e0d37d6dc1f81e6ec7455fe5d1f0c5acabc0ccd8
[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 #include "../core/kmap_skb.h"
65
66 struct datalink_proto *ddp_dl, *aarp_dl;
67 static const struct proto_ops atalk_dgram_ops;
68
69 /**************************************************************************\
70 *                                                                          *
71 * Handlers for the socket list.                                            *
72 *                                                                          *
73 \**************************************************************************/
74
75 HLIST_HEAD(atalk_sockets);
76 DEFINE_RWLOCK(atalk_sockets_lock);
77
78 static inline void __atalk_insert_socket(struct sock *sk)
79 {
80         sk_add_node(sk, &atalk_sockets);
81 }
82
83 static inline void atalk_remove_socket(struct sock *sk)
84 {
85         write_lock_bh(&atalk_sockets_lock);
86         sk_del_node_init(sk);
87         write_unlock_bh(&atalk_sockets_lock);
88 }
89
90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
91                                         struct atalk_iface *atif)
92 {
93         struct sock *s;
94         struct hlist_node *node;
95
96         read_lock_bh(&atalk_sockets_lock);
97         sk_for_each(s, node, &atalk_sockets) {
98                 struct atalk_sock *at = at_sk(s);
99
100                 if (to->sat_port != at->src_port)
101                         continue;
102
103                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
104                     to->sat_addr.s_node == ATADDR_BCAST)
105                         goto found;
106
107                 if (to->sat_addr.s_net == at->src_net &&
108                     (to->sat_addr.s_node == at->src_node ||
109                      to->sat_addr.s_node == ATADDR_BCAST ||
110                      to->sat_addr.s_node == ATADDR_ANYNODE))
111                         goto found;
112
113                 /* XXXX.0 -- we got a request for this router. make sure
114                  * that the node is appropriately set. */
115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
116                     to->sat_addr.s_net != ATADDR_ANYNET &&
117                     atif->address.s_node == at->src_node) {
118                         to->sat_addr.s_node = atif->address.s_node;
119                         goto found;
120                 }
121         }
122         s = NULL;
123 found:
124         read_unlock_bh(&atalk_sockets_lock);
125         return s;
126 }
127
128 /**
129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
130  * @sk - socket to insert in the list if it is not there already
131  * @sat - address to search for
132  *
133  * Try to find a socket matching ADDR in the socket list, if found then return
134  * it. If not, insert SK into the socket list.
135  *
136  * This entire operation must execute atomically.
137  */
138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
139                                                 struct sockaddr_at *sat)
140 {
141         struct sock *s;
142         struct hlist_node *node;
143         struct atalk_sock *at;
144
145         write_lock_bh(&atalk_sockets_lock);
146         sk_for_each(s, node, &atalk_sockets) {
147                 at = at_sk(s);
148
149                 if (at->src_net == sat->sat_addr.s_net &&
150                     at->src_node == sat->sat_addr.s_node &&
151                     at->src_port == sat->sat_port)
152                         goto found;
153         }
154         s = NULL;
155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
156 found:
157         write_unlock_bh(&atalk_sockets_lock);
158         return s;
159 }
160
161 static void atalk_destroy_timer(unsigned long data)
162 {
163         struct sock *sk = (struct sock *)data;
164
165         if (atomic_read(&sk->sk_wmem_alloc) ||
166             atomic_read(&sk->sk_rmem_alloc)) {
167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
168                 add_timer(&sk->sk_timer);
169         } else
170                 sock_put(sk);
171 }
172
173 static inline void atalk_destroy_socket(struct sock *sk)
174 {
175         atalk_remove_socket(sk);
176         skb_queue_purge(&sk->sk_receive_queue);
177
178         if (atomic_read(&sk->sk_wmem_alloc) ||
179             atomic_read(&sk->sk_rmem_alloc)) {
180                 init_timer(&sk->sk_timer);
181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
182                 sk->sk_timer.function   = atalk_destroy_timer;
183                 sk->sk_timer.data       = (unsigned long)sk;
184                 add_timer(&sk->sk_timer);
185         } else
186                 sock_put(sk);
187 }
188
189 /**************************************************************************\
190 *                                                                          *
191 * Routing tables for the AppleTalk socket layer.                           *
192 *                                                                          *
193 \**************************************************************************/
194
195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
196 struct atalk_route *atalk_routes;
197 DEFINE_RWLOCK(atalk_routes_lock);
198
199 struct atalk_iface *atalk_interfaces;
200 DEFINE_RWLOCK(atalk_interfaces_lock);
201
202 /* For probing devices or in a routerless network */
203 struct atalk_route atrtr_default;
204
205 /* AppleTalk interface control */
206 /*
207  * Drop a device. Doesn't drop any of its routes - that is the caller's
208  * problem. Called when we down the interface or delete the address.
209  */
210 static void atif_drop_device(struct net_device *dev)
211 {
212         struct atalk_iface **iface = &atalk_interfaces;
213         struct atalk_iface *tmp;
214
215         write_lock_bh(&atalk_interfaces_lock);
216         while ((tmp = *iface) != NULL) {
217                 if (tmp->dev == dev) {
218                         *iface = tmp->next;
219                         dev_put(dev);
220                         kfree(tmp);
221                         dev->atalk_ptr = NULL;
222                 } else
223                         iface = &tmp->next;
224         }
225         write_unlock_bh(&atalk_interfaces_lock);
226 }
227
228 static struct atalk_iface *atif_add_device(struct net_device *dev,
229                                            struct atalk_addr *sa)
230 {
231         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
232
233         if (!iface)
234                 goto out;
235
236         dev_hold(dev);
237         iface->dev = dev;
238         dev->atalk_ptr = iface;
239         iface->address = *sa;
240         iface->status = 0;
241
242         write_lock_bh(&atalk_interfaces_lock);
243         iface->next = atalk_interfaces;
244         atalk_interfaces = iface;
245         write_unlock_bh(&atalk_interfaces_lock);
246 out:
247         return iface;
248 }
249
250 /* Perform phase 2 AARP probing on our tentative address */
251 static int atif_probe_device(struct atalk_iface *atif)
252 {
253         int netrange = ntohs(atif->nets.nr_lastnet) -
254                         ntohs(atif->nets.nr_firstnet) + 1;
255         int probe_net = ntohs(atif->address.s_net);
256         int probe_node = atif->address.s_node;
257         int netct, nodect;
258
259         /* Offset the network we start probing with */
260         if (probe_net == ATADDR_ANYNET) {
261                 probe_net = ntohs(atif->nets.nr_firstnet);
262                 if (netrange)
263                         probe_net += jiffies % netrange;
264         }
265         if (probe_node == ATADDR_ANYNODE)
266                 probe_node = jiffies & 0xFF;
267
268         /* Scan the networks */
269         atif->status |= ATIF_PROBE;
270         for (netct = 0; netct <= netrange; netct++) {
271                 /* Sweep the available nodes from a given start */
272                 atif->address.s_net = htons(probe_net);
273                 for (nodect = 0; nodect < 256; nodect++) {
274                         atif->address.s_node = (nodect + probe_node) & 0xFF;
275                         if (atif->address.s_node > 0 &&
276                             atif->address.s_node < 254) {
277                                 /* Probe a proposed address */
278                                 aarp_probe_network(atif);
279
280                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
281                                         atif->status &= ~ATIF_PROBE;
282                                         return 0;
283                                 }
