFY_DONE;
656 }
657
658 /* ioctl calls. Shouldn't even need touching */
659 /* Device configuration ioctl calls */
660 static int atif_ioctl(int cmd, void __user *arg)
661 {
662         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
663         struct ifreq atreq;
664         struct atalk_netrange *nr;
665         struct sockaddr_at *sa;
666         struct net_device *dev;
667         struct atalk_iface *atif;
668         int ct;
669         int limit;
670         struct rtentry rtdef;
671         int add_route;
672
673         if (copy_from_user(&atreq, arg, sizeof(atreq)))
674                 return -EFAULT;
675
676         dev = __dev_get_by_name(atreq.ifr_name);
677         if (!dev)
678                 return -ENODEV;
679
680         sa = (struct sockaddr_at *)&atreq.ifr_addr;
681         atif = atalk_find_dev(dev);
682
683         switch (cmd) {
684                 case SIOCSIFADDR:
685                         if (!capable(CAP_NET_ADMIN))
686                                 return -EPERM;
687                         if (sa->sat_family != AF_APPLETALK)
688                                 return -EINVAL;
689                         if (dev->type != ARPHRD_ETHER &&
690                             dev->type != ARPHRD_LOOPBACK &&
691                             dev->type != ARPHRD_LOCALTLK &&
692                             dev->type != ARPHRD_PPP)
693                                 return -EPROTONOSUPPORT;
694
695                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
696                         add_route = 1;
697
698                         /*
699                          * if this is a point-to-point iface, and we already
700                          * have an iface for this AppleTalk address, then we
701                          * should not add a route
702                          */
703                         if ((dev->flags & IFF_POINTOPOINT) &&
704                             atalk_find_interface(sa->sat_addr.s_net,
705                                                  sa->sat_addr.s_node)) {
706                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
707                                                   "interface added with "
708                                                   "existing address\n");
709                                 add_route = 0;
710                         }
711                         
712                         /*
713                          * Phase 1 is fine on LocalTalk but we don't do
714                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
715                          */
716                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
717                                 return -EPROTONOSUPPORT;
718                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
719                             sa->sat_addr.s_node == 254)
720                                 return -EINVAL;
721                         if (atif) {
722                                 /* Already setting address */
723                                 if (atif->status & ATIF_PROBE)
724                                         return -EBUSY;
725
726                                 atif->address.s_net  = sa->sat_addr.s_net;
727                                 atif->address.s_node = sa->sat_addr.s_node;
728                                 atrtr_device_down(dev); /* Flush old routes */
729                         } else {
730                                 atif = atif_add_device(dev, &sa->sat_addr);
731                                 if (!atif)
732                                         return -ENOMEM;
733                         }
734                         atif->nets = *nr;
735
736                         /*
737                          * Check if the chosen address is used. If so we
738                          * error and atalkd will try another.
739                          */
740
741                         if (!(dev->flags & IFF_LOOPBACK) &&
742                             !(dev->flags & IFF_POINTOPOINT) &&
743                             atif_probe_device(atif) < 0) {
744                                 atif_drop_device(dev);
745                                 return -EADDRINUSE;
746                         }
747
748                         /* Hey it worked - add the direct routes */
749                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
750                         sa->sat_family = AF_APPLETALK;
751                         sa->sat_addr.s_net  = atif->address.s_net;
752                         sa->sat_addr.s_node = atif->address.s_node;
753                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
754                         rtdef.rt_flags = RTF_UP;
755                         sa->sat_family = AF_APPLETALK;
756                         sa->sat_addr.s_node = ATADDR_ANYNODE;
757                         if (dev->flags & IFF_LOOPBACK ||
758                             dev->flags & IFF_POINTOPOINT)
759                                 rtdef.rt_flags |= RTF_HOST;
760
761                         /* Routerless initial state */
762                         if (nr->nr_firstnet == htons(0) &&
763                             nr->nr_lastnet == htons(0xFFFE)) {
764                                 sa->sat_addr.s_net = atif->address.s_net;
765                                 atrtr_create(&rtdef, dev);
766                                 atrtr_set_default(dev);
767                         } else {
768                                 limit = ntohs(nr->nr_lastnet);
769                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
770                                         printk(KERN_WARNING "Too many routes/"
771                                                             "iface.\n");
772                                         return -EINVAL;
773                                 }
774                                 if (add_route)
775                                         for (ct = ntohs(nr->nr_firstnet);
776                                              ct <= limit; ct++) {
777                                                 sa->sat_addr.s_net = htons(ct);
778                                                 atrtr_create(&rtdef, dev);
779                                         }
780                         }
781                         dev_mc_add(dev, aarp_mcast, 6, 1);
782                         return 0;
783
784                 case SIOCGIFADDR:
785                         if (!atif)
786                                 return -EADDRNOTAVAIL;
787
788                         sa->sat_family = AF_APPLETALK;
789                         sa->sat_addr = atif->address;
790                         break;
791
792                 case SIOCGIFBRDADDR:
793                         if (!atif)
794                                 return -EADDRNOTAVAIL;
795
796                         sa->sat_family = AF_APPLETALK;
797                         sa->sat_addr.s_net = atif->address.s_net;
798                         sa->sat_addr.s_node = ATADDR_BCAST;
799                         break;
800
801                 case SIOCATALKDIFADDR:
802                 case SIOCDIFADDR:
803                         if (!capable(CAP_NET_ADMIN))
804                                 return -EPERM;
805                         if (sa->sat_family != AF_APPLETALK)
806                                 return -EINVAL;
807                         atalk_dev_down(dev);
808                         break;                  
809
810                 case SIOCSARP:
811                         if (!capable(CAP_NET_ADMIN))
812                                 return -EPERM;
813                         if (sa->sat_family != AF_APPLETALK)
814                                 return -EINVAL;
815                         if (!atif)
816                                 return -EADDRNOTAVAIL;
817
818                         /*
819                          * for now, we only support proxy AARP on ELAP;
820                          * we should be able to do it for LocalTalk, too.
