[NET]: Fix ipx/econet/appletalk/irda ioctl crashes
[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/config.h>
55 #include <linux/capability.h>
56 #include <linux/module.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/tcp_states.h>
63 #include <net/route.h>
64 #include <linux/atalk.h>
65
66 struct datalink_proto *ddp_dl, *aarp_dl;
67 static const struct proto_ops atalk_dgram_ops;
68
69 /**************************************************************************\
70 *                                                                          *
71 * Handlers for the socket list.                                            *
72 *                                                                          *
73 \**************************************************************************/
74
75 HLIST_HEAD(atalk_sockets);
76 DEFINE_RWLOCK(atalk_sockets_lock);
77
78 static inline void __atalk_insert_socket(struct sock *sk)
79 {
80         sk_add_node(sk, &atalk_sockets);
81 }
82
83 static inline void atalk_remove_socket(struct sock *sk)
84 {
85         write_lock_bh(&atalk_sockets_lock);
86         sk_del_node_init(sk);
87         write_unlock_bh(&atalk_sockets_lock);
88 }
89
90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
91                                         struct atalk_iface *atif)
92 {
93         struct sock *s;
94         struct hlist_node *node;
95
96         read_lock_bh(&atalk_sockets_lock);
97         sk_for_each(s, node, &atalk_sockets) {
98                 struct atalk_sock *at = at_sk(s);
99
100                 if (to->sat_port != at->src_port)
101                         continue;
102
103                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
104                     to->sat_addr.s_node == ATADDR_BCAST)
105                         goto found;
106
107                 if (to->sat_addr.s_net == at->src_net &&
108                     (to->sat_addr.s_node == at->src_node ||
109                      to->sat_addr.s_node == ATADDR_BCAST ||
110                      to->sat_addr.s_node == ATADDR_ANYNODE))
111                         goto found;
112
113                 /* XXXX.0 -- we got a request for this router. make sure
114                  * that the node is appropriately set. */
115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
116                     to->sat_addr.s_net != ATADDR_ANYNET &&
117                     atif->address.s_node == at->src_node) {
118                         to->sat_addr.s_node = atif->address.s_node;
119                         goto found;
120                 }
121         }
122         s = NULL;
123 found:
124         read_unlock_bh(&atalk_sockets_lock);
125         return s;
126 }
127
128 /**
129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
130  * @sk - socket to insert in the list if it is not there already
131  * @sat - address to search for
132  *
133  * Try to find a socket matching ADDR in the socket list, if found then return
134  * it. If not, insert SK into the socket list.
135  *
136  * This entire operation must execute atomically.
137  */
138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
139                                                 struct sockaddr_at *sat)
140 {
141         struct sock *s;
142         struct hlist_node *node;
143         struct atalk_sock *at;
144
145         write_lock_bh(&atalk_sockets_lock);
146         sk_for_each(s, node, &atalk_sockets) {
147                 at = at_sk(s);
148
149                 if (at->src_net == sat->sat_addr.s_net &&
150                     at->src_node == sat->sat_addr.s_node &&
151                     at->src_port == sat->sat_port)
152                         goto found;
153         }
154         s = NULL;
155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
156 found:
157         write_unlock_bh(&atalk_sockets_lock);
158         return s;
159 }
160
161 static void atalk_destroy_timer(unsigned long data)
162 {
163         struct sock *sk = (struct sock *)data;
164
165         if (atomic_read(&sk->sk_wmem_alloc) ||
166             atomic_read(&sk->sk_rmem_alloc)) {
167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
168                 add_timer(&sk->sk_timer);
169         } else
170                 sock_put(sk);
171 }
172
173 static inline void atalk_destroy_socket(struct sock *sk)
174 {
175         atalk_remove_socket(sk);
176         skb_queue_purge(&sk->sk_receive_queue);
177
178         if (atomic_read(&sk->sk_wmem_alloc) ||
179             atomic_read(&sk->sk_rmem_alloc)) {
180                 init_timer(&sk->sk_timer);
181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
182                 sk->sk_timer.function   = atalk_destroy_timer;
183                 sk->sk_timer.data       = (unsigned long)sk;
184                 add_timer(&sk->sk_timer);
185         } else
186                 sock_put(sk);
187 }
188
189 /**************************************************************************\
190 *                                                                          *
191 * Routing tables for the AppleTalk socket layer.                           *
192 *                                                                          *
193 \**************************************************************************/
194
195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
196 struct atalk_route *atalk_routes;
197 DEFINE_RWLOCK(atalk_routes_lock);
198
199 struct atalk_iface *atalk_interfaces;
200 DEFINE_RWLOCK(atalk_interfaces_lock);
201
202 /* For probing devices or in a routerless network */
203 struct atalk_route atrtr_default;
204
205 /* AppleTalk interface control */
206 /*
207  * Drop a device. Doesn't drop any of its routes - that is the caller's
208  * problem. Called when we down the interface or delete the address.
209  */
210 static void atif_drop_device(struct net_device *dev)
211 {
212         struct atalk_iface **iface = &atalk_interfaces;
213         struct atalk_iface *tmp;
214
215         write_lock_bh(&atalk_interfaces_lock);
216         while ((tmp = *iface) != NULL) {
217                 if (tmp->dev == dev) {
218                         *iface = tmp->next;
219                         dev_put(dev);
220                         kfree(tmp);
221                         dev->atalk_ptr = NULL;
222                 } else
223                         iface = &tmp->next;
224         }
225         write_unlock_bh(&atalk_interfaces_lock);
226 }
227
228 static struct atalk_iface *atif_add_device(struct net_device *dev,
229                                            struct atalk_addr *sa)
230 {
231         struct atalk_iface *iface = 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(__be16 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         dev_hold(devhint);
577         rt->dev     = devhint;
578         rt->flags   = r->rt_flags;
579         rt->gateway = ga->sat_addr;
580
581         retval = 0;
582 out_unlock:
583         write_unlock_bh(&atalk_routes_lock);
584 out:
585         return retval;
586 }
587
588 /* Delete a route. Find it and discard it */
589 static int atrtr_delete(struct atalk_addr * addr)
590 {
591         struct atalk_route **r = &atalk_routes;
592         int retval = 0;
593         struct atalk_route *tmp;
594
595         write_lock_bh(&atalk_routes_lock);
596         while ((tmp = *r) != NULL) {
597                 if (tmp->target.s_net == addr->s_net &&
598                     (!(tmp->flags&RTF_GATEWAY) ||
599                      tmp->target.s_node == addr->s_node)) {
600                         *r = tmp->next;
601                         dev_put(tmp->dev);
602                         kfree(tmp);
603                         goto out;
604                 }
605                 r = &tmp->next;
606         }
607         retval = -ENOENT;
608 out:
609         write_unlock_bh(&atalk_routes_lock);
610         return retval;
611 }
612
613 /*
614  * Called when a device is downed. Just throw away any routes
615  * via it.