284                         }
285                         atif->status &= ~ATIF_PROBE_FAIL;
286                 }
287                 probe_net++;
288                 if (probe_net > ntohs(atif->nets.nr_lastnet))
289                         probe_net = ntohs(atif->nets.nr_firstnet);
290         }
291         atif->status &= ~ATIF_PROBE;
292
293         return -EADDRINUSE;     /* Network is full... */
294 }
295
296
297 /* Perform AARP probing for a proxy address */
298 static int atif_proxy_probe_device(struct atalk_iface *atif,
299                                    struct atalk_addr* proxy_addr)
300 {
301         int netrange = ntohs(atif->nets.nr_lastnet) -
302                         ntohs(atif->nets.nr_firstnet) + 1;
303         /* we probe the interface's network */
304         int probe_net = ntohs(atif->address.s_net);
305         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
306         int netct, nodect;
307
308         /* Offset the network we start probing with */
309         if (probe_net == ATADDR_ANYNET) {
310                 probe_net = ntohs(atif->nets.nr_firstnet);
311                 if (netrange)
312                         probe_net += jiffies % netrange;
313         }
314
315         if (probe_node == ATADDR_ANYNODE)
316                 probe_node = jiffies & 0xFF;
317
318         /* Scan the networks */
319         for (netct = 0; netct <= netrange; netct++) {
320                 /* Sweep the available nodes from a given start */
321                 proxy_addr->s_net = htons(probe_net);
322                 for (nodect = 0; nodect < 256; nodect++) {
323                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
324                         if (proxy_addr->s_node > 0 &&
325                             proxy_addr->s_node < 254) {
326                                 /* Tell AARP to probe a proposed address */
327                                 int ret = aarp_proxy_probe_network(atif,
328                                                                     proxy_addr);
329
330                                 if (ret != -EADDRINUSE)
331                                         return ret;
332                         }
333                 }
334                 probe_net++;
335                 if (probe_net > ntohs(atif->nets.nr_lastnet))
336                         probe_net = ntohs(atif->nets.nr_firstnet);
337         }
338
339         return -EADDRINUSE;     /* Network is full... */
340 }
341
342
343 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
344 {
345         struct atalk_iface *iface = dev->atalk_ptr;
346         return iface ? &iface->address : NULL;
347 }
348
349 static struct atalk_addr *atalk_find_primary(void)
350 {
351         struct atalk_iface *fiface = NULL;
352         struct atalk_addr *retval;
353         struct atalk_iface *iface;
354
355         /*
356          * Return a point-to-point interface only if
357          * there is no non-ptp interface available.
358          */
359         read_lock_bh(&atalk_interfaces_lock);
360         for (iface = atalk_interfaces; iface; iface = iface->next) {
361                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
362                         fiface = iface;
363                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
364                         retval = &iface->address;
365                         goto out;
366                 }
367         }
368
369         if (fiface)
370                 retval = &fiface->address;
371         else if (atalk_interfaces)
372                 retval = &atalk_interfaces->address;
373         else
374                 retval = NULL;
375 out:
376         read_unlock_bh(&atalk_interfaces_lock);
377         return retval;
378 }
379
380 /*
381  * Find a match for 'any network' - ie any of our interfaces with that
382  * node number will do just nicely.
383  */
384 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
385 {
386         struct atalk_iface *iface = dev->atalk_ptr;
387
388         if (!iface || iface->status & ATIF_PROBE)
389                 goto out_err;
390
391         if (node != ATADDR_BCAST &&
392             iface->address.s_node != node &&
393             node != ATADDR_ANYNODE)
394                 goto out_err;
395 out:
396         return iface;
397 out_err:
398         iface = NULL;
399         goto out;
400 }
401
402 /* Find a match for a specific network:node pair */
403 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
404 {
405         struct atalk_iface *iface;
406
407         read_lock_bh(&atalk_interfaces_lock);
408         for (iface = atalk_interfaces; iface; iface = iface->next) {
409                 if ((node == ATADDR_BCAST ||
410                      node == ATADDR_ANYNODE ||
411                      iface->address.s_node == node) &&
412                     iface->address.s_net == net &&
413                     !(iface->status & ATIF_PROBE))
414                         break;
415
416                 /* XXXX.0 -- net.0 returns the iface associated with net */
417                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
418                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
419                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
420                         break;
421         }
422         read_unlock_bh(&atalk_interfaces_lock);
423         return iface;
424 }
425
426
427 /*
428  * Find a route for an AppleTalk packet. This ought to get cached in
429  * the socket (later on...). We know about host routes and the fact
430  * that a route must be direct to broadcast.
431  */
432 static struct atalk_route *atrtr_find(struct atalk_addr *target)
433 {
434         /*
435          * we must search through all routes unless we find a
436          * host route, because some host routes might overlap
437          * network routes
438          */
439         struct atalk_route *net_route = NULL;
440         struct atalk_route *r;
441
442         read_lock_bh(&atalk_routes_lock);
443         for (r = atalk_routes; r; r = r->next) {
444                 if (!(r->flags & RTF_UP))
445                         continue;
446
447                 if (r->target.s_net == target->s_net) {
448                         if (r->flags & RTF_HOST) {
449                                 /*
450                                  * if this host route is for the target,
451                                  * the we're done
452                                  */
453                                 if (r->target.s_node == target->s_node)
454                                         goto out;
455                         } else
456                                 /*
457                                  * this route will work if there isn't a
458                                  * direct host route, so cache it
459                                  */
460                                 net_route = r;
461                 }
462         }
463
464         /*
465          * if we found a network route but not a direct host
466          * route, then return it
467          */
468         if (net_route)
469                 r = net_route;
470         else if (atrtr_default.dev)
471                 r = &atrtr_default;
472         else /* No route can be found */
473                 r = NULL;
474 out:
475         read_unlock_bh(&atalk_routes_lock);
476         return r;
477 }
478
479
480 /*
481  * Given an AppleTalk network, find the device to use. This can be
482  * a simple lookup.
483  */
484 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
485 {
486         struct atalk_route *atr = atrtr_find(sa);
487         return atr ? atr->dev : NULL;
488 }
489
490 /* Set up a default router */
491 static void atrtr_set_default(struct net_device *dev)
492 {
493         atrtr_default.dev            = dev;
494         atrtr_default.flags          = RTF_UP;
495         atrtr_default.gateway.s_net  = htons(0);
496         atrtr_default.gateway.s_node = 0;
497 }
498
499 /*
500  * Add a router. Basically make sure it looks valid and stuff the
501  * entry in the list. While it uses netranges we always set them to one
502  * entry to work like netatalk.
503  */
504 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
505 {
506         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
507         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
508         struct atalk_route *rt;
509         struct atalk_iface *iface, *riface;
510         int retval = -EINVAL;
511
512         /*
513          * Fixme: Raise/Lower a routing change semaphore for these
514          * operations.