821                          */
822                         if (dev->type != ARPHRD_ETHER)
823                                 return -EPROTONOSUPPORT;
824
825                         /*
826                          * atif points to the current interface on this network;
827                          * we aren't concerned about its current status (at
828                          * least for now), but it has all the settings about
829                          * the network we're going to probe. Consequently, it
830                          * must exist.
831                          */
832                         if (!atif)
833                                 return -EADDRNOTAVAIL;
834
835                         nr = (struct atalk_netrange *)&(atif->nets);
836                         /*
837                          * Phase 1 is fine on Localtalk but we don't do
838                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
839                          */
840                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
841                                 return -EPROTONOSUPPORT;
842
843                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
844                             sa->sat_addr.s_node == 254)
845                                 return -EINVAL;
846
847                         /*
848                          * Check if the chosen address is used. If so we
849                          * error and ATCP will try another.
850                          */
851                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
852                                 return -EADDRINUSE;
853                         
854                         /*
855                          * We now have an address on the local network, and
856                          * the AARP code will defend it for us until we take it
857                          * down. We don't set up any routes right now, because
858                          * ATCP will install them manually via SIOCADDRT.
859                          */
860                         break;
861
862                 case SIOCDARP:
863                         if (!capable(CAP_NET_ADMIN))
864                                 return -EPERM;
865                         if (sa->sat_family != AF_APPLETALK)
866                                 return -EINVAL;
867                         if (!atif)
868                                 return -EADDRNOTAVAIL;
869
870                         /* give to aarp module to remove proxy entry */
871                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
872                         return 0;
873         }
874
875         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
876 }
877
878 /* Routing ioctl() calls */
879 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
880 {
881         struct rtentry rt;
882
883         if (copy_from_user(&rt, arg, sizeof(rt)))
884                 return -EFAULT;
885
886         switch (cmd) {
887                 case SIOCDELRT:
888                         if (rt.rt_dst.sa_family != AF_APPLETALK)
889                                 return -EINVAL;
890                         return atrtr_delete(&((struct sockaddr_at *)
891                                                 &rt.rt_dst)->sat_addr);
892
893                 case SIOCADDRT: {
894                         struct net_device *dev = NULL;
895                         if (rt.rt_dev) {
896                                 char name[IFNAMSIZ];
897                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
898                                         return -EFAULT;
899                                 name[IFNAMSIZ-1] = '\0';
900                                 dev = __dev_get_by_name(name);
901                                 if (!dev)
902                                         return -ENODEV;
903                         }                       
904                         return atrtr_create(&rt, dev);
905                 }
906         }
907         return -EINVAL;
908 }
909
910 /**************************************************************************\
911 *                                                                          *
912 * Handling for system calls applied via the various interfaces to an       *
913 * AppleTalk socket object.                                                 *
914 *                                                                          *
915 \**************************************************************************/
916
917 /*
918  * Checksum: This is 'optional'. It's quite likely also a good
919  * candidate for assembler hackery 8)
920  */
921 static unsigned long atalk_sum_partial(const unsigned char *data, 
922                                        int len, unsigned long sum)
923 {
924         /* This ought to be unwrapped neatly. I'll trust gcc for now */
925         while (len--) {
926                 sum += *data;
927                 sum <<= 1;
928                 if (sum & 0x10000) {
929                         sum++;
930                         sum &= 0xffff;
931                 }
932                 data++;
933         }
934         return sum;
935 }
936
937 /*  Checksum skb data --  similar to skb_checksum  */
938 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
939                                    int len, unsigned long sum)
940 {
941         int start = skb_headlen(skb);
942         int i, copy;
943
944         /* checksum stuff in header space */
945         if ( (copy = start - offset) > 0) {
946                 if (copy > len)
947                         copy = len;
948                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
949                 if ( (len -= copy) == 0) 
950                         return sum;
951
952                 offset += copy;
953         }
954
955         /* checksum stuff in frags */
956         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
957                 int end;
958
959                 BUG_TRAP(start <= offset + len);
960
961                 end = start + skb_shinfo(skb)->frags[i].size;
962                 if ((copy = end - offset) > 0) {
963                         u8 *vaddr;
964                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
965
966                         if (copy > len)
967                                 copy = len;
968                         vaddr = kmap_skb_frag(frag);
969                         sum = atalk_sum_partial(vaddr + frag->page_offset +
970                                                   offset - start, copy, sum);
971                         kunmap_skb_frag(vaddr);
972
973                         if (!(len -= copy))
974                                 return sum;
975                         offset += copy;
976                 }
977                 start = end;
978         }
979
980         if (skb_shinfo(skb)->frag_list) {
981                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
982
983                 for (; list; list = list->next) {
984                         int end;
985
986                         BUG_TRAP(start <= offset + len);
987
988                         end = start + list->len;
989                         if ((copy = end - offset) > 0) {
990                                 if (copy > len)
991                                         copy = len;
992                                 sum = atalk_sum_skb(list, offset - start,
993                                                     copy, sum);
994                                 if ((len -= copy) == 0)
995                                         return sum;
996                                 offset += copy;
997                         }
998                         start = end;
999                 }
1000         }
1001
1002         BUG_ON(len > 0);
1003
1004         return sum;
1005 }
1006
1007 static unsigned short atalk_checksum(const struct sk_buff *skb, int len)
1008 {
1009         unsigned long sum;
1010
1011         /* skip header 4 bytes */
1012         sum = atalk_sum_skb(skb, 4, len-4, 0);
1013
1014         /* Use 0xFFFF for 0. 0 itself means none */
1015         return sum ? htons((unsigned short)sum) : 0xFFFF;
1016 }
1017
1018 static struct proto ddp_proto = {
1019         .name     = "DDP",
1020         .owner    = THIS_MODULE,
1021         .obj_size = sizeof(struct atalk_sock),
1022 };
1023
1024 /*
1025  * Create a socket. Initialise the socket, blank the addresses
1026  * set the state.
