[ATALK]: endianness annotations
[linux-2.6.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
65 struct datalink_proto *ddp_dl, *aarp_dl;
66 static const 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                         goto found;
105
106                 if (to->sat_addr.s_net == at->src_net &&
107                     (to->sat_addr.s_node == at->src_node ||
108                      to->sat_addr.s_node == ATADDR_BCAST ||
109                      to->sat_addr.s_node == ATADDR_ANYNODE))
110                         goto found;
111
112                 /* XXXX.0 -- we got a request for this router. make sure
113                  * that the node is appropriately set. */
114                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
115                     to->sat_addr.s_net != ATADDR_ANYNET &&
116                     atif->address.s_node == at->src_node) {
117                         to->sat_addr.s_node = atif->address.s_node;
118                         goto found;
119                 }
120         }
121         s = NULL;
122 found:
123         read_unlock_bh(&atalk_sockets_lock);
124         return s;
125 }
126
127 /**
128  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
129  * @sk - socket to insert in the list if it is not there already
130  * @sat - address to search for
131  *
132  * Try to find a socket matching ADDR in the socket list, if found then return
133  * it. If not, insert SK into the socket list.
134  *
135  * This entire operation must execute atomically.
136  */
137 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
138                                                 struct sockaddr_at *sat)
139 {
140         struct sock *s;
141         struct hlist_node *node;
142         struct atalk_sock *at;
143
144         write_lock_bh(&atalk_sockets_lock);
145         sk_for_each(s, node, &atalk_sockets) {
146                 at = at_sk(s);
147
148                 if (at->src_net == sat->sat_addr.s_net &&
149                     at->src_node == sat->sat_addr.s_node &&
150                     at->src_port == sat->sat_port)
151                         goto found;
152         }
153         s = NULL;
154         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
155 found:
156         write_unlock_bh(&atalk_sockets_lock);
157         return s;
158 }
159
160 static void atalk_destroy_timer(unsigned long data)
161 {
162         struct sock *sk = (struct sock *)data;
163
164         if (atomic_read(&sk->sk_wmem_alloc) ||
165             atomic_read(&sk->sk_rmem_alloc)) {
166                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
167                 add_timer(&sk->sk_timer);
168         } else
169                 sock_put(sk);
170 }
171
172 static inline void atalk_destroy_socket(struct sock *sk)
173 {
174         atalk_remove_socket(sk);
175         skb_queue_purge(&sk->sk_receive_queue);
176
177         if (atomic_read(&sk->sk_wmem_alloc) ||
178             atomic_read(&sk->sk_rmem_alloc)) {
179                 init_timer(&sk->sk_timer);
180                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
181                 sk->sk_timer.function   = atalk_destroy_timer;
182                 sk->sk_timer.data       = (unsigned long)sk;
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         if (event == NETDEV_DOWN)
650                 /* Discard any use of this */
651                 atalk_dev_down(ptr);
652
653         return NOTIFY_DONE;
654 }
655
656 /* ioctl calls. Shouldn't even need touching */
657 /* Device configuration ioctl calls */
658 static int atif_ioctl(int cmd, void __user *arg)
659 {
660         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
661         struct ifreq atreq;
662         struct atalk_netrange *nr;
663         struct sockaddr_at *sa;
664         struct net_device *dev;
665         struct atalk_iface *atif;
666         int ct;
667         int limit;
668         struct rtentry rtdef;
669         int add_route;
670
671         if (copy_from_user(&atreq, arg, sizeof(atreq)))
672                 return -EFAULT;
673
674         dev = __dev_get_by_name(atreq.ifr_name);
675         if (!dev)
676                 return -ENODEV;
677
678         sa = (struct sockaddr_at *)&atreq.ifr_addr;
679         atif = atalk_find_dev(dev);
680
681         switch (cmd) {
682                 case SIOCSIFADDR:
683                         if (!capable(CAP_NET_ADMIN))
684                                 return -EPERM;
685                         if (sa->sat_family != AF_APPLETALK)
686                                 return -EINVAL;
687                         if (dev->type != ARPHRD_ETHER &&
688                             dev->type != ARPHRD_LOOPBACK &&
689                             dev->type != ARPHRD_LOCALTLK &&
690                             dev->type != ARPHRD_PPP)
691                                 return -EPROTONOSUPPORT;
692
693                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
694                         add_route = 1;
695
696                         /*
697                          * if this is a point-to-point iface, and we already
698                          * have an iface for this AppleTalk address, then we
699                          * should not add a route
700                          */
701                         if ((dev->flags & IFF_POINTOPOINT) &&
702                             atalk_find_interface(sa->sat_addr.s_net,
703                                                  sa->sat_addr.s_node)) {
704                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
705                                                   "interface added with "
706                                                   "existing address\n");
707                                 add_route = 0;
708                         }
709                         
710                         /*
711                          * Phase 1 is fine on LocalTalk but we don't do
712                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
713                          */
714                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
715                                 return -EPROTONOSUPPORT;
716                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
717                             sa->sat_addr.s_node == 254)
718                                 return -EINVAL;
719                         if (atif) {
720                                 /* Already setting address */
721                                 if (atif->status & ATIF_PROBE)
722                                         return -EBUSY;
723
724                                 atif->address.s_net  = sa->sat_addr.s_net;
725                                 atif->address.s_node = sa->sat_addr.s_node;
726                                 atrtr_device_down(dev); /* Flush old routes */
727                         } else {
728                                 atif = atif_add_device(dev, &sa->sat_addr);
729                                 if (!atif)
730                                         return -ENOMEM;
731                         }
732                         atif->nets = *nr;
733
734                         /*
735                          * Check if the chosen address is used. If so we
736                          * error and atalkd will try another.