515          */
516
517         /* Validate the request */
518         if (ta->sat_family != AF_APPLETALK ||
519             (!devhint && ga->sat_family != AF_APPLETALK))
520                 goto out;
521
522         /* Now walk the routing table and make our decisions */
523         write_lock_bh(&atalk_routes_lock);
524         for (rt = atalk_routes; rt; rt = rt->next) {
525                 if (r->rt_flags != rt->flags)
526                         continue;
527
528                 if (ta->sat_addr.s_net == rt->target.s_net) {
529                         if (!(rt->flags & RTF_HOST))
530                                 break;
531                         if (ta->sat_addr.s_node == rt->target.s_node)
532                                 break;
533                 }
534         }
535
536         if (!devhint) {
537                 riface = NULL;
538
539                 read_lock_bh(&atalk_interfaces_lock);
540                 for (iface = atalk_interfaces; iface; iface = iface->next) {
541                         if (!riface &&
542                             ntohs(ga->sat_addr.s_net) >=
543                                         ntohs(iface->nets.nr_firstnet) &&
544                             ntohs(ga->sat_addr.s_net) <=
545                                         ntohs(iface->nets.nr_lastnet))
546                                 riface = iface;
547
548                         if (ga->sat_addr.s_net == iface->address.s_net &&
549                             ga->sat_addr.s_node == iface->address.s_node)
550                                 riface = iface;
551                 }
552                 read_unlock_bh(&atalk_interfaces_lock);
553
554                 retval = -ENETUNREACH;
555                 if (!riface)
556                         goto out_unlock;
557
558                 devhint = riface->dev;
559         }
560
561         if (!rt) {
562                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
563
564                 retval = -ENOBUFS;
565                 if (!rt)
566                         goto out_unlock;
567
568                 rt->next = atalk_routes;
569                 atalk_routes = rt;
570         }
571
572         /* Fill in the routing entry */
573         rt->target  = ta->sat_addr;
574         dev_hold(devhint);
575         rt->dev     = devhint;
576         rt->flags   = r->rt_flags;
577         rt->gateway = ga->sat_addr;
578
579         retval = 0;
580 out_unlock:
581         write_unlock_bh(&atalk_routes_lock);
582 out:
583         return retval;
584 }
585
586 /* Delete a route. Find it and discard it */
587 static int atrtr_delete(struct atalk_addr * addr)
588 {
589         struct atalk_route **r = &atalk_routes;
590         int retval = 0;
591         struct atalk_route *tmp;
592
593         write_lock_bh(&atalk_routes_lock);
594         while ((tmp = *r) != NULL) {
595                 if (tmp->target.s_net == addr->s_net &&
596                     (!(tmp->flags&RTF_GATEWAY) ||
597                      tmp->target.s_node == addr->s_node)) {
598                         *r = tmp->next;
599                         dev_put(tmp->dev);
600                         kfree(tmp);
601                         goto out;
602                 }
603                 r = &tmp->next;
604         }
605         retval = -ENOENT;
606 out:
607         write_unlock_bh(&atalk_routes_lock);
608         return retval;
609 }
610
611 /*
612  * Called when a device is downed. Just throw away any routes
613  * via it.
614  */
615 static void atrtr_device_down(struct net_device *dev)
616 {
617         struct atalk_route **r = &atalk_routes;
618         struct atalk_route *tmp;
619
620         write_lock_bh(&atalk_routes_lock);
621         while ((tmp = *r) != NULL) {
622                 if (tmp->dev == dev) {
623                         *r = tmp->next;
624                         dev_put(dev);
625                         kfree(tmp);
626                 } else
627                         r = &tmp->next;
628         }
629         write_unlock_bh(&atalk_routes_lock);
630
631         if (atrtr_default.dev == dev)
632                 atrtr_set_default(NULL);
633 }
634
635 /* Actually down the interface */
636 static inline void atalk_dev_down(struct net_device *dev)
637 {
638         atrtr_device_down(dev); /* Remove all routes for the device */
639         aarp_device_down(dev);  /* Remove AARP entries for the device */
640         atif_drop_device(dev);  /* Remove the device */
641 }
642
643 /*
644  * A device event has occurred. Watch for devices going down and
645  * delete our use of them (iface and route).
646  */
647 static int ddp_device_event(struct notifier_block *this, unsigned long event,
648                             void *ptr)
649 {
650         struct net_device *dev = ptr;
651
652         if (dev->nd_net != &init_net)
653                 return NOTIFY_DONE;
654
655         if (event == NETDEV_DOWN)
656                 /* Discard any use of this */
657                 atalk_dev_down(dev);
658
659         return NOTIFY_DONE;
660 }
661
662 /* ioctl calls. Shouldn't even need touching */
663 /* Device configuration ioctl calls */
664 static int atif_ioctl(int cmd, void __user *arg)
665 {
666         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
667         struct ifreq atreq;
668         struct atalk_netrange *nr;
669         struct sockaddr_at *sa;
670         struct net_device *dev;
671         struct atalk_iface *atif;
672         int ct;
673         int limit;
674         struct rtentry rtdef;
675         int add_route;
676
677         if (copy_from_user(&atreq, arg, sizeof(atreq)))
678                 return -EFAULT;
679
680         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
681         if (!dev)
682                 return -ENODEV;
683
684         sa = (struct sockaddr_at *)&atreq.ifr_addr;
685         atif = atalk_find_dev(dev);
686
687         switch (cmd) {
688                 case SIOCSIFADDR:
689                         if (!capable(CAP_NET_ADMIN))
690                                 return -EPERM;
691                         if (sa->sat_family != AF_APPLETALK)
692                                 return -EINVAL;
693                         if (dev->type != ARPHRD_ETHER &&
694                             dev->type != ARPHRD_LOOPBACK &&
695                             dev->type != ARPHRD_LOCALTLK &&
696                             dev->type != ARPHRD_PPP)
697                                 return -EPROTONOSUPPORT;
698
699                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
700                         add_route = 1;
701
702                         /*
703                          * if this is a point-to-point iface, and we already
704                          * have an iface for this AppleTalk address, then we
705                          * should not add a route
706                          */
707                         if ((dev->flags & IFF_POINTOPOINT) &&
708                             atalk_find_interface(sa->sat_addr.s_net,
709                                                  sa->sat_addr.s_node)) {
710                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
711                                                   "interface added with "
712                                                   "existing address\n");
713                                 add_route = 0;
714                         }
715
716                         /*
717                          * Phase 1 is fine on LocalTalk but we don't do
718                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
719                          */
720                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
721                                 return -EPROTONOSUPPORT;
722                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
723                             sa->sat_addr.s_node == 254)
724                                 return -EINVAL;
725                         if (atif) {
726                                 /* Already setting address */
727                                 if (atif->status & ATIF_PROBE)
728                                         return -EBUSY;
729
730                                 atif->address.s_net  = sa->sat_addr.s_net;
731                                 atif->address.s_node = sa->sat_addr.s_node;
732                                 atrtr_device_down(dev); /* Flush old routes */
733                         } else {
734                                 atif = atif_add_device(dev, &sa->sat_addr);
735                                 if (!atif)
736                                         return -ENOMEM;
737                         }
738                         atif->nets = *nr;
739
740                         /*
741                          * Check if the chosen address is used. If so we
742                          * error and atalkd will try another.