1027  */
1028 static int atalk_create(struct socket *sock, int protocol)
1029 {
1030         struct sock *sk;
1031         int rc = -ESOCKTNOSUPPORT;
1032
1033         /*
1034          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1035          * and gives you the full ELAP frame. Should be handy for CAP 8) 
1036          */
1037         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1038                 goto out;
1039         rc = -ENOMEM;
1040         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1041         if (!sk)
1042                 goto out;
1043         rc = 0;
1044         sock->ops = &atalk_dgram_ops;
1045         sock_init_data(sock, sk);
1046
1047         /* Checksums on by default */
1048         sock_set_flag(sk, SOCK_ZAPPED);
1049 out:
1050         return rc;
1051 }
1052
1053 /* Free a socket. No work needed */
1054 static int atalk_release(struct socket *sock)
1055 {
1056         struct sock *sk = sock->sk;
1057
1058         if (sk) {
1059                 sock_orphan(sk);
1060                 sock->sk = NULL;
1061                 atalk_destroy_socket(sk);
1062         }
1063         return 0;
1064 }
1065
1066 /**
1067  * atalk_pick_and_bind_port - Pick a source port when one is not given
1068  * @sk - socket to insert into the tables
1069  * @sat - address to search for
1070  *
1071  * Pick a source port when one is not given. If we can find a suitable free
1072  * one, we insert the socket into the tables using it.
1073  *
1074  * This whole operation must be atomic.
1075  */
1076 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1077 {
1078         int retval;
1079
1080         write_lock_bh(&atalk_sockets_lock);
1081
1082         for (sat->sat_port = ATPORT_RESERVED;
1083              sat->sat_port < ATPORT_LAST;
1084              sat->sat_port++) {
1085                 struct sock *s;
1086                 struct hlist_node *node;
1087
1088                 sk_for_each(s, node, &atalk_sockets) {
1089                         struct atalk_sock *at = at_sk(s);
1090
1091                         if (at->src_net == sat->sat_addr.s_net &&
1092                             at->src_node == sat->sat_addr.s_node &&
1093                             at->src_port == sat->sat_port)
1094                                 goto try_next_port;
1095                 }
1096
1097                 /* Wheee, it's free, assign and insert. */
1098                 __atalk_insert_socket(sk);
1099                 at_sk(sk)->src_port = sat->sat_port;
1100                 retval = 0;
1101                 goto out;
1102
1103 try_next_port:;
1104         }
1105
1106         retval = -EBUSY;
1107 out:
1108         write_unlock_bh(&atalk_sockets_lock);
1109         return retval;
1110 }
1111
1112 static int atalk_autobind(struct sock *sk)
1113 {
1114         struct atalk_sock *at = at_sk(sk);
1115         struct sockaddr_at sat;
1116         struct atalk_addr *ap = atalk_find_primary();
1117         int n = -EADDRNOTAVAIL;
1118
1119         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1120                 goto out;
1121
1122         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1123         at->src_node = sat.sat_addr.s_node = ap->s_node;
1124
1125         n = atalk_pick_and_bind_port(sk, &sat);
1126         if (!n)
1127                 sock_reset_flag(sk, SOCK_ZAPPED);
1128 out:
1129         return n;
1130 }
1131
1132 /* Set the address 'our end' of the connection */
1133 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1134 {
1135         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1136         struct sock *sk = sock->sk;
1137         struct atalk_sock *at = at_sk(sk);
1138
1139         if (!sock_flag(sk, SOCK_ZAPPED) ||
1140             addr_len != sizeof(struct sockaddr_at))
1141                 return -EINVAL;
1142
1143         if (addr->sat_family != AF_APPLETALK)
1144                 return -EAFNOSUPPORT;
1145
1146         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1147                 struct atalk_addr *ap = atalk_find_primary();
1148
1149                 if (!ap)
1150                         return -EADDRNOTAVAIL;
1151
1152                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1153                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1154         } else {
1155                 if (!atalk_find_interface(addr->sat_addr.s_net,
1156                                           addr->sat_addr.s_node))
1157                         return -EADDRNOTAVAIL;
1158
1159                 at->src_net  = addr->sat_addr.s_net;
1160                 at->src_node = addr->sat_addr.s_node;
1161         }
1162
1163         if (addr->sat_port == ATADDR_ANYPORT) {
1164                 int n = atalk_pick_and_bind_port(sk, addr);
1165
1166                 if (n < 0)
1167                         return n;