737                          */
738
739                         if (!(dev->flags & IFF_LOOPBACK) &&
740                             !(dev->flags & IFF_POINTOPOINT) &&
741                             atif_probe_device(atif) < 0) {
742                                 atif_drop_device(dev);
743                                 return -EADDRINUSE;
744                         }
745
746                         /* Hey it worked - add the direct routes */
747                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
748                         sa->sat_family = AF_APPLETALK;
749                         sa->sat_addr.s_net  = atif->address.s_net;
750                         sa->sat_addr.s_node = atif->address.s_node;
751                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
752                         rtdef.rt_flags = RTF_UP;
753                         sa->sat_family = AF_APPLETALK;
754                         sa->sat_addr.s_node = ATADDR_ANYNODE;
755                         if (dev->flags & IFF_LOOPBACK ||
756                             dev->flags & IFF_POINTOPOINT)
757                                 rtdef.rt_flags |= RTF_HOST;
758
759                         /* Routerless initial state */
760                         if (nr->nr_firstnet == htons(0) &&
761                             nr->nr_lastnet == htons(0xFFFE)) {
762                                 sa->sat_addr.s_net = atif->address.s_net;
763                                 atrtr_create(&rtdef, dev);
764                                 atrtr_set_default(dev);
765                         } else {
766                                 limit = ntohs(nr->nr_lastnet);
767                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
768                                         printk(KERN_WARNING "Too many routes/"
769                                                             "iface.\n");
770                                         return -EINVAL;
771                                 }
772                                 if (add_route)
773                                         for (ct = ntohs(nr->nr_firstnet);
774                                              ct <= limit; ct++) {
775                                                 sa->sat_addr.s_net = htons(ct);
776                                                 atrtr_create(&rtdef, dev);
777                                         }
778                         }
779                         dev_mc_add(dev, aarp_mcast, 6, 1);
780                         return 0;
781
782                 case SIOCGIFADDR:
783                         if (!atif)
784                                 return -EADDRNOTAVAIL;
785
786                         sa->sat_family = AF_APPLETALK;
787                         sa->sat_addr = atif->address;
788                         break;
789
790                 case SIOCGIFBRDADDR:
791                         if (!atif)
792                                 return -EADDRNOTAVAIL;
793
794                         sa->sat_family = AF_APPLETALK;
795                         sa->sat_addr.s_net = atif->address.s_net;
796                         sa->sat_addr.s_node = ATADDR_BCAST;
797                         break;
798
799                 case SIOCATALKDIFADDR:
800                 case SIOCDIFADDR:
801                         if (!capable(CAP_NET_ADMIN))
802                                 return -EPERM;
803                         if (sa->sat_family != AF_APPLETALK)
804                                 return -EINVAL;
805                         atalk_dev_down(dev);
806                         break;                  
807
808                 case SIOCSARP:
809                         if (!capable(CAP_NET_ADMIN))
810                                 return -EPERM;
811                         if (sa->sat_family != AF_APPLETALK)
812                                 return -EINVAL;
813                         if (!atif)
814                                 return -EADDRNOTAVAIL;
815
816                         /*
817                          * for now, we only support proxy AARP on ELAP;
818                          * we should be able to do it for LocalTalk, too.
819                          */
820                         if (dev->type != ARPHRD_ETHER)
821                                 return -EPROTONOSUPPORT;
822
823                         /*
824                          * atif points to the current interface on this network;
825                          * we aren't concerned about its current status (at
826                          * least for now), but it has all the settings about
827                          * the network we're going to probe. Consequently, it
828                          * must exist.
829                          */
830                         if (!atif)
831                                 return -EADDRNOTAVAIL;
832
833                         nr = (struct atalk_netrange *)&(atif->nets);
834                         /*
835                          * Phase 1 is fine on Localtalk but we don't do
836                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
837                          */
838                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
839                                 return -EPROTONOSUPPORT;
840
841                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
842                             sa->sat_addr.s_node == 254)
843                                 return -EINVAL;
844
845                         /*
846                          * Check if the chosen address is used. If so we
847                          * error and ATCP will try another.
848                          */
849                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
850                                 return -EADDRINUSE;
851                         
852                         /*
853                          * We now have an address on the local network, and
854                          * the AARP code will defend it for us until we take it
855                          * down. We don't set up any routes right now, because
856                          * ATCP will install them manually via SIOCADDRT.