743                          */
744
745                         if (!(dev->flags & IFF_LOOPBACK) &&
746                             !(dev->flags & IFF_POINTOPOINT) &&
747                             atif_probe_device(atif) < 0) {
748                                 atif_drop_device(dev);
749                                 return -EADDRINUSE;
750                         }
751
752                         /* Hey it worked - add the direct routes */
753                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
754                         sa->sat_family = AF_APPLETALK;
755                         sa->sat_addr.s_net  = atif->address.s_net;
756                         sa->sat_addr.s_node = atif->address.s_node;
757                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
758                         rtdef.rt_flags = RTF_UP;
759                         sa->sat_family = AF_APPLETALK;
760                         sa->sat_addr.s_node = ATADDR_ANYNODE;
761                         if (dev->flags & IFF_LOOPBACK ||
762                             dev->flags & IFF_POINTOPOINT)
763                                 rtdef.rt_flags |= RTF_HOST;
764
765                         /* Routerless initial state */
766                         if (nr->nr_firstnet == htons(0) &&
767                             nr->nr_lastnet == htons(0xFFFE)) {
768                                 sa->sat_addr.s_net = atif->address.s_net;
769                                 atrtr_create(&rtdef, dev);
770                                 atrtr_set_default(dev);
771                         } else {
772                                 limit = ntohs(nr->nr_lastnet);
773                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
774                                         printk(KERN_WARNING "Too many routes/"
775                                                             "iface.\n");
776                                         return -EINVAL;
777                                 }
778                                 if (add_route)
779                                         for (ct = ntohs(nr->nr_firstnet);
780                                              ct <= limit; ct++) {
781                                                 sa->sat_addr.s_net = htons(ct);
782                                                 atrtr_create(&rtdef, dev);
783                                         }
784                         }
785                         dev_mc_add(dev, aarp_mcast, 6, 1);
786                         return 0;
787
788                 case SIOCGIFADDR:
789                         if (!atif)
790                                 return -EADDRNOTAVAIL;
791
792                         sa->sat_family = AF_APPLETALK;
793                         sa->sat_addr = atif->address;
794                         break;
795
796                 case SIOCGIFBRDADDR:
797                         if (!atif)
798                                 return -EADDRNOTAVAIL;
799
800                         sa->sat_family = AF_APPLETALK;
801                         sa->sat_addr.s_net = atif->address.s_net;
802                         sa->sat_addr.s_node = ATADDR_BCAST;
803                         break;
804
805                 case SIOCATALKDIFADDR:
806                 case SIOCDIFADDR:
807                         if (!capable(CAP_NET_ADMIN))
808                                 return -EPERM;
809                         if (sa->sat_family != AF_APPLETALK)
810                                 return -EINVAL;
811                         atalk_dev_down(dev);
812                         break;
813
814                 case SIOCSARP:
815                         if (!capable(CAP_NET_ADMIN))
816                                 return -EPERM;
817                         if (sa->sat_family != AF_APPLETALK)
818                                 return -EINVAL;
819                         if (!atif)
820                                 return -EADDRNOTAVAIL;
821
822                         /*
823                          * for now, we only support proxy AARP on ELAP;
824                          * we should be able to do it for LocalTalk, too.
825                          */
826                         if (dev->type != ARPHRD_ETHER)
827                                 return -EPROTONOSUPPORT;
828
829                         /*
830                          * atif points to the current interface on this network;
831                          * we aren't concerned about its current status (at
832                          * least for now), but it has all the settings about
833                          * the network we're going to probe. Consequently, it
834                          * must exist.
835                          */
836                         if (!atif)
837                                 return -EADDRNOTAVAIL;
838
839                         nr = (struct atalk_netrange *)&(atif->nets);
840                         /*
841                          * Phase 1 is fine on Localtalk but we don't do
842                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
843                          */
844                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
845                                 return -EPROTONOSUPPORT;
846
847                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
848                             sa->sat_addr.s_node == 254)
849                                 return -EINVAL;
850
851                         /*
852                          * Check if the chosen address is used. If so we
853                          * error and ATCP will try another.
854                          */
855                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
856                                 return -EADDRINUSE;
857
858                         /*
859                          * We now have an address on the local network, and
860                          * the AARP code will defend it for us until we take it
861                          * down. We don't set up any routes right now, because
862                          * ATCP will install them manually via SIOCADDRT.
863                          */
864                         break;
865
866                 case SIOCDARP:
867                         if (!capable(CAP_NET_ADMIN))
868                                 return -EPERM;
869                         if (sa->sat_family != AF_APPLETALK)
870                                 return -EINVAL;
871                         if (!atif)
872                                 return -EADDRNOTAVAIL;
873
874                         /* give to aarp module to remove proxy entry */
875                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
876                         return 0;
877         }
878
879         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
880 }
881
882 /* Routing ioctl() calls */
883 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
884 {
885         struct rtentry rt;
886
887         if (copy_from_user(&rt, arg, sizeof(rt)))
888                 return -EFAULT;
889
890         switch (cmd) {
891                 case SIOCDELRT:
892                         if (rt.rt_dst.sa_family != AF_APPLETALK)
893                                 return -EINVAL;
894                         return atrtr_delete(&((struct sockaddr_at *)
895                                                 &rt.rt_dst)->sat_addr);
896
897                 case SIOCADDRT: {
898                         struct net_device *dev = NULL;
899                         if (rt.rt_dev) {
900                                 char name[IFNAMSIZ];
901                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
902                                         return -EFAULT;
903                                 name[IFNAMSIZ-1] = '\0';
904                                 dev = __dev_get_by_name(&init_net, name);
905                                 if (!dev)
906                                         return -ENODEV;
907                         }
908                         return atrtr_create(&rt, dev);
909                 }
910         }
911         return -EINVAL;
912 }
913
914 /**************************************************************************\
915 *                                                                          *
916 * Handling for system calls applied via the various interfaces to an       *
917 * AppleTalk socket object.                                                 *
918 *                                                                          *
919 \**************************************************************************/
920
921 /*
922  * Checksum: This is 'optional'. It's quite likely also a good
923  * candidate for assembler hackery 8)
924  */
925 static unsigned long atalk_sum_partial(const unsigned char *data,
926                                        int len, unsigned long sum)
927 {
928         /* This ought to be unwrapped neatly. I'll trust gcc for now */
929         while (len--) {
930                 sum += *data;
931                 sum <<= 1;
932                 if (sum & 0x10000) {
933                         sum++;
934                         sum &= 0xffff;
935                 }
936                 data++;
937         }
938         return sum;
939 }
940
941 /*  Checksum skb data --  similar to skb_checksum  */
942 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
943                                    int len, unsigned long sum)
944 {
945         int start = skb_headlen(skb);
946         int i, copy;
947
948         /* checksum stuff in header space */
949         if ( (copy = start - offset) > 0) {
950                 if (copy > len)
951                         copy = len;
952                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
953                 if ( (len -= copy) == 0)
954                         return sum;
955
956                 offset += copy;
957         }
958
959         /* checksum stuff in frags */
960         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
961                 int end;
962
963                 BUG_TRAP(start <= offset + len);
964
965                 end = start + skb_shinfo(skb)->frags[i].size;
966                 if ((copy = end - offset) > 0) {
967                         u8 *vaddr;
968                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
969
970                         if (copy > len)
971                                 copy = len;
972                         vaddr = kmap_skb_frag(frag);
973                         sum = atalk_sum_partial(vaddr + frag->page_offset +
974                                                   offset - start, copy, sum);
975                         kunmap_skb_frag(vaddr);
976
977                         if (!(len -= copy))
978                                 return sum;
979                         offset += copy;
980                 }
981                 start = end;
982         }
983
984         if (skb_shinfo(skb)->frag_list) {
985                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
986
987                 for (; list; list = list->next) {
988                         int end;
989
990                         BUG_TRAP(start <= offset + len);
991
992                         end = start + list->len;
993                         if ((copy = end - offset) > 0) {
994                                 if (copy > len)
995                                         copy = len;
996                                 sum = atalk_sum_skb(list, offset - start,
997                                                     copy, sum);
998                                 if ((len -= copy) == 0)
999                                         return sum;
1000                                 offset += copy;
1001                         }
1002                         start = end;
1003                 }
1004         }
1005
1006         BUG_ON(len > 0);
1007
1008         return sum;
1009 }
1010
1011 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1012 {
1013         unsigned long sum;
1014
1015         /* skip header 4 bytes */
1016         sum = atalk_sum_skb(skb, 4, len-4, 0);
1017
1018         /* Use 0xFFFF for 0. 0 itself means none */
1019         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1020 }
1021
1022 static struct proto ddp_proto = {
1023         .name     = "DDP",
1024         .owner    = THIS_MODULE,
1025         .obj_size = sizeof(struct atalk_sock),
1026 };
1027
1028 /*
1029  * Create a socket. Initialise the socket, blank the addresses
1030  * set the state.