1168         } else {
1169                 at->src_port = addr->sat_port;
1170
1171                 if (atalk_find_or_insert_socket(sk, addr))
1172                         return -EADDRINUSE;
1173         }
1174
1175         sock_reset_flag(sk, SOCK_ZAPPED);
1176         return 0;
1177 }
1178
1179 /* Set the address we talk to */
1180 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1181                          int addr_len, int flags)
1182 {
1183         struct sock *sk = sock->sk;
1184         struct atalk_sock *at = at_sk(sk);
1185         struct sockaddr_at *addr;
1186
1187         sk->sk_state   = TCP_CLOSE;
1188         sock->state = SS_UNCONNECTED;
1189
1190         if (addr_len != sizeof(*addr))
1191                 return -EINVAL;
1192
1193         addr = (struct sockaddr_at *)uaddr;
1194
1195         if (addr->sat_family != AF_APPLETALK)
1196                 return -EAFNOSUPPORT;
1197
1198         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1199             !sock_flag(sk, SOCK_BROADCAST)) {
1200 #if 1   
1201                 printk(KERN_WARNING "%s is broken and did not set "
1202                                     "SO_BROADCAST. It will break when 2.2 is "
1203                                     "released.\n",
1204                         current->comm);
1205 #else
1206                 return -EACCES;
1207 #endif                  
1208         }
1209
1210         if (sock_flag(sk, SOCK_ZAPPED))
1211                 if (atalk_autobind(sk) < 0)
1212                         return -EBUSY;
1213
1214         if (!atrtr_get_dev(&addr->sat_addr))
1215                 return -ENETUNREACH;
1216
1217         at->dest_port = addr->sat_port;
1218         at->dest_net  = addr->sat_addr.s_net;
1219         at->dest_node = addr->sat_addr.s_node;
1220
1221         sock->state  = SS_CONNECTED;
1222         sk->sk_state = TCP_ESTABLISHED;
1223         return 0;
1224 }
1225
1226 /*
1227  * Find the name of an AppleTalk socket. Just copy the right
1228  * fields into the sockaddr.
1229  */
1230 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1231                          int *uaddr_len, int peer)
1232 {
1233         struct sockaddr_at sat;
1234         struct sock *sk = sock->sk;
1235         struct atalk_sock *at = at_sk(sk);
1236
1237         if (sock_flag(sk, SOCK_ZAPPED))
1238                 if (atalk_autobind(sk) < 0)
1239                         return -ENOBUFS;
1240
1241         *uaddr_len = sizeof(struct sockaddr_at);
1242
1243         if (peer) {
1244                 if (sk->sk_state != TCP_ESTABLISHED)
1245                         return -ENOTCONN;
1246
1247                 sat.sat_addr.s_net  = at->dest_net;
1248                 sat.sat_addr.s_node = at->dest_node;
1249                 sat.sat_port        = at->dest_port;
1250         } else {
1251                 sat.sat_addr.s_net  = at->src_net;
1252                 sat.sat_addr.s_node = at->src_node;
1253                 sat.sat_port        = at->src_port;
1254         }
1255
1256         sat.sat_family = AF_APPLETALK;
1257         memcpy(uaddr, &sat, sizeof(sat));
1258         return 0;
1259 }
1260
1261 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1262 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1263 {
1264         return skb->data[12] == 22;
1265 }
1266
1267 static int handle_ip_over_ddp(struct sk_buff *skb)
1268 {
1269         struct net_device *dev = __dev_get_by_name("ipddp0");
1270         struct net_device_stats *stats;
1271
1272         /* This needs to be able to handle ipddp"N" devices */
1273         if (!dev)
1274                 return -ENODEV;
1275
1276         skb->protocol = htons(ETH_P_IP);
1277         skb_pull(skb, 13);
1278         skb->dev   = dev;
1279         skb->h.raw = skb->data;
1280
1281         stats = dev->priv;
1282         stats->rx_packets++;
1283         stats->rx_bytes += skb->len + 13;
1284         netif_rx(skb);  /* Send the SKB up to a higher place. */
1285         return 0;
1286 }
1287 #else
1288 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1289 #define is_ip_over_ddp(skb) 0
1290 #define handle_ip_over_ddp(skb) 0
1291 #endif
1292
1293 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1294                                struct ddpehdr *ddp, struct ddpebits *ddphv,
1295                                int origlen)
1296 {
1297         struct atalk_route *rt;
1298         struct atalk_addr ta;
1299
1300         /*
1301          * Don't route multicast, etc., packets, or packets sent to "this
1302          * network" 
1303          */
1304         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1305                 /*
1306                  * FIXME:
1307                  *
1308                  * Can it ever happen that a packet is from a PPP iface and
1309                  * needs to be broadcast onto the default network?