857                          */
858                         break;
859
860                 case SIOCDARP:
861                         if (!capable(CAP_NET_ADMIN))
862                                 return -EPERM;
863                         if (sa->sat_family != AF_APPLETALK)
864                                 return -EINVAL;
865                         if (!atif)
866                                 return -EADDRNOTAVAIL;
867
868                         /* give to aarp module to remove proxy entry */
869                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
870                         return 0;
871         }
872
873         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
874 }
875
876 /* Routing ioctl() calls */
877 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
878 {
879         struct rtentry rt;
880
881         if (copy_from_user(&rt, arg, sizeof(rt)))
882                 return -EFAULT;
883
884         switch (cmd) {
885                 case SIOCDELRT:
886                         if (rt.rt_dst.sa_family != AF_APPLETALK)
887                                 return -EINVAL;
888                         return atrtr_delete(&((struct sockaddr_at *)
889                                                 &rt.rt_dst)->sat_addr);
890
891                 case SIOCADDRT: {
892                         struct net_device *dev = NULL;
893                         if (rt.rt_dev) {
894                                 char name[IFNAMSIZ];
895                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
896                                         return -EFAULT;
897                                 name[IFNAMSIZ-1] = '\0';
898                                 dev = __dev_get_by_name(name);
899                                 if (!dev)
900                                         return -ENODEV;
901                         }                       
902                         return atrtr_create(&rt, dev);
903                 }
904         }
905         return -EINVAL;
906 }
907
908 /**************************************************************************\
909 *                                                                          *
910 * Handling for system calls applied via the various interfaces to an       *
911 * AppleTalk socket object.                                                 *
912 *                                                                          *
913 \**************************************************************************/
914
915 /*
916  * Checksum: This is 'optional'. It's quite likely also a good
917  * candidate for assembler hackery 8)
918  */
919 static unsigned long atalk_sum_partial(const unsigned char *data, 
920                                        int len, unsigned long sum)
921 {
922         /* This ought to be unwrapped neatly. I'll trust gcc for now */
923         while (len--) {
924                 sum += *data;
925                 sum <<= 1;
926                 if (sum & 0x10000) {
927                         sum++;
928                         sum &= 0xffff;
929                 }
930                 data++;
931         }
932         return sum;
933 }
934
935 /*  Checksum skb data --  similar to skb_checksum  */
936 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
937                                    int len, unsigned long sum)
938 {
939         int start = skb_headlen(skb);
940         int i, copy;
941
942         /* checksum stuff in header space */
943         if ( (copy = start - offset) > 0) {
944                 if (copy > len)
945                         copy = len;
946                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
947                 if ( (len -= copy) == 0) 
948                         return sum;
949
950                 offset += copy;
951         }
952
953         /* checksum stuff in frags */
954         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
955                 int end;
956
957                 BUG_TRAP(start <= offset + len);
958
959                 end = start + skb_shinfo(skb)->frags[i].size;
960                 if ((copy = end - offset) > 0) {
961                         u8 *vaddr;
962                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
963
964                         if (copy > len)
965                                 copy = len;
966                         vaddr = kmap_skb_frag(frag);
967                         sum = atalk_sum_partial(vaddr + frag->page_offset +
968                                                   offset - start, copy, sum);
969                         kunmap_skb_frag(vaddr);
970
971                         if (!(len -= copy))
972                                 return sum;
973                         offset += copy;
974                 }
975                 start = end;
976         }
977
978         if (skb_shinfo(skb)->frag_list) {
979                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
980
981                 for (; list; list = list->next) {
982                         int end;
983
984                         BUG_TRAP(start <= offset + len);
985
986                         end = start + list->len;
987                         if ((copy = end - offset) > 0) {
988                                 if (copy > len)
989                                         copy = len;
990                                 sum = atalk_sum_skb(list, offset - start,
991                                                     copy, sum);
992                                 if ((len -= copy) == 0)
993                                         return sum;
994                                 offset += copy;
995                         }
996                         start = end;
997                 }
998         }
999
1000         BUG_ON(len > 0);
1001
1002         return sum;
1003 }
1004
1005 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1006 {
1007         unsigned long sum;
1008
1009         /* skip header 4 bytes */
1010         sum = atalk_sum_skb(skb, 4, len-4, 0);
1011
1012         /* Use 0xFFFF for 0. 0 itself means none */
1013         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1014 }
1015
1016 static struct proto ddp_proto = {
1017         .name     = "DDP",
1018         .owner    = THIS_MODULE,
1019         .obj_size = sizeof(struct atalk_sock),
1020 };
1021
1022 /*
1023  * Create a socket. Initialise the socket, blank the addresses
1024  * set the state.
1025  */
1026 static int atalk_create(struct socket *sock, int protocol)
1027 {
1028         struct sock *sk;
1029         int rc = -ESOCKTNOSUPPORT;
1030
1031         /*
1032          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1033          * and gives you the full ELAP frame. Should be handy for CAP 8) 
1034          */
1035         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1036                 goto out;
1037         rc = -ENOMEM;
1038         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1039         if (!sk)
1040                 goto out;
1041         rc = 0;
1042         sock->ops = &atalk_dgram_ops;
1043         sock_init_data(sock, sk);
1044
1045         /* Checksums on by default */
1046         sock_set_flag(sk, SOCK_ZAPPED);
1047 out:
1048         return rc;
1049 }
1050
1051 /* Free a socket. No work needed */
1052 static int atalk_release(struct socket *sock)
1053 {
1054         struct sock *sk = sock->sk;
1055
1056         if (sk) {
1057                 sock_orphan(sk);
1058                 sock->sk = NULL;
1059                 atalk_destroy_socket(sk);
1060         }
1061         return 0;
1062 }
1063
1064 /**
1065  * atalk_pick_and_bind_port - Pick a source port when one is not given
1066  * @sk - socket to insert into the tables
1067  * @sat - address to search for
1068  *
1069  * Pick a source port when one is not given. If we can find a suitable free
1070  * one, we insert the socket into the tables using it.
1071  *
1072  * This whole operation must be atomic.
