206e771e82d17ce77b7c99447f12437f4fd300c5
[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@lxorguk.ukuu.org.uk>
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 <linux/compat.h>
59 #include <linux/slab.h>
60 #include <net/datalink.h>
61 #include <net/psnap.h>
62 #include <net/sock.h>
63 #include <net/tcp_states.h>
64 #include <net/route.h>
65 #include <linux/atalk.h>
66 #include "../core/kmap_skb.h"
67
68 struct datalink_proto *ddp_dl, *aarp_dl;
69 static const struct proto_ops atalk_dgram_ops;
70
71 /**************************************************************************\
72 *                                                                          *
73 * Handlers for the socket list.                                            *
74 *                                                                          *
75 \**************************************************************************/
76
77 HLIST_HEAD(atalk_sockets);
78 DEFINE_RWLOCK(atalk_sockets_lock);
79
80 static inline void __atalk_insert_socket(struct sock *sk)
81 {
82         sk_add_node(sk, &atalk_sockets);
83 }
84
85 static inline void atalk_remove_socket(struct sock *sk)
86 {
87         write_lock_bh(&atalk_sockets_lock);
88         sk_del_node_init(sk);
89         write_unlock_bh(&atalk_sockets_lock);
90 }
91
92 static struct sock *atalk_search_socket(struct sockaddr_at *to,
93                                         struct atalk_iface *atif)
94 {
95         struct sock *s;
96         struct hlist_node *node;
97
98         read_lock_bh(&atalk_sockets_lock);
99         sk_for_each(s, node, &atalk_sockets) {
100                 struct atalk_sock *at = at_sk(s);
101
102                 if (to->sat_port != at->src_port)
103                         continue;
104
105                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
106                     to->sat_addr.s_node == ATADDR_BCAST)
107                         goto found;
108
109                 if (to->sat_addr.s_net == at->src_net &&
110                     (to->sat_addr.s_node == at->src_node ||
111                      to->sat_addr.s_node == ATADDR_BCAST ||
112                      to->sat_addr.s_node == ATADDR_ANYNODE))
113                         goto found;
114
115                 /* XXXX.0 -- we got a request for this router. make sure
116                  * that the node is appropriately set. */
117                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
118                     to->sat_addr.s_net != ATADDR_ANYNET &&
119                     atif->address.s_node == at->src_node) {
120                         to->sat_addr.s_node = atif->address.s_node;
121                         goto found;
122                 }
123         }
124         s = NULL;
125 found:
126         read_unlock_bh(&atalk_sockets_lock);
127         return s;
128 }
129
130 /**
131  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
132  * @sk - socket to insert in the list if it is not there already
133  * @sat - address to search for
134  *
135  * Try to find a socket matching ADDR in the socket list, if found then return
136  * it. If not, insert SK into the socket list.
137  *
138  * This entire operation must execute atomically.
139  */
140 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
141                                                 struct sockaddr_at *sat)
142 {
143         struct sock *s;
144         struct hlist_node *node;
145         struct atalk_sock *at;
146
147         write_lock_bh(&atalk_sockets_lock);
148         sk_for_each(s, node, &atalk_sockets) {
149                 at = at_sk(s);
150
151                 if (at->src_net == sat->sat_addr.s_net &&
152                     at->src_node == sat->sat_addr.s_node &&
153                     at->src_port == sat->sat_port)
154                         goto found;
155         }
156         s = NULL;
157         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
158 found:
159         write_unlock_bh(&atalk_sockets_lock);
160         return s;
161 }
162
163 static void atalk_destroy_timer(unsigned long data)
164 {
165         struct sock *sk = (struct sock *)data;
166
167         if (sk_has_allocations(sk)) {
168                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
169                 add_timer(&sk->sk_timer);
170         } else
171                 sock_put(sk);
172 }
173
174 static inline void atalk_destroy_socket(struct sock *sk)
175 {
176         atalk_remove_socket(sk);
177         skb_queue_purge(&sk->sk_receive_queue);
178
179         if (sk_has_allocations(sk)) {
180                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
181                                 (unsigned long)sk);
182                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
183                 add_timer(&sk->sk_timer);
184         } else
185                 sock_put(sk);
186 }
187
188 /**************************************************************************\
189 *                                                                          *
190 * Routing tables for the AppleTalk socket layer.                           *
191 *                                                                          *
192 \**************************************************************************/
193
194 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
195 struct atalk_route *atalk_routes;
196 DEFINE_RWLOCK(atalk_routes_lock);
197
198 struct atalk_iface *atalk_interfaces;
199 DEFINE_RWLOCK(atalk_interfaces_lock);
200
201 /* For probing devices or in a routerless network */
202 struct atalk_route atrtr_default;
203
204 /* AppleTalk interface control */
205 /*
206  * Drop a device. Doesn't drop any of its routes - that is the caller's
207  * problem. Called when we down the interface or delete the address.