1310                  */
1311                 if (dev->type == ARPHRD_PPP)
1312                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1313                                           "packet received from PPP iface\n");
1314                 goto free_it;
1315         }
1316
1317         ta.s_net  = ddp->deh_dnet;
1318         ta.s_node = ddp->deh_dnode;
1319
1320         /* Route the packet */
1321         rt = atrtr_find(&ta);
1322         if (!rt || ddphv->deh_hops == DDP_MAXHOPS)
1323                 goto free_it;
1324         /* FIXME: use skb->cb to be able to use shared skbs */
1325         ddphv->deh_hops++;
1326
1327         /*
1328          * Route goes through another gateway, so set the target to the
1329          * gateway instead.
1330          */
1331
1332         if (rt->flags & RTF_GATEWAY) {
1333                 ta.s_net  = rt->gateway.s_net;
1334                 ta.s_node = rt->gateway.s_node;
1335         }
1336
1337         /* Fix up skb->len field */
1338         skb_trim(skb, min_t(unsigned int, origlen,
1339                             (rt->dev->hard_header_len +
1340                              ddp_dl->header_length + ddphv->deh_len)));
1341
1342         /* Mend the byte order */
1343         /* FIXME: use skb->cb to be able to use shared skbs */
1344         *((__u16 *)ddp) = ntohs(*((__u16 *)ddphv));
1345
1346         /*
1347          * Send the buffer onwards
1348          *
1349          * Now we must always be careful. If it's come from LocalTalk to
1350          * EtherTalk it might not fit
1351          *
1352          * Order matters here: If a packet has to be copied to make a new
1353          * headroom (rare hopefully) then it won't need unsharing.
1354          *
1355          * Note. ddp-> becomes invalid at the realloc.
1356          */
1357         if (skb_headroom(skb) < 22) {
1358                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1359                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1360                 kfree_skb(skb);
1361                 if (!nskb) 
1362                         goto out;
1363                 skb = nskb;
1364         } else
1365                 skb = skb_unshare(skb, GFP_ATOMIC);
1366         
1367         /*
1368          * If the buffer didn't vanish into the lack of space bitbucket we can
1369          * send it.
1370          */
1371         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1372                 goto free_it;
1373 out:
1374         return;
1375 free_it:
1376         kfree_skb(skb);
1377 }
1378
1379 /**
1380  *      atalk_rcv - Receive a packet (in skb) from device dev
1381  *      @skb - packet received
1382  *      @dev - network device where the packet comes from
1383  *      @pt - packet type
1384  *
1385  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1386  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1387  *      header, skb->len is the DDP length. The physical headers have been
1388  *      extracted. PPP should probably pass frames marked as for this layer.
1389  *      [ie ARPHRD_ETHERTALK]
1390  */
1391 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1392                      struct packet_type *pt)
1393 {
1394         struct ddpehdr *ddp;
1395         struct sock *sock;
1396         struct atalk_iface *atif;
1397         struct sockaddr_at tosat;
1398         int origlen;
1399         struct ddpebits ddphv;
1400
1401         /* Don't mangle buffer if shared */
1402         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
1403                 goto out;
1404                 
1405         /* Size check and make sure header is contiguous */
1406         if (!pskb_may_pull(skb, sizeof(*ddp)))
1407                 goto freeit;
1408
1409         ddp = ddp_hdr(skb);
1410
1411         /*
1412          *      Fix up the length field [Ok this is horrible but otherwise
1413          *      I end up with unions of bit fields and messy bit field order
1414          *      compiler/endian dependencies..]
1415          */
1416         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1417
1418         /* Trim buffer in case of stray trailing data */
1419         origlen = skb->len;
1420         skb_trim(skb, min_t(unsigned int, skb->len, ddphv.deh_len));
1421
1422         /*
1423          * Size check to see if ddp->deh_len was crap
1424          * (Otherwise we'll detonate most spectacularly
1425          * in the middle of recvmsg()).
1426          */
1427         if (skb->len < sizeof(*ddp))
1428                 goto freeit;
1429
1430         /*
1431          * Any checksums. Note we don't do htons() on this == is assumed to be
1432          * valid for net byte orders all over the networking code...
1433          */
1434         if (ddp->deh_sum &&
1435             atalk_checksum(skb, ddphv.deh_len) != ddp->deh_sum)
1436                 /* Not a valid AppleTalk frame - dustbin time */
1437                 goto freeit;
1438
1439         /* Check the packet is aimed at us */
1440         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1441                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1442         else
1443                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1444
1445         /* Not ours, so we route the packet via the correct AppleTalk iface */
1446         if (!atif) {
1447                 atalk_route_packet(skb, dev, ddp, &ddphv, origlen);
1448                 goto out;
1449         }
1450
1451         /* if IP over DDP is not selected this code will be optimized out */
1452         if (is_ip_over_ddp(skb))
1453                 return handle_ip_over_ddp(skb);
1454         /*
1455          * Which socket - atalk_search_socket() looks for a *full match*
1456          * of the <net, node, port> tuple.