616  */
617 static void atrtr_device_down(struct net_device *dev)
618 {
619         struct atalk_route **r = &atalk_routes;
620         struct atalk_route *tmp;
621
622         write_lock_bh(&atalk_routes_lock);
623         while ((tmp = *r) != NULL) {
624                 if (tmp->dev == dev) {
625                         *r = tmp->next;
626                         dev_put(dev);
627                         kfree(tmp);
628                 } else
629                         r = &tmp->next;
630         }
631         write_unlock_bh(&atalk_routes_lock);
632
633         if (atrtr_default.dev == dev)
634                 atrtr_set_default(NULL);
635 }
636
637 /* Actually down the interface */
638 static inline void atalk_dev_down(struct net_device *dev)
639 {
640         atrtr_device_down(dev); /* Remove all routes for the device */
641         aarp_device_down(dev);  /* Remove AARP entries for the device */
642         atif_drop_device(dev);  /* Remove the device */
643 }
644
645 /*
646  * A device event has occurred. Watch for devices going down and
647  * delete our use of them (iface and route).
648  */
649 static int ddp_device_event(struct notifier_block *this, unsigned long event,
650                             void *ptr)
651 {
652         if (event == NETDEV_DOWN)
653                 /* Discard any use of this */
654                 atalk_dev_down(ptr);
655
656         return NOTIFY_DONE;
657 }
658
659 /* ioctl calls. Shouldn't even need touching */
660 /* Device configuration ioctl calls */
661 static int atif_ioctl(int cmd, void __user *arg)
662 {
663         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
664         struct ifreq atreq;
665         struct atalk_netrange *nr;
666         struct sockaddr_at *sa;
667         struct net_device *dev;
668         struct atalk_iface *atif;
669         int ct;
670         int limit;
671         struct rtentry rtdef;
672         int add_route;
673
674         if (copy_from_user(&atreq, arg, sizeof(atreq)))
675                 return -EFAULT;
676
677         dev = __dev_get_by_name(atreq.ifr_name);
678         if (!dev)
679                 return -ENODEV;
680
681         sa = (struct sockaddr_at *)&atreq.ifr_addr;
682         atif = atalk_find_dev(dev);
683
684         switch (cmd) {
685                 case SIOCSIFADDR:
686                         if (!capable(CAP_NET_ADMIN))
687                                 return -EPERM;
688                         if (sa->sat_family != AF_APPLETALK)
689                                 return -EINVAL;
690                         if (dev->type != ARPHRD_ETHER &&
691                             dev->type != ARPHRD_LOOPBACK &&
692                             dev->type != ARPHRD_LOCALTLK &&
693                             dev->type != ARPHRD_PPP)
694                                 return -EPROTONOSUPPORT;
695
696                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
697                         add_route = 1;
698
699                         /*
700                          * if this is a point-to-point iface, and we already
701                          * have an iface for this AppleTalk address, then we
702                          * should not add a route
703                          */
704                         if ((dev->flags & IFF_POINTOPOINT) &&
705                             atalk_find_interface(sa->sat_addr.s_net,
706                                                  sa->sat_addr.s_node)) {
707                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
708                                                   "interface added with "
709                                                   "existing address\n");
710                                 add_route = 0;
711                         }
712                         
713                         /*
714                          * Phase 1 is fine on LocalTalk but we don't do
715                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
716                          */
717                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
718                                 return -EPROTONOSUPPORT;
719                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
720                             sa->sat_addr.s_node == 254)
721                                 return -EINVAL;
722                         if (atif) {
723                                 /* Already setting address */
724                                 if (atif->status & ATIF_PROBE)
725                                         return -EBUSY;
726
727                                 atif->address.s_net  = sa->sat_addr.s_net;
728                                 atif->address.s_node = sa->sat_addr.s_node;
729                                 atrtr_device_down(dev); /* Flush old routes */
730                         } else {
731                                 atif = atif_add_device(dev, &sa->sat_addr);
732                                 if (!atif)
733                                         return -ENOMEM;
734                         }
735                         atif->nets = *nr;
736
737                         /*
738                          * Check if the chosen address is used. If so we
739                          * error and atalkd will try another.