208  */
209 static void atif_drop_device(struct net_device *dev)
210 {
211         struct atalk_iface **iface = &atalk_interfaces;
212         struct atalk_iface *tmp;
213
214         write_lock_bh(&atalk_interfaces_lock);
215         while ((tmp = *iface) != NULL) {
216                 if (tmp->dev == dev) {
217                         *iface = tmp->next;
218                         dev_put(dev);
219                         kfree(tmp);
220                         dev->atalk_ptr = NULL;
221                 } else
222                         iface = &tmp->next;
223         }
224         write_unlock_bh(&atalk_interfaces_lock);
225 }
226
227 static struct atalk_iface *atif_add_device(struct net_device *dev,
228                                            struct atalk_addr *sa)
229 {
230         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
231
232         if (!iface)
233                 goto out;
234
235         dev_hold(dev);
236         iface->dev = dev;
237         dev->atalk_ptr = iface;
238         iface->address = *sa;
239         iface->status = 0;
240
241         write_lock_bh(&atalk_interfaces_lock);
242         iface->next = atalk_interfaces;
243         atalk_interfaces = iface;
244         write_unlock_bh(&atalk_interfaces_lock);
245 out:
246         return iface;
247 }
248
249 /* Perform phase 2 AARP probing on our tentative address */
250 static int atif_probe_device(struct atalk_iface *atif)
251 {
252         int netrange = ntohs(atif->nets.nr_lastnet) -
253                         ntohs(atif->nets.nr_firstnet) + 1;
254         int probe_net = ntohs(atif->address.s_net);
255         int probe_node = atif->address.s_node;
256         int netct, nodect;
257
258         /* Offset the network we start probing with */
259         if (probe_net == ATADDR_ANYNET) {
260                 probe_net = ntohs(atif->nets.nr_firstnet);
261                 if (netrange)
262                         probe_net += jiffies % netrange;
263         }
264         if (probe_node == ATADDR_ANYNODE)
265                 probe_node = jiffies & 0xFF;
266
267         /* Scan the networks */
268         atif->status |= ATIF_PROBE;
269         for (netct = 0; netct <= netrange; netct++) {
270                 /* Sweep the available nodes from a given start */
271                 atif->address.s_net = htons(probe_net);
272                 for (nodect = 0; nodect < 256; nodect++) {
273                         atif->address.s_node = (nodect + probe_node) & 0xFF;
274                         if (atif->address.s_node > 0 &&
275                             atif->address.s_node < 254) {
276                                 /* Probe a proposed address */
277                                 aarp_probe_network(atif);
278
279                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
280                                         atif->status &= ~ATIF_PROBE;
281                                         return 0;
282                                 }
283                         }
284                         atif->status &= ~ATIF_PROBE_FAIL;
285                 }
286                 probe_net++;
287                 if (probe_net > ntohs(atif->nets.nr_lastnet))
288                         probe_net = ntohs(atif->nets.nr_firstnet);
289         }
290         atif->status &= ~ATIF_PROBE;
291
292         return -EADDRINUSE;     /* Network is full... */
293 }
294
295
296 /* Perform AARP probing for a proxy address */
297 static int atif_proxy_probe_device(struct atalk_iface *atif,
298                                    struct atalk_addr* proxy_addr)
299 {
300         int netrange = ntohs(atif->nets.nr_lastnet) -
301                         ntohs(atif->nets.nr_firstnet) + 1;
302         /* we probe the interface's network */
303         int probe_net = ntohs(atif->address.s_net);
304         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
305         int netct, nodect;
306
307         /* Offset the network we start probing with */
308         if (probe_net == ATADDR_ANYNET) {
309                 probe_net = ntohs(atif->nets.nr_firstnet);
310                 if (netrange)
311                         probe_net += jiffies % netrange;
312         }
313
314         if (probe_node == ATADDR_ANYNODE)
315                 probe_node = jiffies & 0xFF;
316
317         /* Scan the networks */
318         for (netct = 0; netct <= netrange; netct++) {
319                 /* Sweep the available nodes from a given start */
320                 proxy_addr->s_net = htons(probe_net);
321                 for (nodect = 0; nodect < 256; nodect++) {
322                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
323                         if (proxy_addr->s_node > 0 &&
324                             proxy_addr->s_node < 254) {
325                                 /* Tell AARP to probe a proposed address */
326                                 int ret = aarp_proxy_probe_network(atif,
327                                                                     proxy_addr);
328
329                                 if (ret != -EADDRINUSE)
330                                         return ret;
331                         }
332                 }
333                 probe_net++;
334                 if (probe_net > ntohs(atif->nets.nr_lastnet))
335                         probe_net = ntohs(atif->nets.nr_firstnet);
336         }
337
338         return -EADDRINUSE;     /* Network is full... */
339 }
340
341
342 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
343 {
344         struct atalk_iface *iface = dev->atalk_ptr;
345         return iface ? &iface->address : NULL;
346 }
347
348 static struct atalk_addr *atalk_find_primary(void)
349 {
350         struct atalk_iface *fiface = NULL;
351         struct atalk_addr *retval;
352         struct atalk_iface *iface;
353
354         /*
355          * Return a point-to-point interface only if
356          * there is no non-ptp interface available.
357          */
358         read_lock_bh(&atalk_interfaces_lock);
359         for (iface = atalk_interfaces; iface; iface = iface->next) {
360                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
361                         fiface = iface;
362                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
363                         retval = &iface->address;
364                         goto out;
365                 }
366         }
367
368         if (fiface)
369                 retval = &fiface->address;
370         else if (atalk_interfaces)
371                 retval = &atalk_interfaces->address;
372         else
373                 retval = NULL;
374 out:
375         read_unlock_bh(&atalk_interfaces_lock);
376         return retval;
377 }
378
379 /*
380  * Find a match for 'any network' - ie any of our interfaces with that
381  * node number will do just nicely.
382  */
383 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
384 {
385         struct atalk_iface *iface = dev->atalk_ptr;
386
387         if (!iface || iface->status & ATIF_PROBE)
388                 goto out_err;
389
390         if (node != ATADDR_BCAST &&
391             iface->address.s_node != node &&
392             node != ATADDR_ANYNODE)
393                 goto out_err;
394 out:
395         return iface;
396 out_err:
397         iface = NULL;
398         goto out;
399 }
400
401 /* Find a match for a specific network:node pair */
402 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
403 {
404         struct atalk_iface *iface;
405
406         read_lock_bh(&atalk_interfaces_lock);
407         for (iface = atalk_interfaces; iface; iface = iface->next) {
408                 if ((node == ATADDR_BCAST ||
409                      node == ATADDR_ANYNODE ||
410                      iface->address.s_node == node) &&
411                     iface->address.s_net == net &&
412                     !(iface->status & ATIF_PROBE))
413                         break;
414
415                 /* XXXX.0 -- net.0 returns the iface associated with net */
416                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
417                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
418                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
419                         break;
420         }
421         read_unlock_bh(&atalk_interfaces_lock);
422         return iface;
423 }
424
425
426 /*
427  * Find a route for an AppleTalk packet. This ought to get cached in
428  * the socket (later on...). We know about host routes and the fact
429  * that a route must be direct to broadcast.