1031  */
1032 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1033 {
1034         struct sock *sk;
1035         int rc = -ESOCKTNOSUPPORT;
1036
1037         if (net != &init_net)
1038                 return -EAFNOSUPPORT;
1039
1040         /*
1041          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1042          * and gives you the full ELAP frame. Should be handy for CAP 8)
1043          */
1044         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1045                 goto out;
1046         rc = -ENOMEM;
1047         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1048         if (!sk)
1049                 goto out;
1050         rc = 0;
1051         sock->ops = &atalk_dgram_ops;
1052         sock_init_data(sock, sk);
1053
1054         /* Checksums on by default */
1055         sock_set_flag(sk, SOCK_ZAPPED);
1056 out:
1057         return rc;
1058 }
1059
1060 /* Free a socket. No work needed */
1061 static int atalk_release(struct socket *sock)
1062 {
1063         struct sock *sk = sock->sk;
1064
1065         if (sk) {
1066                 sock_orphan(sk);
1067                 sock->sk = NULL;
1068                 atalk_destroy_socket(sk);
1069         }
1070         return 0;
1071 }
1072
1073 /**
1074  * atalk_pick_and_bind_port - Pick a source port when one is not given
1075  * @sk - socket to insert into the tables
1076  * @sat - address to search for
1077  *
1078  * Pick a source port when one is not given. If we can find a suitable free
1079  * one, we insert the socket into the tables using it.
1080  *
1081  * This whole operation must be atomic.
1082  */
1083 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1084 {
1085         int retval;
1086
1087         write_lock_bh(&atalk_sockets_lock);
1088
1089         for (sat->sat_port = ATPORT_RESERVED;
1090              sat->sat_port < ATPORT_LAST;
1091              sat->sat_port++) {
1092                 struct sock *s;
1093                 struct hlist_node *node;
1094
1095                 sk_for_each(s, node, &atalk_sockets) {
1096                         struct atalk_sock *at = at_sk(s);
1097
1098                         if (at->src_net == sat->sat_addr.s_net &&
1099                             at->src_node == sat->sat_addr.s_node &&
1100                             at->src_port == sat->sat_port)
1101                                 goto try_next_port;
1102                 }
1103
1104                 /* Wheee, it's free, assign and insert. */
1105                 __atalk_insert_socket(sk);
1106                 at_sk(sk)->src_port = sat->sat_port;
1107                 retval = 0;
1108                 goto out;
1109
1110 try_next_port:;
1111         }
1112
1113         retval = -EBUSY;
1114 out:
1115         write_unlock_bh(&atalk_sockets_lock);
1116         return retval;
1117 }
1118
1119 static int atalk_autobind(struct sock *sk)
1120 {
1121         struct atalk_sock *at = at_sk(sk);
1122         struct sockaddr_at sat;
1123         struct atalk_addr *ap = atalk_find_primary();
1124         int n = -EADDRNOTAVAIL;
1125
1126         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1127                 goto out;
1128
1129         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1130         at->src_node = sat.sat_addr.s_node = ap->s_node;
1131
1132         n = atalk_pick_and_bind_port(sk, &sat);
1133         if (!n)
1134                 sock_reset_flag(sk, SOCK_ZAPPED);
1135 out:
1136         return n;
1137 }
1138
1139 /* Set the address 'our end' of the connection */
1140 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1141 {
1142         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1143         struct sock *sk = sock->sk;
1144         struct atalk_sock *at = at_sk(sk);
1145
1146         if (!sock_flag(sk, SOCK_ZAPPED) ||
1147             addr_len != sizeof(struct sockaddr_at))
1148                 return -EINVAL;
1149
1150         if (addr->sat_family != AF_APPLETALK)
1151                 return -EAFNOSUPPORT;
1152
1153         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1154                 struct atalk_addr *ap = atalk_find_primary();
1155
1156                 if (!ap)
1157                         return -EADDRNOTAVAIL;
1158
1159                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1160                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1161         } else {
1162                 if (!atalk_find_interface(addr->sat_addr.s_net,
1163                                           addr->sat_addr.s_node))
1164                         return -EADDRNOTAVAIL;
1165
1166                 at->src_net  = addr->sat_addr.s_net;
1167                 at->src_node = addr->sat_addr.s_node;
1168         }
1169
1170         if (addr->sat_port == ATADDR_ANYPORT) {
1171                 int n = atalk_pick_and_bind_port(sk, addr);
1172
1173                 if (n < 0)
1174                         return n;
1175         } else {
1176                 at->src_port = addr->sat_port;
1177
1178                 if (atalk_find_or_insert_socket(sk, addr))
1179                         return -EADDRINUSE;
1180         }
1181
1182         sock_reset_flag(sk, SOCK_ZAPPED);
1183         return 0;
1184 }
1185
1186 /* Set the address we talk to */
1187 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1188                          int addr_len, int flags)
1189 {
1190         struct sock *sk = sock->sk;
1191         struct atalk_sock *at = at_sk(sk);
1192         struct sockaddr_at *addr;
1193
1194         sk->sk_state   = TCP_CLOSE;
1195         sock->state = SS_UNCONNECTED;
1196
1197         if (addr_len != sizeof(*addr))
1198                 return -EINVAL;
1199
1200         addr = (struct sockaddr_at *)uaddr;
1201
1202         if (addr->sat_family != AF_APPLETALK)
1203                 return -EAFNOSUPPORT;
1204
1205         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1206             !sock_flag(sk, SOCK_BROADCAST)) {
1207 #if 1
1208                 printk(KERN_WARNING "%s is broken and did not set "
1209                                     "SO_BROADCAST. It will break when 2.2 is "
1210                                     "released.\n",
1211                         current->comm);
1212 #else
1213                 return -EACCES;
1214 #endif
1215         }
1216
1217         if (sock_flag(sk, SOCK_ZAPPED))
1218                 if (atalk_autobind(sk) < 0)
1219                         return -EBUSY;
1220
1221         if (!atrtr_get_dev(&addr->sat_addr))
1222                 return -ENETUNREACH;
1223
1224         at->dest_port = addr->sat_port;
1225         at->dest_net  = addr->sat_addr.s_net;
1226         at->dest_node = addr->sat_addr.s_node;
1227
1228         sock->state  = SS_CONNECTED;
1229         sk->sk_state = TCP_ESTABLISHED;
1230         return 0;
1231 }
1232
1233 /*
1234  * Find the name of an AppleTalk socket. Just copy the right
1235  * fields into the sockaddr.