740                          */
741
742                         if (!(dev->flags & IFF_LOOPBACK) &&
743                             !(dev->flags & IFF_POINTOPOINT) &&
744                             atif_probe_device(atif) < 0) {
745                                 atif_drop_device(dev);
746                                 return -EADDRINUSE;
747                         }
748
749                         /* Hey it worked - add the direct routes */
750                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
751                         sa->sat_family = AF_APPLETALK;
752                         sa->sat_addr.s_net  = atif->address.s_net;
753                         sa->sat_addr.s_node = atif->address.s_node;
754                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
755                         rtdef.rt_flags = RTF_UP;
756                         sa->sat_family = AF_APPLETALK;
757                         sa->sat_addr.s_node = ATADDR_ANYNODE;
758                         if (dev->flags & IFF_LOOPBACK ||
759                             dev->flags & IFF_POINTOPOINT)
760                                 rtdef.rt_flags |= RTF_HOST;
761
762                         /* Routerless initial state */
763                         if (nr->nr_firstnet == htons(0) &&
764                             nr->nr_lastnet == htons(0xFFFE)) {
765                                 sa->sat_addr.s_net = atif->address.s_net;
766                                 atrtr_create(&rtdef, dev);
767                                 atrtr_set_default(dev);
768                         } else {
769                                 limit = ntohs(nr->nr_lastnet);
770                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
771                                         printk(KERN_WARNING "Too many routes/"
772                                                             "iface.\n");
773                                         return -EINVAL;
774                                 }
775                                 if (add_route)
776                                         for (ct = ntohs(nr->nr_firstnet);
777                                              ct <= limit; ct++) {
778                                                 sa->sat_addr.s_net = htons(ct);
779                                                 atrtr_create(&rtdef, dev);
780                                         }
781                         }
782                         dev_mc_add(dev, aarp_mcast, 6, 1);
783                         return 0;
784
785                 case SIOCGIFADDR:
786                         if (!atif)
787                                 return -EADDRNOTAVAIL;
788
789                         sa->sat_family = AF_APPLETALK;
790                         sa->sat_addr = atif->address;
791                         break;
792
793                 case SIOCGIFBRDADDR:
794                         if (!atif)
795                                 return -EADDRNOTAVAIL;
796
797                         sa->sat_family = AF_APPLETALK;
798                         sa->sat_addr.s_net = atif->address.s_net;
799                         sa->sat_addr.s_node = ATADDR_BCAST;
800                         break;
801
802                 case SIOCATALKDIFADDR:
803                 case SIOCDIFADDR:
804                         if (!capable(CAP_NET_ADMIN))
805                                 return -EPERM;
806                         if (sa->sat_family != AF_APPLETALK)
807                                 return -EINVAL;
808                         atalk_dev_down(dev);
809                         break;                  
810
811                 case SIOCSARP:
812                         if (!capable(CAP_NET_ADMIN))
813                                 return -EPERM;
814                         if (sa->sat_family != AF_APPLETALK)
815                                 return -EINVAL;
816                         if (!atif)
817                                 return -EADDRNOTAVAIL;
818
819                         /*
820                          * for now, we only support proxy AARP on ELAP;
821                          * we should be able to do it for LocalTalk, too.
822                          */
823                         if (dev->type != ARPHRD_ETHER)
824                                 return -EPROTONOSUPPORT;
825
826                         /*
827                          * atif points to the current interface on this network;
828                          * we aren't concerned about its current status (at
829                          * least for now), but it has all the settings about
830                          * the network we're going to probe. Consequently, it
831                          * must exist.
832                          */
833                         if (!atif)
834                                 return -EADDRNOTAVAIL;
835
836                         nr = (struct atalk_netrange *)&(atif->nets);
837                         /*
838                          * Phase 1 is fine on Localtalk but we don't do
839                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
840                          */
841                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
842                                 return -EPROTONOSUPPORT;
843
844                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
845                             sa->sat_addr.s_node == 254)
846                                 return -EINVAL;
847
848                         /*
849                          * Check if the chosen address is used. If so we
850                          * error and ATCP will try another.
851                          */
852                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
853                                 return -EADDRINUSE;
854                         
855                         /*
856                          * We now have an address on the local network, and
857                          * the AARP code will defend it for us until we take it
858                          * down. We don't set up any routes right now, because
859                          * ATCP will install them manually via SIOCADDRT.
860                          */
861                         break;
862
863                 case SIOCDARP:
864                         if (!capable(CAP_NET_ADMIN))
865                                 return -EPERM;
866                         if (sa->sat_family != AF_APPLETALK)
867                                 return -EINVAL;
868                         if (!atif)
869                                 return -EADDRNOTAVAIL;
870
871                         /* give to aarp module to remove proxy entry */
872                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
873                         return 0;
874         }
875
876         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
877 }
878
879 /* Routing ioctl() calls */
880 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
881 {
882         struct rtentry rt;
883
884         if (copy_from_user(&rt, arg, sizeof(rt)))
885                 return -EFAULT;
886
887         switch (cmd) {
888                 case SIOCDELRT:
889                         if (rt.rt_dst.sa_family != AF_APPLETALK)
890                                 return -EINVAL;
891                         return atrtr_delete(&((struct sockaddr_at *)
892                                                 &rt.rt_dst)->sat_addr);
893
894                 case SIOCADDRT: {
895                         struct net_device *dev = NULL;
896                         if (rt.rt_dev) {
897                                 char name[IFNAMSIZ];
898                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
899                                         return -EFAULT;
900                                 name[IFNAMSIZ-1] = '\0';
901                                 dev = __dev_get_by_name(name);
902                                 if (!dev)
903                                         return -ENODEV;
904                         }                       
905                         return atrtr_create(&rt, dev);
906                 }
907         }
908         return -EINVAL;
909 }
910
911 /**************************************************************************\
912 *                                                                          *
913 * Handling for system calls applied via the various interfaces to an       *
914 * AppleTalk socket object.                                                 *
915 *                                                                          *
916 \**************************************************************************/
917
918 /*
919  * Checksum: This is 'optional'. It's quite likely also a good
920  * candidate for assembler hackery 8)
921  */
922 static unsigned long atalk_sum_partial(const unsigned char *data, 
923                                        int len, unsigned long sum)
924 {
925         /* This ought to be unwrapped neatly. I'll trust gcc for now */
926         while (len--) {
927                 sum += *data;
928                 sum <<= 1;
929                 if (sum & 0x10000) {
930                         sum++;
931                         sum &= 0xffff;
932                 }
933                 data++;
934         }
935         return sum;
936 }
937
938 /*  Checksum skb data --  similar to skb_checksum  */
939 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
940                                    int len, unsigned long sum)
941 {
942         int start = skb_headlen(skb);
943         int i, copy;
944
945         /* checksum stuff in header space */
946         if ( (copy = start - offset) > 0) {
947                 if (copy > len)
948                         copy = len;
949                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
950                 if ( (len -= copy) == 0) 
951                         return sum;
952
953                 offset += copy;
954         }
955
956         /* checksum stuff in frags */
957         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
958                 int end;
959
960                 BUG_TRAP(start <= offset + len);
961
962                 end = start + skb_shinfo(skb)->frags[i].size;
963                 if ((copy = end - offset) > 0) {
964                         u8 *vaddr;
965                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
966
967                         if (copy > len)
968                                 copy = len;
969                         vaddr = kmap_skb_frag(frag);
970                         sum = atalk_sum_partial(vaddr + frag->page_offset +
971                                                   offset - start, copy, sum);
972                         kunmap_skb_frag(vaddr);
973
974                         if (!(len -= copy))
975                                 return sum;
976                         offset += copy;
977                 }
978                 start = end;
979         }
980
981         if (skb_shinfo(skb)->frag_list) {
982                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
983
984                 for (; list; list = list->next) {
985                         int end;
986
987                         BUG_TRAP(start <= offset + len);
988
989                         end = start + list->len;
990                         if ((copy = end - offset) > 0) {
991                                 if (copy > len)
992                                         copy = len;
993                                 sum = atalk_sum_skb(list, offset - start,
994                                                     copy, sum);
995                                 if ((len -= copy) == 0)
996                                         return sum;
997                                 offset += copy;
998                         }
999                         start = end;
1000                 }
1001         }
1002
1003         BUG_ON(len > 0);
1004
1005         return sum;
1006 }
1007
1008 static unsigned short atalk_checksum(const struct sk_buff *skb, int len)
1009 {
1010         unsigned long sum;
1011
1012         /* skip header 4 bytes */
1013         sum = atalk_sum_skb(skb, 4, len-4, 0);
1014
1015         /* Use 0xFFFF for 0. 0 itself means none */
1016         return sum ? htons((unsigned short)sum) : 0xFFFF;
1017 }
1018
1019 static struct proto ddp_proto = {
1020         .name     = "DDP",
1021         .owner    = THIS_MODULE,
1022         .obj_size = sizeof(struct atalk_sock),
1023 };
1024
1025 /*
1026  * Create a socket. Initialise the socket, blank the addresses
1027  * set the state.