1457          */
1458         tosat.sat_addr.s_net  = ddp->deh_dnet;
1459         tosat.sat_addr.s_node = ddp->deh_dnode;
1460         tosat.sat_port        = ddp->deh_dport;
1461
1462         sock = atalk_search_socket(&tosat, atif);
1463         if (!sock) /* But not one of our sockets */
1464                 goto freeit;
1465
1466         /* Queue packet (standard) */
1467         skb->sk = sock;
1468
1469         if (sock_queue_rcv_skb(sock, skb) < 0)
1470                 goto freeit;
1471 out:
1472         return 0;
1473 freeit:
1474         kfree_skb(skb);
1475         goto out;
1476 }
1477
1478 /*
1479  * Receive a LocalTalk frame. We make some demands on the caller here.
1480  * Caller must provide enough headroom on the packet to pull the short
1481  * header and append a long one.
1482  */
1483 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1484                         struct packet_type *pt)
1485 {
1486         /* Expand any short form frames */
1487         if (skb->mac.raw[2] == 1) {
1488                 struct ddpehdr *ddp;
1489                 /* Find our address */
1490                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1491
1492                 if (!ap || skb->len < sizeof(struct ddpshdr))
1493                         goto freeit;
1494
1495                 /* Don't mangle buffer if shared */
1496                 if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
1497                         return 0;
1498
1499                 /*
1500                  * The push leaves us with a ddephdr not an shdr, and
1501                  * handily the port bytes in the right place preset.
1502                  */
1503                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1504
1505                 /* Now fill in the long header */
1506
1507                 /*
1508                  * These two first. The mac overlays the new source/dest
1509                  * network information so we MUST copy these before
1510                  * we write the network numbers !
1511                  */
1512
1513                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1514                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1515
1516                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1517                 ddp->deh_snet  = ap->s_net;
1518                 ddp->deh_sum   = 0;             /* No checksum */
1519                 /*
1520                  * Not sure about this bit...
1521                  */
1522                 ddp->deh_len   = skb->len;
1523                 ddp->deh_hops  = DDP_MAXHOPS;   /* Non routable, so force a drop
1524                                                    if we slip up later */
1525                 /* Mend the byte order */
1526                 *((__u16 *)ddp) = htons(*((__u16 *)ddp));
1527         }
1528         skb->h.raw = skb->data;
1529
1530         return atalk_rcv(skb, dev, pt);
1531 freeit:
1532         kfree_skb(skb);
1533         return 0;
1534 }
1535
1536 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1537                          size_t len)
1538 {
1539         struct sock *sk = sock->sk;
1540         struct atalk_sock *at = at_sk(sk);
1541         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1542         int flags = msg->msg_flags;
1543         int loopback = 0;
1544         struct sockaddr_at local_satalk, gsat;
1545         struct sk_buff *skb;
1546         struct net_device *dev;
1547         struct ddpehdr *ddp;
1548         int size;
1549         struct atalk_route *rt;
1550         int err;
1551
1552         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1553                 return -EINVAL;
1554
1555         if (len > DDP_MAXSZ)
1556                 return -EMSGSIZE;
1557
1558         if (usat) {
1559                 if (sock_flag(sk, SOCK_ZAPPED))
1560                         if (atalk_autobind(sk) < 0)
1561                                 return -EBUSY;
1562
1563                 if (msg->msg_namelen < sizeof(*usat) ||
1564                     usat->sat_family != AF_APPLETALK)
1565                         return -EINVAL;
1566
1567                 /* netatalk doesn't implement this check */
1568                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1569                     !sock_flag(sk, SOCK_BROADCAST)) {
1570                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1571                                          "it will break before 2.2\n");
1572 #if 0
1573                         return -EPERM;
1574 #endif
1575                 }
1576         } else {
1577                 if (sk->sk_state != TCP_ESTABLISHED)
1578                         return -ENOTCONN;
1579                 usat = &local_satalk;
1580                 usat->sat_family      = AF_APPLETALK;
1581                 usat->sat_port        = at->dest_port;
1582                 usat->sat_addr.s_node = at->dest_node;
1583                 usat->sat_addr.s_net  = at->dest_net;
1584         }
1585
1586         /* Build a packet */
1587         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1588
1589         /* For headers */
1590         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1591
1592         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1593                 rt = atrtr_find(&usat->sat_addr);
1594                 if (!rt)
1595                         return -ENETUNREACH;
1596
1597                 dev = rt->dev;
1598         } else {
1599                 struct atalk_addr at_hint;
1600
1601                 at_hint.s_node = 0;
1602                 at_hint.s_net  = at->src_net;
1603
1604                 rt = atrtr_find(&at_hint);
1605                 if (!rt)
1606                         return -ENETUNREACH;
1607
1608                 dev = rt->dev;
1609         }
1610
1611         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1612                         sk, size, dev->name);
1613
1614         size += dev->hard_header_len;
1615         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1616         if (!skb)
1617                 return err;
1618         
1619         skb->sk = sk;
1620         skb_reserve(skb, ddp_dl->header_length);
1621         skb_reserve(skb, dev->hard_header_len);
1622         skb->dev = dev;
1623
1624         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1625
1626         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1627         ddp->deh_pad  = 0;
1628         ddp->deh_hops = 0;
1629         ddp->deh_len  = len + sizeof(*ddp);
1630         /*
1631          * Fix up the length field [Ok this is horrible but otherwise
1632          * I end up with unions of bit fields and messy bit field order
1633          * compiler/endian dependencies..