1236  */
1237 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1238                          int *uaddr_len, int peer)
1239 {
1240         struct sockaddr_at sat;
1241         struct sock *sk = sock->sk;
1242         struct atalk_sock *at = at_sk(sk);
1243
1244         if (sock_flag(sk, SOCK_ZAPPED))
1245                 if (atalk_autobind(sk) < 0)
1246                         return -ENOBUFS;
1247
1248         *uaddr_len = sizeof(struct sockaddr_at);
1249
1250         if (peer) {
1251                 if (sk->sk_state != TCP_ESTABLISHED)
1252                         return -ENOTCONN;
1253
1254                 sat.sat_addr.s_net  = at->dest_net;
1255                 sat.sat_addr.s_node = at->dest_node;
1256                 sat.sat_port        = at->dest_port;
1257         } else {
1258                 sat.sat_addr.s_net  = at->src_net;
1259                 sat.sat_addr.s_node = at->src_node;
1260                 sat.sat_port        = at->src_port;
1261         }
1262
1263         sat.sat_family = AF_APPLETALK;
1264         memcpy(uaddr, &sat, sizeof(sat));
1265         return 0;
1266 }
1267
1268 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1269 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1270 {
1271         return skb->data[12] == 22;
1272 }
1273
1274 static int handle_ip_over_ddp(struct sk_buff *skb)
1275 {
1276         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1277         struct net_device_stats *stats;
1278
1279         /* This needs to be able to handle ipddp"N" devices */
1280         if (!dev)
1281                 return -ENODEV;
1282
1283         skb->protocol = htons(ETH_P_IP);
1284         skb_pull(skb, 13);
1285         skb->dev   = dev;
1286         skb_reset_transport_header(skb);
1287
1288         stats = dev->priv;
1289         stats->rx_packets++;
1290         stats->rx_bytes += skb->len + 13;
1291         netif_rx(skb);  /* Send the SKB up to a higher place. */
1292         return 0;
1293 }
1294 #else
1295 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1296 #define is_ip_over_ddp(skb) 0
1297 #define handle_ip_over_ddp(skb) 0
1298 #endif
1299
1300 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1301                                struct ddpehdr *ddp, __u16 len_hops,
1302                                int origlen)
1303 {
1304         struct atalk_route *rt;
1305         struct atalk_addr ta;
1306
1307         /*
1308          * Don't route multicast, etc., packets, or packets sent to "this
1309          * network"
1310          */
1311         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1312                 /*
1313                  * FIXME:
1314                  *
1315                  * Can it ever happen that a packet is from a PPP iface and
1316                  * needs to be broadcast onto the default network?
1317                  */
1318                 if (dev->type == ARPHRD_PPP)
1319                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1320                                           "packet received from PPP iface\n");
1321                 goto free_it;
1322         }
1323
1324         ta.s_net  = ddp->deh_dnet;
1325         ta.s_node = ddp->deh_dnode;
1326
1327         /* Route the packet */
1328         rt = atrtr_find(&ta);
1329         /* increment hops count */
1330         len_hops += 1 << 10;
1331         if (!rt || !(len_hops & (15 << 10)))
1332                 goto free_it;
1333
1334         /* FIXME: use skb->cb to be able to use shared skbs */
1335
1336         /*
1337          * Route goes through another gateway, so set the target to the
1338          * gateway instead.
1339          */
1340
1341         if (rt->flags & RTF_GATEWAY) {
1342                 ta.s_net  = rt->gateway.s_net;
1343                 ta.s_node = rt->gateway.s_node;
1344         }
1345
1346         /* Fix up skb->len field */
1347         skb_trim(skb, min_t(unsigned int, origlen,
1348                             (rt->dev->hard_header_len +
1349                              ddp_dl->header_length + (len_hops & 1023))));
1350
1351         /* FIXME: use skb->cb to be able to use shared skbs */
1352         ddp->deh_len_hops = htons(len_hops);
1353
1354         /*
1355          * Send the buffer onwards
1356          *
1357          * Now we must always be careful. If it's come from LocalTalk to
1358          * EtherTalk it might not fit
1359          *
1360          * Order matters here: If a packet has to be copied to make a new
1361          * headroom (rare hopefully) then it won't need unsharing.
1362          *
1363          * Note. ddp-> becomes invalid at the realloc.
1364          */
1365         if (skb_headroom(skb) < 22) {
1366                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1367                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1368                 kfree_skb(skb);
1369                 if (!nskb)
1370                         goto out;
1371                 skb = nskb;
1372         } else
1373                 skb = skb_unshare(skb, GFP_ATOMIC);
1374
1375         /*
1376          * If the buffer didn't vanish into the lack of space bitbucket we can
1377          * send it.
1378          */
1379         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1380                 goto free_it;
1381 out:
1382         return;
1383 free_it:
1384         kfree_skb(skb);
1385 }
1386
1387 /**
1388  *      atalk_rcv - Receive a packet (in skb) from device dev
1389  *      @skb - packet received
1390  *      @dev - network device where the packet comes from
1391  *      @pt - packet type
1392  *
1393  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1394  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1395  *      is the DDP header, skb->len is the DDP length. The physical headers
1396  *      have been extracted. PPP should probably pass frames marked as for this
1397  *      layer.  [ie ARPHRD_ETHERTALK]
1398  */
1399 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1400                      struct packet_type *pt, struct net_device *orig_dev)
1401 {
1402         struct ddpehdr *ddp;
1403         struct sock *sock;
1404         struct atalk_iface *atif;
1405         struct sockaddr_at tosat;
1406         int origlen;
1407         __u16 len_hops;
1408
1409         if (dev->nd_net != &init_net)
1410                 goto freeit;
1411
1412         /* Don't mangle buffer if shared */
1413         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1414                 goto out;
1415
1416         /* Size check and make sure header is contiguous */
1417         if (!pskb_may_pull(skb, sizeof(*ddp)))
1418                 goto freeit;
1419
1420         ddp = ddp_hdr(skb);
1421
1422         len_hops = ntohs(ddp->deh_len_hops);
1423
1424         /* Trim buffer in case of stray trailing data */
1425         origlen = skb->len;
1426         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1427
1428         /*
1429          * Size check to see if ddp->deh_len was crap
1430          * (Otherwise we'll detonate most spectacularly
1431          * in the middle of atalk_checksum() or recvmsg()).
1432          */
1433         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1434                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1435                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1436                 goto freeit;
1437         }
1438
1439         /*
1440          * Any checksums. Note we don't do htons() on this == is assumed to be
1441          * valid for net byte orders all over the networking code...
1442          */
1443         if (ddp->deh_sum &&
1444             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1445                 /* Not a valid AppleTalk frame - dustbin time */
1446                 goto freeit;
1447
1448         /* Check the packet is aimed at us */
1449         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1450                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1451         else
1452                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1453
1454         if (!atif) {
1455                 /* Not ours, so we route the packet via the correct
1456                  * AppleTalk iface
1457                  */
1458                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1459                 goto out;
1460         }
1461
1462         /* if IP over DDP is not selected this code will be optimized out */
1463         if (is_ip_over_ddp(skb))
1464                 return handle_ip_over_ddp(skb);
1465         /*
1466          * Which socket - atalk_search_socket() looks for a *full match*
1467          * of the <net, node, port> tuple.