1028  */
1029 static int atalk_create(struct socket *sock, int protocol)
1030 {
1031         struct sock *sk;
1032         int rc = -ESOCKTNOSUPPORT;
1033
1034         /*
1035          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1036          * and gives you the full ELAP frame. Should be handy for CAP 8) 
1037          */
1038         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1039                 goto out;
1040         rc = -ENOMEM;
1041         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1042         if (!sk)
1043                 goto out;
1044         rc = 0;
1045         sock->ops = &atalk_dgram_ops;
1046         sock_init_data(sock, sk);
1047
1048         /* Checksums on by default */
1049         sock_set_flag(sk, SOCK_ZAPPED);
1050 out:
1051         return rc;
1052 }
1053
1054 /* Free a socket. No work needed */
1055 static int atalk_release(struct socket *sock)
1056 {
1057         struct sock *sk = sock->sk;
1058
1059         if (sk) {
1060                 sock_orphan(sk);
1061                 sock->sk = NULL;
1062                 atalk_destroy_socket(sk);
1063         }
1064         return 0;
1065 }
1066
1067 /**
1068  * atalk_pick_and_bind_port - Pick a source port when one is not given
1069  * @sk - socket to insert into the tables
1070  * @sat - address to search for
1071  *
1072  * Pick a source port when one is not given. If we can find a suitable free
1073  * one, we insert the socket into the tables using it.
1074  *
1075  * This whole operation must be atomic.
1076  */
1077 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1078 {
1079         int retval;
1080
1081         write_lock_bh(&atalk_sockets_lock);
1082
1083         for (sat->sat_port = ATPORT_RESERVED;
1084              sat->sat_port < ATPORT_LAST;
1085              sat->sat_port++) {
1086                 struct sock *s;
1087                 struct hlist_node *node;
1088
1089                 sk_for_each(s, node, &atalk_sockets) {
1090                         struct atalk_sock *at = at_sk(s);
1091
1092                         if (at->src_net == sat->sat_addr.s_net &&
1093                             at->src_node == sat->sat_addr.s_node &&
1094                             at->src_port == sat->sat_port)
1095                                 goto try_next_port;
1096                 }
1097
1098                 /* Wheee, it's free, assign and insert. */
1099                 __atalk_insert_socket(sk);
1100                 at_sk(sk)->src_port = sat->sat_port;
1101                 retval = 0;
1102                 goto out;
1103
1104 try_next_port:;
1105         }
1106
1107         retval = -EBUSY;
1108 out:
1109         write_unlock_bh(&atalk_sockets_lock);
1110         return retval;
1111 }
1112
1113 static int atalk_autobind(struct sock *sk)
1114 {
1115         struct atalk_sock *at = at_sk(sk);
1116         struct sockaddr_at sat;
1117         struct atalk_addr *ap = atalk_find_primary();
1118         int n = -EADDRNOTAVAIL;
1119
1120         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1121                 goto out;
1122
1123         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1124         at->src_node = sat.sat_addr.s_node = ap->s_node;
1125
1126         n = atalk_pick_and_bind_port(sk, &sat);
1127         if (!n)
1128                 sock_reset_flag(sk, SOCK_ZAPPED);
1129 out:
1130         return n;
1131 }
1132
1133 /* Set the address 'our end' of the connection */
1134 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1135 {
1136         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1137         struct sock *sk = sock->sk;
1138         struct atalk_sock *at = at_sk(sk);
1139
1140         if (!sock_flag(sk, SOCK_ZAPPED) ||
1141             addr_len != sizeof(struct sockaddr_at))
1142                 return -EINVAL;
1143
1144         if (addr->sat_family != AF_APPLETALK)
1145                 return -EAFNOSUPPORT;
1146
1147         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1148                 struct atalk_addr *ap = atalk_find_primary();
1149
1150                 if (!ap)
1151                         return -EADDRNOTAVAIL;
1152
1153                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1154                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1155         } else {
1156                 if (!atalk_find_interface(addr->sat_addr.s_net,
1157                                           addr->sat_addr.s_node))
1158                         return -EADDRNOTAVAIL;
1159
1160                 at->src_net  = addr->sat_addr.s_net;
1161                 at->src_node = addr->sat_addr.s_node;
1162         }
1163
1164         if (addr->sat_port == ATADDR_ANYPORT) {
1165                 int n = atalk_pick_and_bind_port(sk, addr);
1166
1167                 if (n < 0)
1168                         return n;
1169         } else {
1170                 at->src_port = addr->sat_port;
1171
1172                 if (atalk_find_or_insert_socket(sk, addr))
1173                         return -EADDRINUSE;
1174         }
1175
1176         sock_reset_flag(sk, SOCK_ZAPPED);
1177         return 0;
1178 }
1179
1180 /* Set the address we talk to */
1181 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1182                          int addr_len, int flags)
1183 {
1184         struct sock *sk = sock->sk;
1185         struct atalk_sock *at = at_sk(sk);
1186         struct sockaddr_at *addr;
1187
1188         sk->sk_state   = TCP_CLOSE;
1189         sock->state = SS_UNCONNECTED;
1190
1191         if (addr_len != sizeof(*addr))
1192                 return -EINVAL;
1193
1194         addr = (struct sockaddr_at *)uaddr;
1195
1196         if (addr->sat_family != AF_APPLETALK)
1197                 return -EAFNOSUPPORT;
1198
1199         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1200             !sock_flag(sk, SOCK_BROADCAST)) {
1201 #if 1   
1202                 printk(KERN_WARNING "%s is broken and did not set "
1203                                     "SO_BROADCAST. It will break when 2.2 is "
1204                                     "released.\n",
1205                         current->comm);
1206 #else
1207                 return -EACCES;
1208 #endif                  
1209         }
1210
1211         if (sock_flag(sk, SOCK_ZAPPED))
1212                 if (atalk_autobind(sk) < 0)
1213                         return -EBUSY;
1214
1215         if (!atrtr_get_dev(&addr->sat_addr))
1216                 return -ENETUNREACH;
1217
1218         at->dest_port = addr->sat_port;
1219         at->dest_net  = addr->sat_addr.s_net;
1220         at->dest_node = addr->sat_addr.s_node;
1221
1222         sock->state  = SS_CONNECTED;
1223         sk->sk_state = TCP_ESTABLISHED;
1224         return 0;
1225 }
1226
1227 /*
1228  * Find the name of an AppleTalk socket. Just copy the right
1229  * fields into the sockaddr.