430  */
431 static struct atalk_route *atrtr_find(struct atalk_addr *target)
432 {
433         /*
434          * we must search through all routes unless we find a
435          * host route, because some host routes might overlap
436          * network routes
437          */
438         struct atalk_route *net_route = NULL;
439         struct atalk_route *r;
440
441         read_lock_bh(&atalk_routes_lock);
442         for (r = atalk_routes; r; r = r->next) {
443                 if (!(r->flags & RTF_UP))
444                         continue;
445
446                 if (r->target.s_net == target->s_net) {
447                         if (r->flags & RTF_HOST) {
448                                 /*
449                                  * if this host route is for the target,
450                                  * the we're done
451                                  */
452                                 if (r->target.s_node == target->s_node)
453                                         goto out;
454                         } else
455                                 /*
456                                  * this route will work if there isn't a
457                                  * direct host route, so cache it
458                                  */
459                                 net_route = r;
460                 }
461         }
462
463         /*
464          * if we found a network route but not a direct host
465          * route, then return it
466          */
467         if (net_route)
468                 r = net_route;
469         else if (atrtr_default.dev)
470                 r = &atrtr_default;
471         else /* No route can be found */
472                 r = NULL;
473 out:
474         read_unlock_bh(&atalk_routes_lock);
475         return r;
476 }
477
478
479 /*
480  * Given an AppleTalk network, find the device to use. This can be
481  * a simple lookup.
482  */
483 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
484 {
485         struct atalk_route *atr = atrtr_find(sa);
486         return atr ? atr->dev : NULL;
487 }
488
489 /* Set up a default router */
490 static void atrtr_set_default(struct net_device *dev)
491 {
492         atrtr_default.dev            = dev;
493         atrtr_default.flags          = RTF_UP;
494         atrtr_default.gateway.s_net  = htons(0);
495         atrtr_default.gateway.s_node = 0;
496 }
497
498 /*
499  * Add a router. Basically make sure it looks valid and stuff the
500  * entry in the list. While it uses netranges we always set them to one
501  * entry to work like netatalk.
502  */
503 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
504 {
505         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
506         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
507         struct atalk_route *rt;
508         struct atalk_iface *iface, *riface;
509         int retval = -EINVAL;
510
511         /*
512          * Fixme: Raise/Lower a routing change semaphore for these
513          * operations.
514          */
515
516         /* Validate the request */
517         if (ta->sat_family != AF_APPLETALK ||
518             (!devhint && ga->sat_family != AF_APPLETALK))
519                 goto out;
520
521         /* Now walk the routing table and make our decisions */
522         write_lock_bh(&atalk_routes_lock);
523         for (rt = atalk_routes; rt; rt = rt->next) {
524                 if (r->rt_flags != rt->flags)
525                         continue;
526
527                 if (ta->sat_addr.s_net == rt->target.s_net) {
528                         if (!(rt->flags & RTF_HOST))
529                                 break;
530                         if (ta->sat_addr.s_node == rt->target.s_node)
531                                 break;
532                 }
533         }
534
535         if (!devhint) {
536                 riface = NULL;
537
538                 read_lock_bh(&atalk_interfaces_lock);
539                 for (iface = atalk_interfaces; iface; iface = iface->next) {
540                         if (!riface &&
541                             ntohs(ga->sat_addr.s_net) >=
542                                         ntohs(iface->nets.nr_firstnet) &&
543                             ntohs(ga->sat_addr.s_net) <=
544                                         ntohs(iface->nets.nr_lastnet))
545                                 riface = iface;
546
547                         if (ga->sat_addr.s_net == iface->address.s_net &&
548                             ga->sat_addr.s_node == iface->address.s_node)
549                                 riface = iface;
550                 }
551                 read_unlock_bh(&atalk_interfaces_lock);
552
553                 retval = -ENETUNREACH;
554                 if (!riface)
555                         goto out_unlock;
556
557                 devhint = riface->dev;
558         }
559
560         if (!rt) {
561                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
562
563                 retval = -ENOBUFS;
564                 if (!rt)
565                         goto out_unlock;
566
567                 rt->next = atalk_routes;
568                 atalk_routes = rt;
569         }
570
571         /* Fill in the routing entry */
572         rt->target  = ta->sat_addr;
573         dev_hold(devhint);
574         rt->dev     = devhint;
575         rt->flags   = r->rt_flags;
576         rt->gateway = ga->sat_addr;
577
578         retval = 0;
579 out_unlock:
580         write_unlock_bh(&atalk_routes_lock);
581 out:
582         return retval;
583 }
584
585 /* Delete a route. Find it and discard it */
586 static int atrtr_delete(struct atalk_addr * addr)
587 {
588         struct atalk_route **r = &atalk_routes;
589         int retval = 0;
590         struct atalk_route *tmp;
591
592         write_lock_bh(&atalk_routes_lock);
593         while ((tmp = *r) != NULL) {
594                 if (tmp->target.s_net == addr->s_net &&
595                     (!(tmp->flags&RTF_GATEWAY) ||
596                      tmp->target.s_node == addr->s_node)) {
597                         *r = tmp->next;
598                         dev_put(tmp->dev);
599                         kfree(tmp);
600                         goto out;
601                 }
602                 r = &tmp->next;
603         }
604         retval = -ENOENT;
605 out:
606         write_unlock_bh(&atalk_routes_lock);
607         return retval;
608 }
609
610 /*
611  * Called when a device is downed. Just throw away any routes
612  * via it.