1634          */
1635         *((__u16 *)ddp) = ntohs(*((__u16 *)ddp));
1636
1637         ddp->deh_dnet  = usat->sat_addr.s_net;
1638         ddp->deh_snet  = at->src_net;
1639         ddp->deh_dnode = usat->sat_addr.s_node;
1640         ddp->deh_snode = at->src_node;
1641         ddp->deh_dport = usat->sat_port;
1642         ddp->deh_sport = at->src_port;
1643
1644         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1645
1646         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1647         if (err) {
1648                 kfree_skb(skb);
1649                 return -EFAULT;
1650         }
1651
1652         if (sk->sk_no_check == 1)
1653                 ddp->deh_sum = 0;
1654         else
1655                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1656
1657         /*
1658          * Loopback broadcast packets to non gateway targets (ie routes
1659          * to group we are in)
1660          */
1661         if (ddp->deh_dnode == ATADDR_BCAST &&
1662             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1663                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1664
1665                 if (skb2) {
1666                         loopback = 1;
1667                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1668                         if (aarp_send_ddp(dev, skb2,
1669                                           &usat->sat_addr, NULL) == -1)
1670                                 kfree_skb(skb2);
1671                                 /* else queued/sent above in the aarp queue */
1672                 }
1673         }
1674
1675         if (dev->flags & IFF_LOOPBACK || loopback) {
1676                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1677                 /* loop back */
1678                 skb_orphan(skb);
1679                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1680         } else {
1681                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1682                 if (rt->flags & RTF_GATEWAY) {
1683                     gsat.sat_addr = rt->gateway;
1684                     usat = &gsat;
1685                 }
1686
1687                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1688                         kfree_skb(skb);
1689                 /* else queued/sent above in the aarp queue */
1690         }
1691         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1692
1693         return len;
1694 }
1695
1696 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1697                          size_t size, int flags)
1698 {
1699         struct sock *sk = sock->sk;
1700         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1701         struct ddpehdr *ddp;
1702         int copied = 0;
1703         int err = 0;
1704         struct ddpebits ddphv;
1705         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1706                                                 flags & MSG_DONTWAIT, &err);
1707         if (!skb)
1708                 return err;
1709
1710         /* FIXME: use skb->cb to be able to use shared skbs */
1711         ddp = ddp_hdr(skb);
1712         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1713
1714         if (sk->sk_type == SOCK_RAW) {
1715                 copied = ddphv.deh_len;
1716                 if (copied > size) {
1717                         copied = size;
1718                         msg->msg_flags |= MSG_TRUNC;
1719                 }
1720
1721                 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1722         } else {
1723                 copied = ddphv.deh_len - sizeof(*ddp);
1724                 if (copied > size) {
1725                         copied = size;
1726                         msg->msg_flags |= MSG_TRUNC;
1727                 }
1728                 err = skb_copy_datagram_iovec(skb, sizeof(*ddp),
1729                                               msg->msg_iov, copied);
1730         }
1731
1732         if (!err) {
1733                 if (sat) {
1734                         sat->sat_family      = AF_APPLETALK;
1735                         sat->sat_port        = ddp->deh_sport;
1736                         sat->sat_addr.s_node = ddp->deh_snode;
1737                         sat->sat_addr.s_net  = ddp->deh_snet;
1738                 }
1739                 msg->msg_namelen = sizeof(*sat);
1740         }
1741
1742         skb_free_datagram(sk, skb);     /* Free the datagram. */
1743         return err ? : copied;
1744 }
1745
1746
1747 /*
1748  * AppleTalk ioctl calls.