1230  */
1231 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1232                          int *uaddr_len, int peer)
1233 {
1234         struct sockaddr_at sat;
1235         struct sock *sk = sock->sk;
1236         struct atalk_sock *at = at_sk(sk);
1237
1238         if (sock_flag(sk, SOCK_ZAPPED))
1239                 if (atalk_autobind(sk) < 0)
1240                         return -ENOBUFS;
1241
1242         *uaddr_len = sizeof(struct sockaddr_at);
1243
1244         if (peer) {
1245                 if (sk->sk_state != TCP_ESTABLISHED)
1246                         return -ENOTCONN;
1247
1248                 sat.sat_addr.s_net  = at->dest_net;
1249                 sat.sat_addr.s_node = at->dest_node;
1250                 sat.sat_port        = at->dest_port;
1251         } else {
1252                 sat.sat_addr.s_net  = at->src_net;
1253                 sat.sat_addr.s_node = at->src_node;
1254                 sat.sat_port        = at->src_port;
1255         }
1256
1257         sat.sat_family = AF_APPLETALK;
1258         memcpy(uaddr, &sat, sizeof(sat));
1259         return 0;
1260 }
1261
1262 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1263 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1264 {
1265         return skb->data[12] == 22;
1266 }
1267
1268 static int handle_ip_over_ddp(struct sk_buff *skb)
1269 {
1270         struct net_device *dev = __dev_get_by_name("ipddp0");
1271         struct net_device_stats *stats;
1272
1273         /* This needs to be able to handle ipddp"N" devices */
1274         if (!dev)
1275                 return -ENODEV;
1276
1277         skb->protocol = htons(ETH_P_IP);
1278         skb_pull(skb, 13);
1279         skb->dev   = dev;
1280         skb->h.raw = skb->data;
1281
1282         stats = dev->priv;
1283         stats->rx_packets++;
1284         stats->rx_bytes += skb->len + 13;
1285         netif_rx(skb);  /* Send the SKB up to a higher place. */
1286         return 0;
1287 }
1288 #else
1289 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1290 #define is_ip_over_ddp(skb) 0
1291 #define handle_ip_over_ddp(skb) 0
1292 #endif
1293
1294 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1295                                struct ddpehdr *ddp, struct ddpebits *ddphv,
1296                                int origlen)
1297 {
1298         struct atalk_route *rt;
1299         struct atalk_addr ta;
1300
1301         /*
1302          * Don't route multicast, etc., packets, or packets sent to "this
1303          * network" 
1304          */
1305         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1306                 /*
1307                  * FIXME:
1308                  *
1309                  * Can it ever happen that a packet is from a PPP iface and
1310                  * needs to be broadcast onto the default network?
1311                  */
1312                 if (dev->type == ARPHRD_PPP)
1313                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1314                                           "packet received from PPP iface\n");
1315                 goto free_it;
1316         }
1317
1318         ta.s_net  = ddp->deh_dnet;
1319         ta.s_node = ddp->deh_dnode;
1320
1321         /* Route the packet */
1322         rt = atrtr_find(&ta);
1323         if (!rt || ddphv->deh_hops == DDP_MAXHOPS)
1324                 goto free_it;
1325         /* FIXME: use skb->cb to be able to use shared skbs */
1326         ddphv->deh_hops++;
1327
1328         /*
1329          * Route goes through another gateway, so set the target to the
1330          * gateway instead.
1331          */
1332
1333         if (rt->flags & RTF_GATEWAY) {
1334                 ta.s_net  = rt->gateway.s_net;
1335                 ta.s_node = rt->gateway.s_node;
1336         }
1337
1338         /* Fix up skb->len field */
1339         skb_trim(skb, min_t(unsigned int, origlen,
1340                             (rt->dev->hard_header_len +
1341                              ddp_dl->header_length + ddphv->deh_len)));
1342
1343         /* Mend the byte order */
1344         /* FIXME: use skb->cb to be able to use shared skbs */
1345         *((__u16 *)ddp) = ntohs(*((__u16 *)ddphv));
1346
1347         /*
1348          * Send the buffer onwards
1349          *
1350          * Now we must always be careful. If it's come from LocalTalk to
1351          * EtherTalk it might not fit
1352          *
1353          * Order matters here: If a packet has to be copied to make a new
1354          * headroom (rare hopefully) then it won't need unsharing.
1355          *
1356          * Note. ddp-> becomes invalid at the realloc.
1357          */
1358         if (skb_headroom(skb) < 22) {
1359                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1360                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1361                 kfree_skb(skb);
1362                 if (!nskb) 
1363                         goto out;
1364                 skb = nskb;
1365         } else
1366                 skb = skb_unshare(skb, GFP_ATOMIC);
1367         
1368         /*
1369          * If the buffer didn't vanish into the lack of space bitbucket we can
1370          * send it.