613  */
614 static void atrtr_device_down(struct net_device *dev)
615 {
616         struct atalk_route **r = &atalk_routes;
617         struct atalk_route *tmp;
618
619         write_lock_bh(&atalk_routes_lock);
620         while ((tmp = *r) != NULL) {
621                 if (tmp->dev == dev) {
622                         *r = tmp->next;
623                         dev_put(dev);
624                         kfree(tmp);
625                 } else
626                         r = &tmp->next;
627         }
628         write_unlock_bh(&atalk_routes_lock);
629
630         if (atrtr_default.dev == dev)
631                 atrtr_set_default(NULL);
632 }
633
634 /* Actually down the interface */
635 static inline void atalk_dev_down(struct net_device *dev)
636 {
637         atrtr_device_down(dev); /* Remove all routes for the device */
638         aarp_device_down(dev);  /* Remove AARP entries for the device */
639         atif_drop_device(dev);  /* Remove the device */
640 }
641
642 /*
643  * A device event has occurred. Watch for devices going down and
644  * delete our use of them (iface and route).
645  */
646 static int ddp_device_event(struct notifier_block *this, unsigned long event,
647                             void *ptr)
648 {
649         struct net_device *dev = ptr;
650
651         if (!net_eq(dev_net(dev), &init_net))
652                 return NOTIFY_DONE;
653
654         if (event == NETDEV_DOWN)
655                 /* Discard any use of this */
656                 atalk_dev_down(dev);
657
658         return NOTIFY_DONE;
659 }
660
661 /* ioctl calls. Shouldn't even need touching */
662 /* Device configuration ioctl calls */
663 static int atif_ioctl(int cmd, void __user *arg)
664 {
665         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
666         struct ifreq atreq;
667         struct atalk_netrange *nr;
668         struct sockaddr_at *sa;
669         struct net_device *dev;
670         struct atalk_iface *atif;
671         int ct;
672         int limit;
673         struct rtentry rtdef;
674         int add_route;
675
676         if (copy_from_user(&atreq, arg, sizeof(atreq)))
677                 return -EFAULT;
678
679         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
680         if (!dev)
681                 return -ENODEV;
682
683         sa = (struct sockaddr_at *)&atreq.ifr_addr;
684         atif = atalk_find_dev(dev);
685
686         switch (cmd) {
687                 case SIOCSIFADDR:
688                         if (!capable(CAP_NET_ADMIN))
689                                 return -EPERM;
690                         if (sa->sat_family != AF_APPLETALK)
691                                 return -EINVAL;
692                         if (dev->type != ARPHRD_ETHER &&
693                             dev->type != ARPHRD_LOOPBACK &&
694                             dev->type != ARPHRD_LOCALTLK &&
695                             dev->type != ARPHRD_PPP)
696                                 return -EPROTONOSUPPORT;
697
698                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
699                         add_route = 1;
700
701                         /*
702                          * if this is a point-to-point iface, and we already
703                          * have an iface for this AppleTalk address, then we
704                          * should not add a route
705                          */
706                         if ((dev->flags & IFF_POINTOPOINT) &&
707                             atalk_find_interface(sa->sat_addr.s_net,
708                                                  sa->sat_addr.s_node)) {
709                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
710                                                   "interface added with "
711                                                   "existing address\n");
712                                 add_route = 0;
713                         }
714
715                         /*
716                          * Phase 1 is fine on LocalTalk but we don't do
717                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
718                          */
719                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
720                                 return -EPROTONOSUPPORT;
721                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
722                             sa->sat_addr.s_node == 254)
723                                 return -EINVAL;
724                         if (atif) {
725                                 /* Already setting address */
726                                 if (atif->status & ATIF_PROBE)
727                                         return -EBUSY;
728
729                                 atif->address.s_net  = sa->sat_addr.s_net;
730                                 atif->address.s_node = sa->sat_addr.s_node;
731                                 atrtr_device_down(dev); /* Flush old routes */
732                         } else {
733                                 atif = atif_add_device(dev, &sa->sat_addr);
734                                 if (!atif)
735                                         return -ENOMEM;
736                         }
737                         atif->nets = *nr;
738
739                         /*
740                          * Check if the chosen address is used. If so we
741                          * error and atalkd will try another.
742                          */
743
744                         if (!(dev->flags & IFF_LOOPBACK) &&
745                             !(dev->flags & IFF_POINTOPOINT) &&
746                             atif_probe_device(atif) < 0) {
747                                 atif_drop_device(dev);
748                                 return -EADDRINUSE;
749                         }
750
751                         /* Hey it worked - add the direct routes */
752                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
753                         sa->sat_family = AF_APPLETALK;
754                         sa->sat_addr.s_net  = atif->address.s_net;
755                         sa->sat_addr.s_node = atif->address.s_node;
756                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
757                         rtdef.rt_flags = RTF_UP;
758                         sa->sat_family = AF_APPLETALK;
759                         sa->sat_addr.s_node = ATADDR_ANYNODE;
760                         if (dev->flags & IFF_LOOPBACK ||
761                             dev->flags & IFF_POINTOPOINT)
762                                 rtdef.rt_flags |= RTF_HOST;
763
764                         /* Routerless initial state */
765                         if (nr->nr_firstnet == htons(0) &&
766                             nr->nr_lastnet == htons(0xFFFE)) {
767                                 sa->sat_addr.s_net = atif->address.s_net;
768                                 atrtr_create(&rtdef, dev);
769                                 atrtr_set_default(dev);
770                         } else {
771                                 limit = ntohs(nr->nr_lastnet);
772                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
773                                         printk(KERN_WARNING "Too many routes/"
774                                                             "iface.\n");
775                                         return -EINVAL;
776                                 }
777                                 if (add_route)
778                                         for (ct = ntohs(nr->nr_firstnet);
779                                              ct <= limit; ct++) {
780                                                 sa->sat_addr.s_net = htons(ct);
781                                                 atrtr_create(&rtdef, dev);
782                                         }
783                         }
784                         dev_mc_add_global(dev, aarp_mcast);
785                         return 0;
786
787                 case SIOCGIFADDR:
788                         if (!atif)
789                                 return -EADDRNOTAVAIL;
790
791                         sa->sat_family = AF_APPLETALK;
792                         sa->sat_addr = atif->address;
793                         break;
794
795                 case SIOCGIFBRDADDR:
796                         if (!atif)
797                                 return -EADDRNOTAVAIL;
798
799                         sa->sat_family = AF_APPLETALK;
800                         sa->sat_addr.s_net = atif->address.s_net;
801                         sa->sat_addr.s_node = ATADDR_BCAST;
802                         break;
803
804                 case SIOCATALKDIFADDR:
805                 case SIOCDIFADDR:
806                         if (!capable(CAP_NET_ADMIN))
807                                 return -EPERM;
808                         if (sa->sat_family != AF_APPLETALK)
809                                 return -EINVAL;
810                         atalk_dev_down(dev);
811                         break;
812
813                 case SIOCSARP:
814                         if (!capable(CAP_NET_ADMIN))
815                                 return -EPERM;
816                         if (sa->sat_family != AF_APPLETALK)
817                                 return -EINVAL;
818                         /*
819                          * for now, we only support proxy AARP on ELAP;
820                          * we should be able to do it for LocalTalk, too.