1468          */
1469         tosat.sat_addr.s_net  = ddp->deh_dnet;
1470         tosat.sat_addr.s_node = ddp->deh_dnode;
1471         tosat.sat_port        = ddp->deh_dport;
1472
1473         sock = atalk_search_socket(&tosat, atif);
1474         if (!sock) /* But not one of our sockets */
1475                 goto freeit;
1476
1477         /* Queue packet (standard) */
1478         skb->sk = sock;
1479
1480         if (sock_queue_rcv_skb(sock, skb) < 0)
1481                 goto freeit;
1482 out:
1483         return 0;
1484 freeit:
1485         kfree_skb(skb);
1486         goto out;
1487 }
1488
1489 /*
1490  * Receive a LocalTalk frame. We make some demands on the caller here.
1491  * Caller must provide enough headroom on the packet to pull the short
1492  * header and append a long one.
1493  */
1494 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1495                      struct packet_type *pt, struct net_device *orig_dev)
1496 {
1497         if (dev->nd_net != &init_net)
1498                 goto freeit;
1499
1500         /* Expand any short form frames */
1501         if (skb_mac_header(skb)[2] == 1) {
1502                 struct ddpehdr *ddp;
1503                 /* Find our address */
1504                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1505
1506                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1507                         goto freeit;
1508
1509                 /* Don't mangle buffer if shared */
1510                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1511                         return 0;
1512
1513                 /*
1514                  * The push leaves us with a ddephdr not an shdr, and
1515                  * handily the port bytes in the right place preset.
1516                  */
1517                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1518
1519                 /* Now fill in the long header */
1520
1521                 /*
1522                  * These two first. The mac overlays the new source/dest
1523                  * network information so we MUST copy these before
1524                  * we write the network numbers !
1525                  */
1526
1527                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1528                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1529
1530                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1531                 ddp->deh_snet  = ap->s_net;
1532                 ddp->deh_sum   = 0;             /* No checksum */
1533                 /*
1534                  * Not sure about this bit...
1535                  */
1536                 /* Non routable, so force a drop if we slip up later */
1537                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1538         }
1539         skb_reset_transport_header(skb);
1540
1541         return atalk_rcv(skb, dev, pt, orig_dev);
1542 freeit:
1543         kfree_skb(skb);
1544         return 0;
1545 }
1546
1547 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1548                          size_t len)
1549 {
1550         struct sock *sk = sock->sk;
1551         struct atalk_sock *at = at_sk(sk);
1552         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1553         int flags = msg->msg_flags;
1554         int loopback = 0;
1555         struct sockaddr_at local_satalk, gsat;
1556         struct sk_buff *skb;
1557         struct net_device *dev;
1558         struct ddpehdr *ddp;
1559         int size;
1560         struct atalk_route *rt;
1561         int err;
1562
1563         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1564                 return -EINVAL;
1565
1566         if (len > DDP_MAXSZ)
1567                 return -EMSGSIZE;
1568
1569         if (usat) {
1570                 if (sock_flag(sk, SOCK_ZAPPED))
1571                         if (atalk_autobind(sk) < 0)
1572                                 return -EBUSY;
1573
1574                 if (msg->msg_namelen < sizeof(*usat) ||
1575                     usat->sat_family != AF_APPLETALK)
1576                         return -EINVAL;
1577
1578                 /* netatalk doesn't implement this check */
1579                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1580                     !sock_flag(sk, SOCK_BROADCAST)) {
1581                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1582                                          "it will break before 2.2\n");
1583 #if 0
1584                         return -EPERM;
1585 #endif
1586                 }
1587         } else {
1588                 if (sk->sk_state != TCP_ESTABLISHED)
1589                         return -ENOTCONN;
1590                 usat = &local_satalk;
1591                 usat->sat_family      = AF_APPLETALK;
1592                 usat->sat_port        = at->dest_port;
1593                 usat->sat_addr.s_node = at->dest_node;
1594                 usat->sat_addr.s_net  = at->dest_net;
1595         }
1596
1597         /* Build a packet */
1598         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1599
1600         /* For headers */
1601         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1602
1603         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1604                 rt = atrtr_find(&usat->sat_addr);
1605         } else {
1606                 struct atalk_addr at_hint;
1607
1608                 at_hint.s_node = 0;
1609                 at_hint.s_net  = at->src_net;
1610
1611                 rt = atrtr_find(&at_hint);
1612         }
1613         if (!rt)
1614                 return -ENETUNREACH;
1615
1616         dev = rt->dev;
1617
1618         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1619                         sk, size, dev->name);
1620
1621         size += dev->hard_header_len;
1622         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1623         if (!skb)
1624                 return err;
1625
1626         skb->sk = sk;
1627         skb_reserve(skb, ddp_dl->header_length);
1628         skb_reserve(skb, dev->hard_header_len);
1629         skb->dev = dev;
1630
1631         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1632
1633         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1634         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1635         ddp->deh_dnet  = usat->sat_addr.s_net;
1636         ddp->deh_snet  = at->src_net;
1637         ddp->deh_dnode = usat->sat_addr.s_node;
1638         ddp->deh_snode = at->src_node;
1639         ddp->deh_dport = usat->sat_port;
1640         ddp->deh_sport = at->src_port;
1641
1642         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1643
1644         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1645         if (err) {
1646                 kfree_skb(skb);
1647                 return -EFAULT;
1648         }
1649
1650         if (sk->sk_no_check == 1)
1651                 ddp->deh_sum = 0;
1652         else
1653                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1654
1655         /*
1656          * Loopback broadcast packets to non gateway targets (ie routes
1657          * to group we are in)
1658          */
1659         if (ddp->deh_dnode == ATADDR_BCAST &&
1660             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1661                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1662
1663                 if (skb2) {
1664                         loopback = 1;
1665                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1666                         if (aarp_send_ddp(dev, skb2,
1667                                           &usat->sat_addr, NULL) == -1)
1668                                 kfree_skb(skb2);
1669                                 /* else queued/sent above in the aarp queue */
1670                 }
1671         }
1672
1673         if (dev->flags & IFF_LOOPBACK || loopback) {
1674                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1675                 /* loop back */
1676                 skb_orphan(skb);
1677                 if (ddp->deh_dnode == ATADDR_BCAST) {
1678                         struct atalk_addr at_lo;
1679
1680                         at_lo.s_node = 0;
1681                         at_lo.s_net  = 0;
1682
1683                         rt = atrtr_find(&at_lo);
1684                         if (!rt) {
1685                                 kfree_skb(skb);
1686                                 return -ENETUNREACH;
1687                         }
1688                         dev = rt->dev;
1689                         skb->dev = dev;
1690                 }
1691                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1692         } else {
1693                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1694                 if (rt->flags & RTF_GATEWAY) {
1695                     gsat.sat_addr = rt->gateway;
1696                     usat = &gsat;
1697                 }
1698
1699                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1700                         kfree_skb(skb);
1701                 /* else queued/sent above in the aarp queue */
1702         }
1703         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1704
1705         return len;
1706 }
1707
1708 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1709                          size_t size, int flags)
1710 {
1711         struct sock *sk = sock->sk;
1712         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1713         struct ddpehdr *ddp;
1714         int copied = 0;
1715         int offset = 0;
1716         int err = 0;
1717         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1718                                                 flags & MSG_DONTWAIT, &err);
1719         if (!skb)
1720                 return err;
1721
1722         /* FIXME: use skb->cb to be able to use shared skbs */
1723         ddp = ddp_hdr(skb);
1724         copied = ntohs(ddp->deh_len_hops) & 1023;
1725
1726         if (sk->sk_type != SOCK_RAW) {
1727                 offset = sizeof(*ddp);
1728                 copied -= offset;
1729         }
1730
1731         if (copied > size) {
1732                 copied = size;
1733                 msg->msg_flags |= MSG_TRUNC;
1734         }
1735         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1736
1737         if (!err) {
1738                 if (sat) {
1739                         sat->sat_family      = AF_APPLETALK;
1740                         sat->sat_port        = ddp->deh_sport;
1741                         sat->sat_addr.s_node = ddp->deh_snode;
1742                         sat->sat_addr.s_net  = ddp->deh_snet;
1743                 }
1744                 msg->msg_namelen = sizeof(*sat);
1745         }
1746
1747         skb_free_datagram(sk, skb);     /* Free the datagram. */
1748         return err ? : copied;
1749 }
1750
1751
1752 /*
1753  * AppleTalk ioctl calls.