1371          */
1372         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1373                 goto free_it;
1374 out:
1375         return;
1376 free_it:
1377         kfree_skb(skb);
1378 }
1379
1380 /**
1381  *      atalk_rcv - Receive a packet (in skb) from device dev
1382  *      @skb - packet received
1383  *      @dev - network device where the packet comes from
1384  *      @pt - packet type
1385  *
1386  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1387  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1388  *      header, skb->len is the DDP length. The physical headers have been
1389  *      extracted. PPP should probably pass frames marked as for this layer.
1390  *      [ie ARPHRD_ETHERTALK]
1391  */
1392 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1393                      struct packet_type *pt, struct net_device *orig_dev)
1394 {
1395         struct ddpehdr *ddp;
1396         struct sock *sock;
1397         struct atalk_iface *atif;
1398         struct sockaddr_at tosat;
1399         int origlen;
1400         struct ddpebits ddphv;
1401
1402         /* Don't mangle buffer if shared */
1403         if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
1404                 goto out;
1405                 
1406         /* Size check and make sure header is contiguous */
1407         if (!pskb_may_pull(skb, sizeof(*ddp)))
1408                 goto freeit;
1409
1410         ddp = ddp_hdr(skb);
1411
1412         /*
1413          *      Fix up the length field [Ok this is horrible but otherwise
1414          *      I end up with unions of bit fields and messy bit field order
1415          *      compiler/endian dependencies..]
1416          */
1417         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1418
1419         /* Trim buffer in case of stray trailing data */
1420         origlen = skb->len;
1421         skb_trim(skb, min_t(unsigned int, skb->len, ddphv.deh_len));
1422
1423         /*
1424          * Size check to see if ddp->deh_len was crap
1425          * (Otherwise we'll detonate most spectacularly
1426          * in the middle of recvmsg()).
1427          */
1428         if (skb->len < sizeof(*ddp))
1429                 goto freeit;
1430
1431         /*
1432          * Any checksums. Note we don't do htons() on this == is assumed to be
1433          * valid for net byte orders all over the networking code...
1434          */
1435         if (ddp->deh_sum &&
1436             atalk_checksum(skb, ddphv.deh_len) != ddp->deh_sum)
1437                 /* Not a valid AppleTalk frame - dustbin time */
1438                 goto freeit;
1439
1440         /* Check the packet is aimed at us */
1441         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1442                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1443         else
1444                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1445
1446         if (!atif) {
1447                 /* Not ours, so we route the packet via the correct
1448                  * AppleTalk iface
1449                  */
1450                 atalk_route_packet(skb, dev, ddp, &ddphv, origlen);
1451                 goto out;
1452         }
1453
1454         /* if IP over DDP is not selected this code will be optimized out */
1455         if (is_ip_over_ddp(skb))
1456                 return handle_ip_over_ddp(skb);
1457         /*
1458          * Which socket - atalk_search_socket() looks for a *full match*
1459          * of the <net, node, port> tuple.
1460          */
1461         tosat.sat_addr.s_net  = ddp->deh_dnet;
1462         tosat.sat_addr.s_node = ddp->deh_dnode;
1463         tosat.sat_port        = ddp->deh_dport;
1464
1465         sock = atalk_search_socket(&tosat, atif);
1466         if (!sock) /* But not one of our sockets */
1467                 goto freeit;
1468
1469         /* Queue packet (standard) */
1470         skb->sk = sock;
1471
1472         if (sock_queue_rcv_skb(sock, skb) < 0)
1473                 goto freeit;
1474 out:
1475         return 0;
1476 freeit:
1477         kfree_skb(skb);
1478         goto out;
1479 }
1480
1481 /*
1482  * Receive a LocalTalk frame. We make some demands on the caller here.
1483  * Caller must provide enough headroom on the packet to pull the short
1484  * header and append a long one.
1485  */
1486 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1487                      struct packet_type *pt, struct net_device *orig_dev)
1488 {
1489         /* Expand any short form frames */
1490         if (skb->mac.raw[2] == 1) {
1491                 struct ddpehdr *ddp;
1492                 /* Find our address */
1493                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1494
1495                 if (!ap || skb->len < sizeof(struct ddpshdr))
1496                         goto freeit;
1497
1498                 /* Don't mangle buffer if shared */
1499                 if (!(skb = skb_share_check(skb, GFP_ATOMIC))) 
1500                         return 0;
1501
1502                 /*
1503                  * The push leaves us with a ddephdr not an shdr, and
1504                  * handily the port bytes in the right place preset.
1505                  */
1506                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1507
1508                 /* Now fill in the long header */
1509
1510                 /*
1511                  * These two first. The mac overlays the new source/dest
1512                  * network information so we MUST copy these before
1513                  * we write the network numbers !
1514                  */
1515
1516                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1517                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1518
1519                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1520                 ddp->deh_snet  = ap->s_net;
1521                 ddp->deh_sum   = 0;             /* No checksum */
1522                 /*
1523                  * Not sure about this bit...