821                          */
822                         if (dev->type != ARPHRD_ETHER)
823                                 return -EPROTONOSUPPORT;
824
825                         /*
826                          * atif points to the current interface on this network;
827                          * we aren't concerned about its current status (at
828                          * least for now), but it has all the settings about
829                          * the network we're going to probe. Consequently, it
830                          * must exist.
831                          */
832                         if (!atif)
833                                 return -EADDRNOTAVAIL;
834
835                         nr = (struct atalk_netrange *)&(atif->nets);
836                         /*
837                          * Phase 1 is fine on Localtalk but we don't do
838                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
839                          */
840                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
841                                 return -EPROTONOSUPPORT;
842
843                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
844                             sa->sat_addr.s_node == 254)
845                                 return -EINVAL;
846
847                         /*
848                          * Check if the chosen address is used. If so we
849                          * error and ATCP will try another.
850                          */
851                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
852                                 return -EADDRINUSE;
853
854                         /*
855                          * We now have an address on the local network, and
856                          * the AARP code will defend it for us until we take it
857                          * down. We don't set up any routes right now, because
858                          * ATCP will install them manually via SIOCADDRT.
859                          */
860                         break;
861
862                 case SIOCDARP:
863                         if (!capable(CAP_NET_ADMIN))
864                                 return -EPERM;
865                         if (sa->sat_family != AF_APPLETALK)
866                                 return -EINVAL;
867                         if (!atif)
868                                 return -EADDRNOTAVAIL;
869
870                         /* give to aarp module to remove proxy entry */
871                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
872                         return 0;
873         }
874
875         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
876 }
877
878 /* Routing ioctl() calls */
879 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
880 {
881         struct rtentry rt;
882
883         if (copy_from_user(&rt, arg, sizeof(rt)))
884                 return -EFAULT;
885
886         switch (cmd) {
887                 case SIOCDELRT:
888                         if (rt.rt_dst.sa_family != AF_APPLETALK)
889                                 return -EINVAL;
890                         return atrtr_delete(&((struct sockaddr_at *)
891                                                 &rt.rt_dst)->sat_addr);
892
893                 case SIOCADDRT: {
894                         struct net_device *dev = NULL;
895                         if (rt.rt_dev) {
896                                 char name[IFNAMSIZ];
897                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
898                                         return -EFAULT;
899                                 name[IFNAMSIZ-1] = '\0';
900                                 dev = __dev_get_by_name(&init_net, name);
901                                 if (!dev)
902                                         return -ENODEV;
903                         }
904                         return atrtr_create(&rt, dev);
905                 }
906         }
907         return -EINVAL;
908 }
909
910 /**************************************************************************\
911 *                                                                          *
912 * Handling for system calls applied via the various interfaces to an       *
913 * AppleTalk socket object.                                                 *
914 *                                                                          *
915 \**************************************************************************/
916
917 /*
918  * Checksum: This is 'optional'. It's quite likely also a good
919  * candidate for assembler hackery 8)
920  */
921 static unsigned long atalk_sum_partial(const unsigned char *data,
922                                        int len, unsigned long sum)
923 {
924         /* This ought to be unwrapped neatly. I'll trust gcc for now */
925         while (len--) {
926                 sum += *data++;
927                 sum = rol16(sum, 1);
928         }
929         return sum;
930 }
931
932 /*  Checksum skb data --  similar to skb_checksum  */
933 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
934                                    int len, unsigned long sum)
935 {
936         int start = skb_headlen(skb);
937         struct sk_buff *frag_iter;
938         int i, copy;
939
940         /* checksum stuff in header space */
941         if ( (copy = start - offset) > 0) {
942                 if (copy > len)
943                         copy = len;
944                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
945                 if ( (len -= copy) == 0)
946                         return sum;
947
948                 offset += copy;
949         }
950
951         /* checksum stuff in frags */
952         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
953                 int end;
954
955                 WARN_ON(start > offset + len);
956
957                 end = start + skb_shinfo(skb)->frags[i].size;
958                 if ((copy = end - offset) > 0) {
959                         u8 *vaddr;
960                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
961
962                         if (copy > len)
963                                 copy = len;
964                         vaddr = kmap_skb_frag(frag);
965                         sum = atalk_sum_partial(vaddr + frag->page_offset +
966                                                   offset - start, copy, sum);
967                         kunmap_skb_frag(vaddr);
968
969                         if (!(len -= copy))
970                                 return sum;
971                         offset += copy;
972                 }
973                 start = end;
974         }
975
976         skb_walk_frags(skb, frag_iter) {
977                 int end;
978
979                 WARN_ON(start > offset + len);
980
981                 end = start + frag_iter->len;
982                 if ((copy = end - offset) > 0) {
983                         if (copy > len)
984                                 copy = len;
985                         sum = atalk_sum_skb(frag_iter, offset - start,
986                                             copy, sum);
987                         if ((len -= copy) == 0)
988                                 return sum;
989                         offset += copy;
990                 }
991                 start = end;
992         }
993
994         BUG_ON(len > 0);
995
996         return sum;
997 }
998
999 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1000 {
1001         unsigned long sum;
1002
1003         /* skip header 4 bytes */
1004         sum = atalk_sum_skb(skb, 4, len-4, 0);
1005
1006         /* Use 0xFFFF for 0. 0 itself means none */
1007         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1008 }
1009
1010 static struct proto ddp_proto = {
1011         .name     = "DDP",
1012         .owner    = THIS_MODULE,
1013         .obj_size = sizeof(struct atalk_sock),
1014 };
1015
1016 /*
1017  * Create a socket. Initialise the socket, blank the addresses
1018  * set the state.