1749  */
1750 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1751 {
1752         int rc = -EINVAL;
1753         struct sock *sk = sock->sk;
1754         void __user *argp = (void __user *)arg;
1755
1756         switch (cmd) {
1757                 /* Protocol layer */
1758                 case TIOCOUTQ: {
1759                         long amount = sk->sk_sndbuf -
1760                                       atomic_read(&sk->sk_wmem_alloc);
1761
1762                         if (amount < 0)
1763                                 amount = 0;
1764                         rc = put_user(amount, (int __user *)argp);
1765                         break;
1766                 }
1767                 case TIOCINQ: {
1768                         /*
1769                          * These two are safe on a single CPU system as only
1770                          * user tasks fiddle here
1771                          */
1772                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1773                         long amount = 0;
1774
1775                         if (skb)
1776                                 amount = skb->len - sizeof(struct ddpehdr);
1777                         rc = put_user(amount, (int __user *)argp);
1778                         break;
1779                 }
1780                 case SIOCGSTAMP:
1781                         rc = sock_get_timestamp(sk, argp);
1782                         break;
1783                 /* Routing */
1784                 case SIOCADDRT:
1785                 case SIOCDELRT:
1786                         rc = -EPERM;
1787                         if (capable(CAP_NET_ADMIN))
1788                                 rc = atrtr_ioctl(cmd, argp);
1789                         break;
1790                 /* Interface */
1791                 case SIOCGIFADDR:
1792                 case SIOCSIFADDR:
1793                 case SIOCGIFBRDADDR:
1794                 case SIOCATALKDIFADDR:
1795                 case SIOCDIFADDR:
1796                 case SIOCSARP:          /* proxy AARP */
1797                 case SIOCDARP:          /* proxy AARP */
1798                         rtnl_lock();
1799                         rc = atif_ioctl(cmd, argp);
1800                         rtnl_unlock();
1801                         break;
1802                 /* Physical layer ioctl calls */
1803                 case SIOCSIFLINK:
1804                 case SIOCGIFHWADDR:
1805                 case SIOCSIFHWADDR:
1806                 case SIOCGIFFLAGS:
1807                 case SIOCSIFFLAGS:
1808                 case SIOCGIFTXQLEN:
1809                 case SIOCSIFTXQLEN:
1810                 case SIOCGIFMTU:
1811                 case SIOCGIFCONF:
1812                 case SIOCADDMULTI:
1813                 case SIOCDELMULTI:
1814                 case SIOCGIFCOUNT:
1815                 case SIOCGIFINDEX:
1816                 case SIOCGIFNAME:
1817                         rc = dev_ioctl(cmd, argp);
1818                         break;
1819         }
1820
1821         return rc;
1822 }
1823
1824 static struct net_proto_family atalk_family_ops = {
1825         .family         = PF_APPLETALK,
1826         .create         = atalk_create,
1827         .owner          = THIS_MODULE,
1828 };
1829
1830 static struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1831         .family         = PF_APPLETALK,
1832         .owner          = THIS_MODULE,
1833         .release        = atalk_release,
1834         .bind           = atalk_bind,
1835         .connect        = atalk_connect,
1836         .socketpair     = sock_no_socketpair,
1837         .accept         = sock_no_accept,
1838         .getname        = atalk_getname,
1839         .poll           = datagram_poll,
1840         .ioctl          = atalk_ioctl,
1841         .listen         = sock_no_listen,
1842         .shutdown       = sock_no_shutdown,
1843         .setsockopt     = sock_no_setsockopt,
1844         .getsockopt     = sock_no_getsockopt,
1845         .sendmsg        = atalk_sendmsg,
1846         .recvmsg        = atalk_recvmsg,
1847         .mmap           = sock_no_mmap,
1848         .sendpage       = sock_no_sendpage,
1849 };
1850
1851 #include <linux/smp_lock.h>
1852 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1853
1854 static struct notifier_block ddp_notifier = {
1855         .notifier_call  = ddp_device_event,
1856 };
1857
1858 static struct packet_type ltalk_packet_type = {
1859         .type           = __constant_htons(ETH_P_LOCALTALK),
1860         .func           = ltalk_rcv,
1861 };
1862
1863 static struct packet_type ppptalk_packet_type = {
1864         .type           = __constant_htons(ETH_P_PPPTALK),
1865         .func           = atalk_rcv,
1866 };
1867
1868 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1869
1870 /* Export symbols for use by drivers when AppleTalk is a module */
1871 EXPORT_SYMBOL(aarp_send_ddp);
1872 EXPORT_SYMBOL(atrtr_get_dev);
1873 EXPORT_SYMBOL(atalk_find_dev_addr);
1874
1875 static char atalk_err_snap[] __initdata =
1876         KERN_CRIT "Unable to register DDP with SNAP.\n";
1877
1878 /* Called by proto.c on kernel start up */
1879 static int __init atalk_init(void)
1880 {
1881         int rc = proto_register(&ddp_proto, 0);
1882
1883         if (rc != 0)
1884                 goto out;
1885
1886         (void)sock_register(&atalk_family_ops);
1887         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1888         if (!ddp_dl)
1889                 printk(atalk_err_snap);
1890
1891         dev_add_pack(&ltalk_packet_type);
1892         dev_add_pack(&ppptalk_packet_type);
1893
1894         register_netdevice_notifier(&ddp_notifier);
1895         aarp_proto_init();
1896         atalk_proc_init();
1897         atalk_register_sysctl();
1898 out:
1899         return rc;
1900 }
1901 module_init(atalk_init);
1902
1903 /*
1904  * No explicit module reference count manipulation is needed in the
1905  * protocol. Socket layer sets module reference count for us
1906  * and interfaces reference counting is done
1907  * by the network device layer.
1908  *
1909  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1910  * sockets be closed from user space.
1911  */
1912 static void __exit atalk_exit(void)
1913 {
1914 #ifdef CONFIG_SYSCTL
1915         atalk_unregister_sysctl();
1916 #endif /* CONFIG_SYSCTL */
1917         atalk_proc_exit();
1918         aarp_cleanup_module();  /* General aarp clean-up. */
1919         unregister_netdevice_notifier(&ddp_notifier);
1920         dev_remove_pack(&ltalk_packet_type);
1921         dev_remove_pack(&ppptalk_packet_type);
1922         unregister_snap_client(ddp_dl);
1923         sock_unregister(PF_APPLETALK);
1924         proto_unregister(&ddp_proto);
1925 }
1926 module_exit(atalk_exit);
1927
1928 MODULE_LICENSE("GPL");
1929 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1930 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1931 MODULE_ALIAS_NETPROTO(PF_APPLETALK);