1073  */
1074 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1075 {
1076         int retval;
1077
1078         write_lock_bh(&atalk_sockets_lock);
1079
1080         for (sat->sat_port = ATPORT_RESERVED;
1081              sat->sat_port < ATPORT_LAST;
1082              sat->sat_port++) {
1083                 struct sock *s;
1084                 struct hlist_node *node;
1085
1086                 sk_for_each(s, node, &atalk_sockets) {
1087                         struct atalk_sock *at = at_sk(s);
1088
1089                         if (at->src_net == sat->sat_addr.s_net &&
1090                             at->src_node == sat->sat_addr.s_node &&
1091                             at->src_port == sat->sat_port)
1092                                 goto try_next_port;
1093                 }
1094
1095                 /* Wheee, it's free, assign and insert. */
1096                 __atalk_insert_socket(sk);
1097                 at_sk(sk)->src_port = sat->sat_port;
1098                 retval = 0;
1099                 goto out;
1100
1101 try_next_port:;
1102         }
1103
1104         retval = -EBUSY;
1105 out:
1106         write_unlock_bh(&atalk_sockets_lock);
1107         return retval;
1108 }
1109
1110 static int atalk_autobind(struct sock *sk)
1111 {
1112         struct atalk_sock *at = at_sk(sk);
1113         struct sockaddr_at sat;
1114         struct atalk_addr *ap = atalk_find_primary();
1115         int n = -EADDRNOTAVAIL;
1116
1117         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1118                 goto out;
1119
1120         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1121         at->src_node = sat.sat_addr.s_node = ap->s_node;
1122
1123         n = atalk_pick_and_bind_port(sk, &sat);
1124         if (!n)
1125                 sock_reset_flag(sk, SOCK_ZAPPED);
1126 out:
1127         return n;
1128 }
1129
1130 /* Set the address 'our end' of the connection */
1131 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1132 {
1133         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1134         struct sock *sk = sock->sk;
1135         struct atalk_sock *at = at_sk(sk);
1136
1137         if (!sock_flag(sk, SOCK_ZAPPED) ||
1138             addr_len != sizeof(struct sockaddr_at))
1139                 return -EINVAL;
1140
1141         if (addr->sat_family != AF_APPLETALK)
1142                 return -EAFNOSUPPORT;
1143
1144         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1145                 struct atalk_addr *ap = atalk_find_primary();
1146
1147                 if (!ap)
1148                         return -EADDRNOTAVAIL;
1149
1150                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1151                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1152         } else {
1153                 if (!atalk_find_interface(addr->sat_addr.s_net,
1154                                           addr->sat_addr.s_node))
1155                         return -EADDRNOTAVAIL;
1156
1157                 at->src_net  = addr->sat_addr.s_net;
1158                 at->src_node = addr->sat_addr.s_node;
1159         }
1160
1161         if (addr->sat_port == ATADDR_ANYPORT) {
1162                 int n = atalk_pick_and_bind_port(sk, addr);
1163
1164                 if (n < 0)
1165                         return n;
1166         } else {
1167                 at->src_port = addr->sat_port;
1168
1169                 if (atalk_find_or_insert_socket(sk, addr))
1170                         return -EADDRINUSE;
1171         }
1172
1173         sock_reset_flag(sk, SOCK_ZAPPED);
1174         return 0;
1175 }
1176
1177 /* Set the address we talk to */
1178 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1179                          int addr_len, int flags)
1180 {
1181         struct sock *sk = sock->sk;
1182         struct atalk_sock *at = at_sk(sk);
1183         struct sockaddr_at *addr;
1184
1185         sk->sk_state   = TCP_CLOSE;
1186         sock->state = SS_UNCONNECTED;
1187
1188         if (addr_len != sizeof(*addr))
1189                 return -EINVAL;
1190
1191         addr = (struct sockaddr_at *)uaddr;
1192
1193         if (addr->sat_family != AF_APPLETALK)
1194                 return -EAFNOSUPPORT;
1195
1196         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1197             !sock_flag(sk, SOCK_BROADCAST)) {
1198 #if 1   
1199                 printk(KERN_WARNING "%s is broken and did not set "
1200                                     "SO_BROADCAST. It will break when 2.2 is "
1201                                     "released.\n",
1202                         current->comm);
1203 #else
1204                 return -EACCES;
1205 #endif                  
1206         }
1207
1208         if (sock_flag(sk, SOCK_ZAPPED))
1209                 if (atalk_autobind(sk) < 0)
1210                         return -EBUSY;
1211
1212         if (!atrtr_get_dev(&addr->sat_addr))
1213                 return -ENETUNREACH;
1214
1215         at->dest_port = addr->sat_port;
1216         at->dest_net  = addr->sat_addr.s_net;
1217         at->dest_node = addr->sat_addr.s_node;
1218
1219         sock->state  = SS_CONNECTED;
1220         sk->sk_state = TCP_ESTABLISHED;
1221         return 0;
1222 }
1223
1224 /*
1225  * Find the name of an AppleTalk socket. Just copy the right
1226  * fields into the sockaddr.