1019  */
1020 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1021                         int kern)
1022 {
1023         struct sock *sk;
1024         int rc = -ESOCKTNOSUPPORT;
1025
1026         if (!net_eq(net, &init_net))
1027                 return -EAFNOSUPPORT;
1028
1029         /*
1030          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1031          * and gives you the full ELAP frame. Should be handy for CAP 8)
1032          */
1033         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1034                 goto out;
1035         rc = -ENOMEM;
1036         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1037         if (!sk)
1038                 goto out;
1039         rc = 0;
1040         sock->ops = &atalk_dgram_ops;
1041         sock_init_data(sock, sk);
1042
1043         /* Checksums on by default */
1044         sock_set_flag(sk, SOCK_ZAPPED);
1045 out:
1046         return rc;
1047 }
1048
1049 /* Free a socket. No work needed */
1050 static int atalk_release(struct socket *sock)
1051 {
1052         struct sock *sk = sock->sk;
1053
1054         sock_hold(sk);
1055         lock_sock(sk);
1056         if (sk) {
1057                 sock_orphan(sk);
1058                 sock->sk = NULL;
1059                 atalk_destroy_socket(sk);
1060         }
1061         release_sock(sk);
1062         sock_put(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         int err;
1140
1141         if (!sock_flag(sk, SOCK_ZAPPED) ||
1142             addr_len != sizeof(struct sockaddr_at))
1143                 return -EINVAL;
1144
1145         if (addr->sat_family != AF_APPLETALK)
1146                 return -EAFNOSUPPORT;
1147
1148         lock_sock(sk);
1149         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1150                 struct atalk_addr *ap = atalk_find_primary();
1151
1152                 err = -EADDRNOTAVAIL;
1153                 if (!ap)
1154                         goto out;
1155
1156                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1157                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1158         } else {
1159                 err = -EADDRNOTAVAIL;
1160                 if (!atalk_find_interface(addr->sat_addr.s_net,
1161                                           addr->sat_addr.s_node))
1162                         goto out;
1163
1164                 at->src_net  = addr->sat_addr.s_net;
1165                 at->src_node = addr->sat_addr.s_node;
1166         }
1167
1168         if (addr->sat_port == ATADDR_ANYPORT) {
1169                 err = atalk_pick_and_bind_port(sk, addr);
1170
1171                 if (err < 0)
1172                         goto out;
1173         } else {
1174                 at->src_port = addr->sat_port;
1175
1176                 err = -EADDRINUSE;
1177                 if (atalk_find_or_insert_socket(sk, addr))
1178                         goto out;
1179         }
1180
1181         sock_reset_flag(sk, SOCK_ZAPPED);
1182         err = 0;
1183 out:
1184         release_sock(sk);
1185         return err;
1186 }
1187
1188 /* Set the address we talk to */
1189 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1190                          int addr_len, int flags)
1191 {
1192         struct sock *sk = sock->sk;
1193         struct atalk_sock *at = at_sk(sk);
1194         struct sockaddr_at *addr;
1195         int err;
1196
1197         sk->sk_state   = TCP_CLOSE;
1198         sock->state = SS_UNCONNECTED;
1199
1200         if (addr_len != sizeof(*addr))
1201                 return -EINVAL;
1202
1203         addr = (struct sockaddr_at *)uaddr;
1204
1205         if (addr->sat_family != AF_APPLETALK)
1206                 return -EAFNOSUPPORT;
1207
1208         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1209             !sock_flag(sk, SOCK_BROADCAST)) {
1210 #if 1
1211                 printk(KERN_WARNING "%s is broken and did not set "
1212                                     "SO_BROADCAST. It will break when 2.2 is "
1213                                     "released.\n",
1214                         current->comm);
1215 #else
1216                 return -EACCES;
1217 #endif
1218         }
1219
1220         lock_sock(sk);
1221         err = -EBUSY;
1222         if (sock_flag(sk, SOCK_ZAPPED))
1223                 if (atalk_autobind(sk) < 0)
1224                         goto out;
1225
1226         err = -ENETUNREACH;
1227         if (!atrtr_get_dev(&addr->sat_addr))
1228                 goto out;
1229
1230         at->dest_port = addr->sat_port;
1231         at->dest_net  = addr->sat_addr.s_net;
1232         at->dest_node = addr->sat_addr.s_node;
1233
1234         sock->state  = SS_CONNECTED;
1235         sk->sk_state = TCP_ESTABLISHED;
1236         err = 0;
1237 out:
1238         release_sock(sk);
1239         return err;
1240 }
1241
1242 /*
1243  * Find the name of an AppleTalk socket. Just copy the right
1244  * fields into the sockaddr.