1524                  */
1525                 ddp->deh_len   = skb->len;
1526                 ddp->deh_hops  = DDP_MAXHOPS;   /* Non routable, so force a drop
1527                                                    if we slip up later */
1528                 /* Mend the byte order */
1529                 *((__u16 *)ddp) = htons(*((__u16 *)ddp));
1530         }
1531         skb->h.raw = skb->data;
1532
1533         return atalk_rcv(skb, dev, pt, orig_dev);
1534 freeit:
1535         kfree_skb(skb);
1536         return 0;
1537 }
1538
1539 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1540                          size_t len)
1541 {
1542         struct sock *sk = sock->sk;
1543         struct atalk_sock *at = at_sk(sk);
1544         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1545         int flags = msg->msg_flags;
1546         int loopback = 0;
1547         struct sockaddr_at local_satalk, gsat;
1548         struct sk_buff *skb;
1549         struct net_device *dev;
1550         struct ddpehdr *ddp;
1551         int size;
1552         struct atalk_route *rt;
1553         int err;
1554
1555         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1556                 return -EINVAL;
1557
1558         if (len > DDP_MAXSZ)
1559                 return -EMSGSIZE;
1560
1561         if (usat) {
1562                 if (sock_flag(sk, SOCK_ZAPPED))
1563                         if (atalk_autobind(sk) < 0)
1564                                 return -EBUSY;
1565
1566                 if (msg->msg_namelen < sizeof(*usat) ||
1567                     usat->sat_family != AF_APPLETALK)
1568                         return -EINVAL;
1569
1570                 /* netatalk doesn't implement this check */
1571                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1572                     !sock_flag(sk, SOCK_BROADCAST)) {
1573                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1574                                          "it will break before 2.2\n");
1575 #if 0
1576                         return -EPERM;
1577 #endif
1578                 }
1579         } else {
1580                 if (sk->sk_state != TCP_ESTABLISHED)
1581                         return -ENOTCONN;
1582                 usat = &local_satalk;
1583                 usat->sat_family      = AF_APPLETALK;
1584                 usat->sat_port        = at->dest_port;
1585                 usat->sat_addr.s_node = at->dest_node;
1586                 usat->sat_addr.s_net  = at->dest_net;
1587         }
1588
1589         /* Build a packet */
1590         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1591
1592         /* For headers */
1593         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1594
1595         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1596                 rt = atrtr_find(&usat->sat_addr);
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                 dev = rt->dev;
1606         }
1607         if (!rt)
1608                 return -ENETUNREACH;
1609
1610         dev = rt->dev;
1611
1612         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1613                         sk, size, dev->name);
1614
1615         size += dev->hard_header_len;
1616         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1617         if (!skb)
1618                 return err;
1619         
1620         skb->sk = sk;
1621         skb_reserve(skb, ddp_dl->header_length);
1622         skb_reserve(skb, dev->hard_header_len);
1623         skb->dev = dev;
1624
1625         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1626
1627         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1628         ddp->deh_pad  = 0;
1629         ddp->deh_hops = 0;
1630         ddp->deh_len  = len + sizeof(*ddp);
1631         /*
1632          * Fix up the length field [Ok this is horrible but otherwise
1633          * I end up with unions of bit fields and messy bit field order
1634          * compiler/endian dependencies..
1635          */
1636         *((__u16 *)ddp) = ntohs(*((__u16 *)ddp));
1637
1638         ddp->deh_dnet  = usat->sat_addr.s_net;
1639         ddp->deh_snet  = at->src_net;
1640         ddp->deh_dnode = usat->sat_addr.s_node;
1641         ddp->deh_snode = at->src_node;
1642         ddp->deh_dport = usat->sat_port;
1643         ddp->deh_sport = at->src_port;
1644
1645         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1646
1647         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1648         if (err) {
1649                 kfree_skb(skb);
1650                 return -EFAULT;
1651         }
1652
1653         if (sk->sk_no_check == 1)
1654                 ddp->deh_sum = 0;
1655         else
1656                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1657
1658         /*
1659          * Loopback broadcast packets to non gateway targets (ie routes
1660          * to group we are in)
1661          */
1662         if (ddp->deh_dnode == ATADDR_BCAST &&
1663             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1664                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1665
1666                 if (skb2) {
1667                         loopback = 1;
1668                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1669                         if (aarp_send_ddp(dev, skb2,
1670                                           &usat->sat_addr, NULL) == -1)
1671                                 kfree_skb(skb2);
1672                                 /* else queued/sent above in the aarp queue */
1673                 }
1674         }
1675
1676         if (dev->flags & IFF_LOOPBACK || loopback) {
1677                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1678                 /* loop back */
1679                 skb_orphan(skb);
1680                 if (ddp->deh_dnode == ATADDR_BCAST) {
1681                         struct atalk_addr at_lo;
1682
1683                         at_lo.s_node = 0;
1684                         at_lo.s_net  = 0;
1685
1686                         rt = atrtr_find(&at_lo);
1687                         if (!rt) {
1688                                 kfree_skb(skb);
1689                                 return -ENETUNREACH;
1690                         }
1691                         dev = rt->dev;
1692                         skb->dev = dev;
1693                 }
1694                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1695         } else {
1696                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1697                 if (rt->flags & RTF_GATEWAY) {
1698                     gsat.sat_addr = rt->gateway;
1699                     usat = &gsat;
1700                 }
1701
1702                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1703                         kfree_skb(skb);
1704                 /* else queued/sent above in the aarp queue */
1705         }
1706         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1707
1708         return len;
1709 }
1710
1711 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1712                          size_t size, int flags)
1713 {
1714         struct sock *sk = sock->sk;
1715         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1716         struct ddpehdr *ddp;
1717         int copied = 0;
1718         int err = 0;
1719         struct ddpebits ddphv;
1720         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1721                                                 flags & MSG_DONTWAIT, &err);
1722         if (!skb)
1723                 return err;
1724
1725         /* FIXME: use skb->cb to be able to use shared skbs */
1726         ddp = ddp_hdr(skb);
1727         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1728
1729         if (sk->sk_type == SOCK_RAW) {
1730                 copied = ddphv.deh_len;
1731                 if (copied > size) {
1732                         copied = size;
1733                         msg->msg_flags |= MSG_TRUNC;
1734                 }
1735
1736                 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1737         } else {
1738                 copied = ddphv.deh_len - sizeof(*ddp);
1739                 if (copied > size) {
1740                         copied = size;
1741                         msg->msg_flags |= MSG_TRUNC;
1742                 }
1743                 err = skb_copy_datagram_iovec(skb, sizeof(*ddp),
1744                                               msg->msg_iov, copied);
1745         }
1746
1747         if (!err) {
1748                 if (sat) {
1749                         sat->sat_family      = AF_APPLETALK;
1750                         sat->sat_port        = ddp->deh_sport;
1751                         sat->sat_addr.s_node = ddp->deh_snode;
1752                         sat->sat_addr.s_net  = ddp->deh_snet;
1753                 }
1754                 msg->msg_namelen = sizeof(*sat);
1755         }
1756
1757         skb_free_datagram(sk, skb);     /* Free the datagram. */
1758         return err ? : copied;
1759 }
1760
1761
1762 /*
1763  * AppleTalk ioctl calls.