1227  */
1228 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1229                          int *uaddr_len, int peer)
1230 {
1231         struct sockaddr_at sat;
1232         struct sock *sk = sock->sk;
1233         struct atalk_sock *at = at_sk(sk);
1234
1235         if (sock_flag(sk, SOCK_ZAPPED))
1236                 if (atalk_autobind(sk) < 0)
1237                         return -ENOBUFS;
1238
1239         *uaddr_len = sizeof(struct sockaddr_at);
1240
1241         if (peer) {
1242                 if (sk->sk_state != TCP_ESTABLISHED)
1243                         return -ENOTCONN;
1244
1245                 sat.sat_addr.s_net  = at->dest_net;
1246                 sat.sat_addr.s_node = at->dest_node;
1247                 sat.sat_port        = at->dest_port;
1248         } else {
1249                 sat.sat_addr.s_net  = at->src_net;
1250                 sat.sat_addr.s_node = at->src_node;
1251                 sat.sat_port        = at->src_port;
1252         }
1253
1254         sat.sat_family = AF_APPLETALK;
1255         memcpy(uaddr, &sat, sizeof(sat));
1256         return 0;
1257 }
1258
1259 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1260 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1261 {
1262         return skb->data[12] == 22;
1263 }
1264
1265 static int handle_ip_over_ddp(struct sk_buff *skb)
1266 {
1267         struct net_device *dev = __dev_get_by_name("ipddp0");
1268         struct net_device_stats *stats;
1269
1270         /* This needs to be able to handle ipddp"N" devices */
1271         if (!dev)
1272                 return -ENODEV;
1273
1274         skb->protocol = htons(ETH_P_IP);
1275         skb_pull(skb, 13);
1276         skb->dev   = dev;
1277         skb->h.raw = skb->data;
1278
1279         stats = dev->priv;
1280         stats->rx_packets++;
1281         stats->rx_bytes += skb->len + 13;
1282         netif_rx(skb);  /* Send the SKB up to a higher place. */
1283         return 0;
1284 }
1285 #else
1286 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1287 #define is_ip_over_ddp(skb) 0
1288 #define handle_ip_over_ddp(skb) 0
1289 #endif
1290
1291 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1292                                struct ddpehdr *ddp, __u16 len_hops,
1293                                int origlen)
1294 {
1295         struct atalk_route *rt;
1296         struct atalk_addr ta;
1297
1298         /*
1299          * Don't route multicast, etc., packets, or packets sent to "this
1300          * network" 
1301          */
1302         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1303                 /*
1304                  * FIXME:
1305                  *
1306                  * Can it ever happen that a packet is from a PPP iface and
1307                  * needs to be broadcast onto the default network?
1308                  */
1309                 if (dev->type == ARPHRD_PPP)
1310                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1311                                           "packet received from PPP iface\n");
1312                 goto free_it;
1313         }
1314
1315         ta.s_net  = ddp->deh_dnet;
1316         ta.s_node = ddp->deh_dnode;
1317
1318         /* Route the packet */
1319         rt = atrtr_find(&ta);
1320         /* increment hops count */
1321         len_hops += 1 << 10;
1322         if (!rt || !(len_hops & (15 << 10)))
1323                 goto free_it;
1324
1325         /* FIXME: use skb->cb to be able to use shared skbs */
1326
1327         /*
1328          * Route goes through another gateway, so set the target to the
1329          * gateway instead.
1330          */
1331
1332         if (rt->flags & RTF_GATEWAY) {
1333                 ta.s_net  = rt->gateway.s_net;
1334                 ta.s_node = rt->gateway.s_node;
1335         }
1336
1337         /* Fix up skb->len field */
1338         skb_trim(skb, min_t(unsigned int, origlen,
1339                             (rt->dev->hard_header_len +
1340                              ddp_dl->header_length + (len_hops & 1023))));
1341
1342         /* FIXME: use skb->cb to be able to use shared skbs */
1343         ddp->deh_len_hops = htons(len_hops);
1344
1345         /*
1346          * Send the buffer onwards
1347          *
1348          * Now we must always be careful. If it's come from LocalTalk to
1349          * EtherTalk it might not fit
1350          *
1351          * Order matters here: If a packet has to be copied to make a new
1352          * headroom (rare hopefully) then it won't need unsharing.
1353          *
1354          * Note. ddp-> becomes invalid at the realloc.
1355          */
1356         if (skb_headroom(skb) < 22) {
1357                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1358                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1359                 kfree_skb(skb);
1360                 if (!nskb) 
1361                         goto out;
1362                 skb = nskb;
1363         } else
1364                 skb = skb_unshare(skb, GFP_ATOMIC);
1365         
1366         /*
1367          * If the buffer didn't vanish into the lack of space bitbucket we can
1368          * send it.
1369          */
1370         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1371                 goto free_it;
1372 out:
1373         return;
1374 free_it:
1375         kfree_skb(skb);
1376 }
1377
1378 /**
1379  *      atalk_rcv - Receive a packet (in skb) from device dev
1380  *      @skb - packet received
1381  *      @dev - network device where the packet comes from
1382  *      @pt - packet type
1383  *
1384  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1385  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1386  *      header, skb->len is the DDP length. The physical headers have been
1387  *      extracted. PPP should probably pass frames marked as for this layer.
1388  *      [ie ARPHRD_ETHERTALK]
1389  */
1390 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1391                      struct packet_type *pt, struct net_device *orig_dev)
1392 {
1393         struct ddpehdr *ddp;
1394         struct sock *sock;
1395         struct atalk_iface *atif;
1396         struct sockaddr_at tosat;
1397         int origlen;
1398         __u16 len_hops;
1399
1400         /* Don't mangle buffer if shared */
1401         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
1402                 goto out;
1403                 
1404         /* Size check and make sure header is contiguous */
1405         if (!pskb_may_pull(skb, sizeof(*ddp)))
1406                 goto freeit;
1407
1408         ddp = ddp_hdr(skb);
1409
1410         len_hops = ntohs(ddp->deh_len_hops);
1411
1412         /* Trim buffer in case of stray trailing data */
1413         origlen = skb->len;
1414         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1415
1416         /*
1417          * Size check to see if ddp->deh_len was crap
1418          * (Otherwise we'll detonate most spectacularly
1419          * in the middle of recvmsg()).