1245  */
1246 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1247                          int *uaddr_len, int peer)
1248 {
1249         struct sockaddr_at sat;
1250         struct sock *sk = sock->sk;
1251         struct atalk_sock *at = at_sk(sk);
1252         int err;
1253
1254         lock_sock(sk);
1255         err = -ENOBUFS;
1256         if (sock_flag(sk, SOCK_ZAPPED))
1257                 if (atalk_autobind(sk) < 0)
1258                         goto out;
1259
1260         *uaddr_len = sizeof(struct sockaddr_at);
1261         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
1262
1263         if (peer) {
1264                 err = -ENOTCONN;
1265                 if (sk->sk_state != TCP_ESTABLISHED)
1266                         goto out;
1267
1268                 sat.sat_addr.s_net  = at->dest_net;
1269                 sat.sat_addr.s_node = at->dest_node;
1270                 sat.sat_port        = at->dest_port;
1271         } else {
1272                 sat.sat_addr.s_net  = at->src_net;
1273                 sat.sat_addr.s_node = at->src_node;
1274                 sat.sat_port        = at->src_port;
1275         }
1276
1277         err = 0;
1278         sat.sat_family = AF_APPLETALK;
1279         memcpy(uaddr, &sat, sizeof(sat));
1280
1281 out:
1282         release_sock(sk);
1283         return err;
1284 }
1285
1286 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1287 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1288 {
1289         return skb->data[12] == 22;
1290 }
1291
1292 static int handle_ip_over_ddp(struct sk_buff *skb)
1293 {
1294         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1295         struct net_device_stats *stats;
1296
1297         /* This needs to be able to handle ipddp"N" devices */
1298         if (!dev) {
1299                 kfree_skb(skb);
1300                 return NET_RX_DROP;
1301         }
1302
1303         skb->protocol = htons(ETH_P_IP);
1304         skb_pull(skb, 13);
1305         skb->dev   = dev;
1306         skb_reset_transport_header(skb);
1307
1308         stats = netdev_priv(dev);
1309         stats->rx_packets++;
1310         stats->rx_bytes += skb->len + 13;
1311         return netif_rx(skb);  /* Send the SKB up to a higher place. */
1312 }
1313 #else
1314 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1315 #define is_ip_over_ddp(skb) 0
1316 #define handle_ip_over_ddp(skb) 0
1317 #endif
1318
1319 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1320                               struct ddpehdr *ddp, __u16 len_hops, int origlen)
1321 {
1322         struct atalk_route *rt;
1323         struct atalk_addr ta;
1324
1325         /*
1326          * Don't route multicast, etc., packets, or packets sent to "this
1327          * network"
1328          */
1329         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1330                 /*
1331                  * FIXME:
1332                  *
1333                  * Can it ever happen that a packet is from a PPP iface and
1334                  * needs to be broadcast onto the default network?
1335                  */
1336                 if (dev->type == ARPHRD_PPP)
1337                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1338                                           "packet received from PPP iface\n");
1339                 goto free_it;
1340         }
1341
1342         ta.s_net  = ddp->deh_dnet;
1343         ta.s_node = ddp->deh_dnode;
1344
1345         /* Route the packet */
1346         rt = atrtr_find(&ta);
1347         /* increment hops count */
1348         len_hops += 1 << 10;
1349         if (!rt || !(len_hops & (15 << 10)))
1350                 goto free_it;
1351
1352         /* FIXME: use skb->cb to be able to use shared skbs */
1353
1354         /*
1355          * Route goes through another gateway, so set the target to the
1356          * gateway instead.
1357          */
1358
1359         if (rt->flags & RTF_GATEWAY) {
1360                 ta.s_net  = rt->gateway.s_net;
1361                 ta.s_node = rt->gateway.s_node;
1362         }
1363
1364         /* Fix up skb->len field */
1365         skb_trim(skb, min_t(unsigned int, origlen,
1366                             (rt->dev->hard_header_len +
1367                              ddp_dl->header_length + (len_hops & 1023))));
1368
1369         /* FIXME: use skb->cb to be able to use shared skbs */
1370         ddp->deh_len_hops = htons(len_hops);
1371
1372         /*
1373          * Send the buffer onwards
1374          *
1375          * Now we must always be careful. If it's come from LocalTalk to
1376          * EtherTalk it might not fit
1377          *
1378          * Order matters here: If a packet has to be copied to make a new
1379          * headroom (rare hopefully) then it won't need unsharing.
1380          *
1381          * Note. ddp-> becomes invalid at the realloc.
1382          */
1383         if (skb_headroom(skb) < 22) {
1384                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1385                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1386                 kfree_skb(skb);
1387                 skb = nskb;
1388         } else
1389                 skb = skb_unshare(skb, GFP_ATOMIC);
1390
1391         /*
1392          * If the buffer didn't vanish into the lack of space bitbucket we can
1393          * send it.
1394          */
1395         if (skb == NULL)
1396                 goto drop;
1397
1398         if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1399                 return NET_RX_DROP;
1400         return NET_RX_SUCCESS;
1401 free_it:
1402         kfree_skb(skb);
1403 drop:
1404         return NET_RX_DROP;
1405 }
1406
1407 /**
1408  *      atalk_rcv - Receive a packet (in skb) from device dev
1409  *      @skb - packet received
1410  *      @dev - network device where the packet comes from
1411  *      @pt - packet type
1412  *
1413  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1414  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1415  *      is the DDP header, skb->len is the DDP length. The physical headers
1416  *      have been extracted. PPP should probably pass frames marked as for this
1417  *      layer.  [ie ARPHRD_ETHERTALK]
1418  */
1419 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1420                      struct packet_type *pt, struct net_device *orig_dev)
1421 {
1422         struct ddpehdr *ddp;
1423         struct sock *sock;
1424         struct atalk_iface *atif;
1425         struct sockaddr_at tosat;
1426         int origlen;
1427         __u16 len_hops;
1428
1429         if (!net_eq(dev_net(dev), &init_net))
1430                 goto drop;
1431
1432         /* Don't mangle buffer if shared */
1433         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1434                 goto out;
1435
1436         /* Size check and make sure header is contiguous */
1437         if (!pskb_may_pull(skb, sizeof(*ddp)))
1438                 goto drop;
1439
1440         ddp = ddp_hdr(skb);
1441
1442         len_hops = ntohs(ddp->deh_len_hops);
1443
1444         /* Trim buffer in case of stray trailing data */
1445         origlen = skb->len;
1446         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1447
1448         /*
1449          * Size check to see if ddp->deh_len was crap
1450          * (Otherwise we'll detonate most spectacularly
1451          * in the middle of atalk_checksum() or recvmsg()).