1764  */
1765 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1766 {
1767         int rc = -ENOIOCTLCMD;
1768         struct sock *sk = sock->sk;
1769         void __user *argp = (void __user *)arg;
1770
1771         switch (cmd) {
1772                 /* Protocol layer */
1773                 case TIOCOUTQ: {
1774                         long amount = sk->sk_sndbuf -
1775                                       atomic_read(&sk->sk_wmem_alloc);
1776
1777                         if (amount < 0)
1778                                 amount = 0;
1779                         rc = put_user(amount, (int __user *)argp);
1780                         break;
1781                 }
1782                 case TIOCINQ: {
1783                         /*
1784                          * These two are safe on a single CPU system as only
1785                          * user tasks fiddle here
1786                          */
1787                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1788                         long amount = 0;
1789
1790                         if (skb)
1791                                 amount = skb->len - sizeof(struct ddpehdr);
1792                         rc = put_user(amount, (int __user *)argp);
1793                         break;
1794                 }
1795                 case SIOCGSTAMP:
1796                         rc = sock_get_timestamp(sk, argp);
1797                         break;
1798                 /* Routing */
1799                 case SIOCADDRT:
1800                 case SIOCDELRT:
1801                         rc = -EPERM;
1802                         if (capable(CAP_NET_ADMIN))
1803                                 rc = atrtr_ioctl(cmd, argp);
1804                         break;
1805                 /* Interface */
1806                 case SIOCGIFADDR:
1807                 case SIOCSIFADDR:
1808                 case SIOCGIFBRDADDR:
1809                 case SIOCATALKDIFADDR:
1810                 case SIOCDIFADDR:
1811                 case SIOCSARP:          /* proxy AARP */
1812                 case SIOCDARP:          /* proxy AARP */
1813                         rtnl_lock();
1814                         rc = atif_ioctl(cmd, argp);
1815                         rtnl_unlock();
1816                         break;
1817         }
1818
1819         return rc;
1820 }
1821
1822
1823 #ifdef CONFIG_COMPAT
1824 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1825 {
1826         /*
1827          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1828          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1829          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1830          * here so there is no generic SIOCPROTOPRIVATE translation in the
1831          * system.
1832          */
1833         return -ENOIOCTLCMD;
1834 }
1835 #endif
1836
1837
1838 static struct net_proto_family atalk_family_ops = {
1839         .family         = PF_APPLETALK,
1840         .create         = atalk_create,
1841         .owner          = THIS_MODULE,
1842 };
1843
1844 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1845         .family         = PF_APPLETALK,
1846         .owner          = THIS_MODULE,
1847         .release        = atalk_release,
1848         .bind           = atalk_bind,
1849         .connect        = atalk_connect,
1850         .socketpair     = sock_no_socketpair,
1851         .accept         = sock_no_accept,
1852         .getname        = atalk_getname,
1853         .poll           = datagram_poll,
1854         .ioctl          = atalk_ioctl,
1855 #ifdef CONFIG_COMPAT
1856         .compat_ioctl   = atalk_compat_ioctl,
1857 #endif
1858         .listen         = sock_no_listen,
1859         .shutdown       = sock_no_shutdown,
1860         .setsockopt     = sock_no_setsockopt,
1861         .getsockopt     = sock_no_getsockopt,
1862         .sendmsg        = atalk_sendmsg,
1863         .recvmsg        = atalk_recvmsg,
1864         .mmap           = sock_no_mmap,
1865         .sendpage       = sock_no_sendpage,
1866 };
1867
1868 #include <linux/smp_lock.h>
1869 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1870
1871 static struct notifier_block ddp_notifier = {
1872         .notifier_call  = ddp_device_event,
1873 };
1874
1875 static struct packet_type ltalk_packet_type = {
1876         .type           = __constant_htons(ETH_P_LOCALTALK),
1877         .func           = ltalk_rcv,
1878 };
1879
1880 static struct packet_type ppptalk_packet_type = {
1881         .type           = __constant_htons(ETH_P_PPPTALK),
1882         .func           = atalk_rcv,
1883 };
1884
1885 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1886
1887 /* Export symbols for use by drivers when AppleTalk is a module */
1888 EXPORT_SYMBOL(aarp_send_ddp);
1889 EXPORT_SYMBOL(atrtr_get_dev);
1890 EXPORT_SYMBOL(atalk_find_dev_addr);
1891
1892 static char atalk_err_snap[] __initdata =
1893         KERN_CRIT "Unable to register DDP with SNAP.\n";
1894
1895 /* Called by proto.c on kernel start up */
1896 static int __init atalk_init(void)
1897 {
1898         int rc = proto_register(&ddp_proto, 0);
1899
1900         if (rc != 0)
1901                 goto out;
1902
1903         (void)sock_register(&atalk_family_ops);
1904         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1905         if (!ddp_dl)
1906                 printk(atalk_err_snap);
1907
1908         dev_add_pack(&ltalk_packet_type);
1909         dev_add_pack(&ppptalk_packet_type);
1910
1911         register_netdevice_notifier(&ddp_notifier);
1912         aarp_proto_init();
1913         atalk_proc_init();
1914         atalk_register_sysctl();
1915 out:
1916         return rc;
1917 }
1918 module_init(atalk_init);
1919
1920 /*
1921  * No explicit module reference count manipulation is needed in the
1922  * protocol. Socket layer sets module reference count for us
1923  * and interfaces reference counting is done
1924  * by the network device layer.
1925  *
1926  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1927  * sockets be closed from user space.
1928  */
1929 static void __exit atalk_exit(void)
1930 {
1931 #ifdef CONFIG_SYSCTL
1932         atalk_unregister_sysctl();
1933 #endif /* CONFIG_SYSCTL */
1934         atalk_proc_exit();
1935         aarp_cleanup_module();  /* General aarp clean-up. */
1936         unregister_netdevice_notifier(&ddp_notifier);
1937         dev_remove_pack(&ltalk_packet_type);
1938         dev_remove_pack(&ppptalk_packet_type);
1939         unregister_snap_client(ddp_dl);
1940         sock_unregister(PF_APPLETALK);
1941         proto_unregister(&ddp_proto);
1942 }
1943 module_exit(atalk_exit);
1944
1945 MODULE_LICENSE("GPL");
1946 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1947 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1948 MODULE_ALIAS_NETPROTO(PF_APPLETALK);