1420          */
1421         if (skb->len < sizeof(*ddp))
1422                 goto freeit;
1423
1424         /*
1425          * Any checksums. Note we don't do htons() on this == is assumed to be
1426          * valid for net byte orders all over the networking code...
1427          */
1428         if (ddp->deh_sum &&
1429             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1430                 /* Not a valid AppleTalk frame - dustbin time */
1431                 goto freeit;
1432
1433         /* Check the packet is aimed at us */
1434         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1435                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1436         else
1437                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1438
1439         if (!atif) {
1440                 /* Not ours, so we route the packet via the correct
1441                  * AppleTalk iface
1442                  */
1443                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1444                 goto out;
1445         }
1446
1447         /* if IP over DDP is not selected this code will be optimized out */
1448         if (is_ip_over_ddp(skb))
1449                 return handle_ip_over_ddp(skb);
1450         /*
1451          * Which socket - atalk_search_socket() looks for a *full match*
1452          * of the <net, node, port> tuple.
1453          */
1454         tosat.sat_addr.s_net  = ddp->deh_dnet;
1455         tosat.sat_addr.s_node = ddp->deh_dnode;
1456         tosat.sat_port        = ddp->deh_dport;
1457
1458         sock = atalk_search_socket(&tosat, atif);
1459         if (!sock) /* But not one of our sockets */
1460                 goto freeit;
1461
1462         /* Queue packet (standard) */
1463         skb->sk = sock;
1464
1465         if (sock_queue_rcv_skb(sock, skb) < 0)
1466                 goto freeit;
1467 out:
1468         return 0;
1469 freeit:
1470         kfree_skb(skb);
1471         goto out;
1472 }
1473
1474 /*
1475  * Receive a LocalTalk frame. We make some demands on the caller here.
1476  * Caller must provide enough headroom on the packet to pull the short
1477  * header and append a long one.
1478  */
1479 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1480                      struct packet_type *pt, struct net_device *orig_dev)
1481 {
1482         /* Expand any short form frames */
1483         if (skb->mac.raw[2] == 1) {
1484                 struct ddpehdr *ddp;
1485                 /* Find our address */
1486                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1487
1488                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1489                         goto freeit;
1490
1491                 /* Don't mangle buffer if shared */
1492                 if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
1493                         return 0;
1494
1495                 /*
1496                  * The push leaves us with a ddephdr not an shdr, and
1497                  * handily the port bytes in the right place preset.
1498                  */
1499                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1500
1501                 /* Now fill in the long header */
1502
1503                 /*
1504                  * These two first. The mac overlays the new source/dest
1505                  * network information so we MUST copy these before
1506                  * we write the network numbers !
1507                  */
1508
1509                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1510                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1511
1512                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1513                 ddp->deh_snet  = ap->s_net;
1514                 ddp->deh_sum   = 0;             /* No checksum */
1515                 /*
1516                  * Not sure about this bit...
1517                  */
1518                 /* Non routable, so force a drop if we slip up later */
1519                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1520         }
1521         skb->h.raw = skb->data;
1522
1523         return atalk_rcv(skb, dev, pt, orig_dev);
1524 freeit:
1525         kfree_skb(skb);
1526         return 0;
1527 }
1528
1529 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1530                          size_t len)
1531 {
1532         struct sock *sk = sock->sk;
1533         struct atalk_sock *at = at_sk(sk);
1534         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1535         int flags = msg->msg_flags;
1536         int loopback = 0;
1537         struct sockaddr_at local_satalk, gsat;
1538         struct sk_buff *skb;
1539         struct net_device *dev;
1540         struct ddpehdr *ddp;
1541         int size;
1542         struct atalk_route *rt;
1543         int err;
1544
1545         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1546                 return -EINVAL;
1547
1548         if (len > DDP_MAXSZ)
1549                 return -EMSGSIZE;
1550
1551         if (usat) {
1552                 if (sock_flag(sk, SOCK_ZAPPED))
1553                         if (atalk_autobind(sk) < 0)
1554                                 return -EBUSY;
1555
1556                 if (msg->msg_namelen < sizeof(*usat) ||
1557                     usat->sat_family != AF_APPLETALK)
1558                         return -EINVAL;
1559
1560                 /* netatalk doesn't implement this check */
1561                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1562                     !sock_flag(sk, SOCK_BROADCAST)) {
1563                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1564                                          "it will break before 2.2\n");
1565 #if 0
1566                         return -EPERM;
1567 #endif
1568                 }
1569         } else {
1570                 if (sk->sk_state != TCP_ESTABLISHED)
1571                         return -ENOTCONN;
1572                 usat = &local_satalk;
1573                 usat->sat_family      = AF_APPLETALK;
1574                 usat->sat_port        = at->dest_port;