1754  */
1755 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1756 {
1757         int rc = -ENOIOCTLCMD;
1758         struct sock *sk = sock->sk;
1759         void __user *argp = (void __user *)arg;
1760
1761         switch (cmd) {
1762                 /* Protocol layer */
1763                 case TIOCOUTQ: {
1764                         long amount = sk->sk_sndbuf -
1765                                       atomic_read(&sk->sk_wmem_alloc);
1766
1767                         if (amount < 0)
1768                                 amount = 0;
1769                         rc = put_user(amount, (int __user *)argp);
1770                         break;
1771                 }
1772                 case TIOCINQ: {
1773                         /*
1774                          * These two are safe on a single CPU system as only
1775                          * user tasks fiddle here
1776                          */
1777                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1778                         long amount = 0;
1779
1780                         if (skb)
1781                                 amount = skb->len - sizeof(struct ddpehdr);
1782                         rc = put_user(amount, (int __user *)argp);
1783                         break;
1784                 }
1785                 case SIOCGSTAMP:
1786                         rc = sock_get_timestamp(sk, argp);
1787                         break;
1788                 case SIOCGSTAMPNS:
1789                         rc = sock_get_timestampns(sk, argp);
1790                         break;
1791                 /* Routing */
1792                 case SIOCADDRT:
1793                 case SIOCDELRT:
1794                         rc = -EPERM;
1795                         if (capable(CAP_NET_ADMIN))
1796                                 rc = atrtr_ioctl(cmd, argp);
1797                         break;
1798                 /* Interface */
1799                 case SIOCGIFADDR:
1800                 case SIOCSIFADDR:
1801                 case SIOCGIFBRDADDR:
1802                 case SIOCATALKDIFADDR:
1803                 case SIOCDIFADDR:
1804                 case SIOCSARP:          /* proxy AARP */
1805                 case SIOCDARP:          /* proxy AARP */
1806                         rtnl_lock();
1807                         rc = atif_ioctl(cmd, argp);
1808                         rtnl_unlock();
1809                         break;
1810         }
1811
1812         return rc;
1813 }
1814
1815
1816 #ifdef CONFIG_COMPAT
1817 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1818 {
1819         /*
1820          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1821          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1822          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1823          * here so there is no generic SIOCPROTOPRIVATE translation in the
1824          * system.
1825          */
1826         return -ENOIOCTLCMD;
1827 }
1828 #endif
1829
1830
1831 static struct net_proto_family atalk_family_ops = {
1832         .family         = PF_APPLETALK,
1833         .create         = atalk_create,
1834         .owner          = THIS_MODULE,
1835 };
1836
1837 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1838         .family         = PF_APPLETALK,
1839         .owner          = THIS_MODULE,
1840         .release        = atalk_release,
1841         .bind           = atalk_bind,
1842         .connect        = atalk_connect,
1843         .socketpair     = sock_no_socketpair,
1844         .accept         = sock_no_accept,
1845         .getname        = atalk_getname,
1846         .poll           = datagram_poll,
1847         .ioctl          = atalk_ioctl,
1848 #ifdef CONFIG_COMPAT
1849         .compat_ioctl   = atalk_compat_ioctl,
1850 #endif
1851         .listen         = sock_no_listen,
1852         .shutdown       = sock_no_shutdown,
1853         .setsockopt     = sock_no_setsockopt,
1854         .getsockopt     = sock_no_getsockopt,
1855         .sendmsg        = atalk_sendmsg,
1856         .recvmsg        = atalk_recvmsg,
1857         .mmap           = sock_no_mmap,
1858         .sendpage       = sock_no_sendpage,
1859 };
1860
1861 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1862
1863 static struct notifier_block ddp_notifier = {
1864         .notifier_call  = ddp_device_event,
1865 };
1866
1867 static struct packet_type ltalk_packet_type = {
1868         .type           = __constant_htons(ETH_P_LOCALTALK),
1869         .func           = ltalk_rcv,
1870 };
1871
1872 static struct packet_type ppptalk_packet_type = {
1873         .type           = __constant_htons(ETH_P_PPPTALK),
1874         .func           = atalk_rcv,
1875 };
1876
1877 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1878
1879 /* Export symbols for use by drivers when AppleTalk is a module */
1880 EXPORT_SYMBOL(aarp_send_ddp);
1881 EXPORT_SYMBOL(atrtr_get_dev);
1882 EXPORT_SYMBOL(atalk_find_dev_addr);
1883
1884 static char atalk_err_snap[] __initdata =
1885         KERN_CRIT "Unable to register DDP with SNAP.\n";
1886
1887 /* Called by proto.c on kernel start up */
1888 static int __init atalk_init(void)
1889 {
1890         int rc = proto_register(&ddp_proto, 0);
1891
1892         if (rc != 0)
1893                 goto out;
1894
1895         (void)sock_register(&atalk_family_ops);
1896         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1897         if (!ddp_dl)
1898                 printk(atalk_err_snap);
1899
1900         dev_add_pack(&ltalk_packet_type);
1901         dev_add_pack(&ppptalk_packet_type);
1902
1903         register_netdevice_notifier(&ddp_notifier);
1904         aarp_proto_init();
1905         atalk_proc_init();
1906         atalk_register_sysctl();
1907 out:
1908         return rc;
1909 }
1910 module_init(atalk_init);
1911
1912 /*
1913  * No explicit module reference count manipulation is needed in the
1914  * protocol. Socket layer sets module reference count for us
1915  * and interfaces reference counting is done
1916  * by the network device layer.
1917  *
1918  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1919  * sockets be closed from user space.
1920  */
1921 static void __exit atalk_exit(void)
1922 {
1923 #ifdef CONFIG_SYSCTL
1924         atalk_unregister_sysctl();
1925 #endif /* CONFIG_SYSCTL */
1926         atalk_proc_exit();
1927         aarp_cleanup_module();  /* General aarp clean-up. */
1928         unregister_netdevice_notifier(&ddp_notifier);
1929         dev_remove_pack(&ltalk_packet_type);
1930         dev_remove_pack(&ppptalk_packet_type);
1931         unregister_snap_client(ddp_dl);
1932         sock_unregister(PF_APPLETALK);
1933         proto_unregister(&ddp_proto);
1934 }
1935 module_exit(atalk_exit);
1936
1937 MODULE_LICENSE("GPL");
1938 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1939 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1940 MODULE_ALIAS_NETPROTO(PF_APPLETALK);