1575                 usat->sat_addr.s_node = at->dest_node;
1576                 usat->sat_addr.s_net  = at->dest_net;
1577         }
1578
1579         /* Build a packet */
1580         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1581
1582         /* For headers */
1583         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1584
1585         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1586                 rt = atrtr_find(&usat->sat_addr);
1587                 dev = rt->dev;
1588         } else {
1589                 struct atalk_addr at_hint;
1590
1591                 at_hint.s_node = 0;
1592                 at_hint.s_net  = at->src_net;
1593
1594                 rt = atrtr_find(&at_hint);
1595                 dev = rt->dev;
1596         }
1597         if (!rt)
1598                 return -ENETUNREACH;
1599
1600         dev = rt->dev;
1601
1602         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1603                         sk, size, dev->name);
1604
1605         size += dev->hard_header_len;
1606         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1607         if (!skb)
1608                 return err;
1609         
1610         skb->sk = sk;
1611         skb_reserve(skb, ddp_dl->header_length);
1612         skb_reserve(skb, dev->hard_header_len);
1613         skb->dev = dev;
1614
1615         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1616
1617         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1618         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1619         ddp->deh_dnet  = usat->sat_addr.s_net;
1620         ddp->deh_snet  = at->src_net;
1621         ddp->deh_dnode = usat->sat_addr.s_node;
1622         ddp->deh_snode = at->src_node;
1623         ddp->deh_dport = usat->sat_port;
1624         ddp->deh_sport = at->src_port;
1625
1626         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1627
1628         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1629         if (err) {
1630                 kfree_skb(skb);
1631                 return -EFAULT;
1632         }
1633
1634         if (sk->sk_no_check == 1)
1635                 ddp->deh_sum = 0;
1636         else
1637                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1638
1639         /*
1640          * Loopback broadcast packets to non gateway targets (ie routes
1641          * to group we are in)
1642          */
1643         if (ddp->deh_dnode == ATADDR_BCAST &&
1644             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1645                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1646
1647                 if (skb2) {
1648                         loopback = 1;
1649                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1650                         if (aarp_send_ddp(dev, skb2,
1651                                           &usat->sat_addr, NULL) == -1)
1652                                 kfree_skb(skb2);
1653                                 /* else queued/sent above in the aarp queue */
1654                 }
1655         }
1656
1657         if (dev->flags & IFF_LOOPBACK || loopback) {
1658                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1659                 /* loop back */
1660                 skb_orphan(skb);
1661                 if (ddp->deh_dnode == ATADDR_BCAST) {
1662                         struct atalk_addr at_lo;
1663
1664                         at_lo.s_node = 0;
1665                         at_lo.s_net  = 0;
1666
1667                         rt = atrtr_find(&at_lo);
1668                         if (!rt) {
1669                                 kfree_skb(skb);
1670                                 return -ENETUNREACH;
1671                         }
1672                         dev = rt->dev;
1673                         skb->dev = dev;
1674                 }
1675                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1676         } else {
1677                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1678                 if (rt->flags & RTF_GATEWAY) {
1679                     gsat.sat_addr = rt->gateway;
1680                     usat = &gsat;
1681                 }
1682
1683                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1684                         kfree_skb(skb);
1685                 /* else queued/sent above in the aarp queue */
1686         }
1687         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1688
1689         return len;
1690 }
1691
1692 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1693                          size_t size, int flags)
1694 {
1695         struct sock *sk = sock->sk;
1696         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1697         struct ddpehdr *ddp;
1698         int copied = 0;
1699         int offset = 0;
1700         int err = 0;
1701         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1702                                                 flags & MSG_DONTWAIT, &err);
1703         if (!skb)
1704                 return err;
1705
1706         /* FIXME: use skb->cb to be able to use shared skbs */
1707         ddp = ddp_hdr(skb);
1708         copied = ntohs(ddp->deh_len_hops) & 1023;
1709
1710         if (sk->sk_type != SOCK_RAW) {
1711                 offset = sizeof(*ddp);
1712                 copied -= offset;
1713         }
1714
1715         if (copied > size) {
1716                 copied = size;
1717                 msg->msg_flags |= MSG_TRUNC;
1718         }
1719         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1720
1721         if (!err) {
1722                 if (sat) {
1723                         sat->sat_family      = AF_APPLETALK;
1724                         sat->sat_port        = ddp->deh_sport;
1725                         sat->sat_addr.s_node = ddp->deh_snode;
1726                         sat->sat_addr.s_net  = ddp->deh_snet;
1727                 }
1728                 msg->msg_namelen = sizeof(*sat);
1729         }
1730
1731         skb_free_datagram(sk, skb);     /* Free the datagram. */
1732         return err ? : copied;
1733 }
1734
1735
1736 /*
1737  * AppleTalk ioctl calls.
1738  */
1739 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1740 {
1741         int rc = -ENOIOCTLCMD;
1742         struct sock *sk = sock->sk;
1743         void __user *argp = (void __user *)arg;
1744
1745         switch (cmd) {
1746                 /* Protocol layer */
1747                 case TIOCOUTQ: {
1748                         long amount = sk->sk_sndbuf -
1749                                       atomic_read(&sk->sk_wmem_alloc);
1750
1751                         if (amount < 0)
1752                                 amount = 0;
1753                         rc = put_user(amount, (int __user *)argp);
1754                         break;
1755                 }
1756                 case TIOCINQ: {
1757                         /*
1758                          * These two are safe on a single CPU system as only
1759                          * user tasks fiddle here
1760                          */
1761                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1762                         long amount = 0;
1763
1764                         if (skb)
1765                                 amount = skb->len - sizeof(struct ddpehdr);
1766                         rc = put_user(amount, (int __user *)argp);
1767                         break;
1768                 }
1769                 case SIOCGSTAMP:
1770                         rc = sock_get_timestamp(sk, argp);
1771                         break;
1772                 /* Routing */
1773                 case SIOCADDRT:
1774                 case SIOCDELRT:
1775                         rc = -EPERM;
1776                         if (capable(CAP_NET_ADMIN))
1777                                 rc = atrtr_ioctl(cmd, argp);
1778                         break;
1779                 /* Interface */
1780                 case SIOCGIFADDR:
1781                 case SIOCSIFADDR:
1782                 case SIOCGIFBRDADDR:
1783                 case SIOCATALKDIFADDR:
1784                 case SIOCDIFADDR:
1785                 case SIOCSARP:          /* proxy AARP */
1786                 case SIOCDARP:          /* proxy AARP */
1787                         rtnl_lock();
1788                         rc = atif_ioctl(cmd, argp);
1789                         rtnl_unlock();
1790                         break;
1791         }
1792
1793         return rc;
1794 }
1795
1796
1797 #ifdef CONFIG_COMPAT
1798 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1799 {
1800         /*
1801          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1802          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1803          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1804          * here so there is no generic SIOCPROTOPRIVATE translation in the
1805          * system.
1806          */
1807         return -ENOIOCTLCMD;
1808 }
1809 #endif
1810
1811
1812 static struct net_proto_family atalk_family_ops = {
1813         .family         = PF_APPLETALK,
1814         .create         = atalk_create,
1815         .owner          = THIS_MODULE,
1816 };
1817
1818 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1819         .family         = PF_APPLETALK,
1820         .owner          = THIS_MODULE,
1821         .release        = atalk_release,
1822         .bind           = atalk_bind,
1823         .connect        = atalk_connect,
1824         .socketpair     = sock_no_socketpair,
1825         .accept         = sock_no_accept,
1826         .getname        = atalk_getname,
1827         .poll           = datagram_poll,
1828         .ioctl          = atalk_ioctl,
1829 #ifdef CONFIG_COMPAT
1830         .compat_ioctl   = atalk_compat_ioctl,
1831 #endif
1832         .listen         = sock_no_listen,
1833         .shutdown       = sock_no_shutdown,
1834         .setsockopt     = sock_no_setsockopt,
1835         .getsockopt     = sock_no_getsockopt,
1836         .sendmsg        = atalk_sendmsg,
1837         .recvmsg        = atalk_recvmsg,
1838         .mmap           = sock_no_mmap,
1839         .sendpage       = sock_no_sendpage,
1840 };
1841
1842 #include <linux/smp_lock.h>
1843 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1844
1845 static struct notifier_block ddp_notifier = {
1846         .notifier_call  = ddp_device_event,
1847 };
1848
1849 static struct packet_type ltalk_packet_type = {
1850         .type           = __constant_htons(ETH_P_LOCALTALK),
1851         .func           = ltalk_rcv,
1852 };
1853
1854 static struct packet_type ppptalk_packet_type = {
1855         .type           = __constant_htons(ETH_P_PPPTALK),
1856         .func           = atalk_rcv,
1857 };
1858
1859 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1860
1861 /* Export symbols for use by drivers when AppleTalk is a module */
1862 EXPORT_SYMBOL(aarp_send_ddp);
1863 EXPORT_SYMBOL(atrtr_get_dev);
1864 EXPORT_SYMBOL(atalk_find_dev_addr);
1865
1866 static char atalk_err_snap[] __initdata =
1867         KERN_CRIT "Unable to register DDP with SNAP.\n";
1868
1869 /* Called by proto.c on kernel start up */
1870 static int __init atalk_init(void)
1871 {
1872         int rc = proto_register(&ddp_proto, 0);
1873
1874         if (rc != 0)
1875                 goto out;
1876
1877         (void)sock_register(&atalk_family_ops);
1878         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1879         if (!ddp_dl)
1880                 printk(atalk_err_snap);
1881
1882         dev_add_pack(&ltalk_packet_type);
1883         dev_add_pack(&ppptalk_packet_type);
1884
1885         register_netdevice_notifier(&ddp_notifier);
1886         aarp_proto_init();
1887         atalk_proc_init();
1888         atalk_register_sysctl();
1889 out:
1890         return rc;
1891 }
1892 module_init(atalk_init);
1893
1894 /*
1895  * No explicit module reference count manipulation is needed in the
1896  * protocol. Socket layer sets module reference count for us
1897  * and interfaces reference counting is done
1898  * by the network device layer.
1899  *
1900  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1901  * sockets be closed from user space.
1902  */
1903 static void __exit atalk_exit(void)
1904 {
1905 #ifdef CONFIG_SYSCTL
1906         atalk_unregister_sysctl();
1907 #endif /* CONFIG_SYSCTL */
1908         atalk_proc_exit();
1909         aarp_cleanup_module();  /* General aarp clean-up. */
1910         unregister_netdevice_notifier(&ddp_notifier);
1911         dev_remove_pack(&ltalk_packet_type);
1912         dev_remove_pack(&ppptalk_packet_type);
1913         unregister_snap_client(ddp_dl);
1914         sock_unregister(PF_APPLETALK);
1915         proto_unregister(&ddp_proto);
1916 }
1917 module_exit(atalk_exit);
1918
1919 MODULE_LICENSE("GPL");
1920 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1921 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1922 MODULE_ALIAS_NETPROTO(PF_APPLETALK);