1452          */
1453         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1454                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1455                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1456                 goto drop;
1457         }
1458
1459         /*
1460          * Any checksums. Note we don't do htons() on this == is assumed to be
1461          * valid for net byte orders all over the networking code...
1462          */
1463         if (ddp->deh_sum &&
1464             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1465                 /* Not a valid AppleTalk frame - dustbin time */
1466                 goto drop;
1467
1468         /* Check the packet is aimed at us */
1469         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1470                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1471         else
1472                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1473
1474         if (!atif) {
1475                 /* Not ours, so we route the packet via the correct
1476                  * AppleTalk iface
1477                  */
1478                 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1479         }
1480
1481         /* if IP over DDP is not selected this code will be optimized out */
1482         if (is_ip_over_ddp(skb))
1483                 return handle_ip_over_ddp(skb);
1484         /*
1485          * Which socket - atalk_search_socket() looks for a *full match*
1486          * of the <net, node, port> tuple.
1487          */
1488         tosat.sat_addr.s_net  = ddp->deh_dnet;
1489         tosat.sat_addr.s_node = ddp->deh_dnode;
1490         tosat.sat_port        = ddp->deh_dport;
1491
1492         sock = atalk_search_socket(&tosat, atif);
1493         if (!sock) /* But not one of our sockets */
1494                 goto drop;
1495
1496         /* Queue packet (standard) */
1497         skb->sk = sock;
1498
1499         if (sock_queue_rcv_skb(sock, skb) < 0)
1500                 goto drop;
1501
1502         return NET_RX_SUCCESS;
1503
1504 drop:
1505         kfree_skb(skb);
1506 out:
1507         return NET_RX_DROP;
1508
1509 }
1510
1511 /*
1512  * Receive a LocalTalk frame. We make some demands on the caller here.
1513  * Caller must provide enough headroom on the packet to pull the short
1514  * header and append a long one.
1515  */
1516 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1517                      struct packet_type *pt, struct net_device *orig_dev)
1518 {
1519         if (!net_eq(dev_net(dev), &init_net))
1520                 goto freeit;
1521
1522         /* Expand any short form frames */
1523         if (skb_mac_header(skb)[2] == 1) {
1524                 struct ddpehdr *ddp;
1525                 /* Find our address */
1526                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1527
1528                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1529                         goto freeit;
1530
1531                 /* Don't mangle buffer if shared */
1532                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1533                         return 0;
1534
1535                 /*
1536                  * The push leaves us with a ddephdr not an shdr, and
1537                  * handily the port bytes in the right place preset.
1538                  */
1539                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1540
1541                 /* Now fill in the long header */
1542
1543                 /*
1544                  * These two first. The mac overlays the new source/dest
1545                  * network information so we MUST copy these before
1546                  * we write the network numbers !
1547                  */
1548
1549                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1550                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1551
1552                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1553                 ddp->deh_snet  = ap->s_net;
1554                 ddp->deh_sum   = 0;             /* No checksum */
1555                 /*
1556                  * Not sure about this bit...
1557                  */
1558                 /* Non routable, so force a drop if we slip up later */
1559                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1560         }
1561         skb_reset_transport_header(skb);
1562
1563         return atalk_rcv(skb, dev, pt, orig_dev);
1564 freeit:
1565         kfree_skb(skb);
1566         return 0;
1567 }
1568
1569 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1570                          size_t len)
1571 {
1572         struct sock *sk = sock->sk;
1573         struct atalk_sock *at = at_sk(sk);
1574         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1575         int flags = msg->msg_flags;
1576         int loopback = 0;
1577         struct sockaddr_at local_satalk, gsat;
1578         struct sk_buff *skb;
1579         struct net_device *dev;
1580         struct ddpehdr *ddp;
1581         int size;
1582         struct atalk_route *rt;
1583         int err;
1584
1585         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1586                 return -EINVAL;
1587
1588         if (len > DDP_MAXSZ)
1589                 return -EMSGSIZE;
1590
1591         lock_sock(sk);
1592         if (usat) {
1593                 err = -EBUSY;
1594                 if (sock_flag(sk, SOCK_ZAPPED))
1595                         if (atalk_autobind(sk) < 0)
1596                                 goto out;
1597
1598                 err = -EINVAL;
1599                 if (msg->msg_namelen < sizeof(*usat) ||
1600                     usat->sat_family != AF_APPLETALK)
1601                         goto out;
1602
1603                 err = -EPERM;
1604                 /* netatalk didn't implement this check */
1605                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1606                     !sock_flag(sk, SOCK_BROADCAST)) {
1607                         goto out;
1608                 }
1609         } else {
1610                 err = -ENOTCONN;
1611                 if (sk->sk_state != TCP_ESTABLISHED)
1612                         goto out;
1613                 usat = &local_satalk;
1614                 usat->sat_family      = AF_APPLETALK;
1615                 usat->sat_port        = at->dest_port;
1616                 usat->sat_addr.s_node = at->dest_node;
1617                 usat->sat_addr.s_net  = at->dest_net;
1618         }
1619
1620         /* Build a packet */
1621         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1622
1623         /* For headers */
1624         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1625
1626         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1627                 rt = atrtr_find(&usat->sat_addr);
1628         } else {
1629                 struct atalk_addr at_hint;
1630
1631                 at_hint.s_node = 0;
1632                 at_hint.s_net  = at->src_net;
1633
1634                 rt = atrtr_find(&at_hint);
1635         }
1636         err = ENETUNREACH;
1637         if (!rt)
1638                 goto out;
1639
1640         dev = rt->dev;
1641
1642         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1643                         sk, size, dev->name);
1644
1645         size += dev->hard_header_len;
1646         release_sock(sk);
1647         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1648         lock_sock(sk);
1649         if (!skb)
1650                 goto out;
1651
1652         skb->sk = sk;
1653         skb_reserve(skb, ddp_dl->header_length);
1654         skb_reserve(skb, dev->hard_header_len);
1655         skb->dev = dev;
1656
1657         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1658
1659         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1660         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1661         ddp->deh_dnet  = usat->sat_addr.s_net;
1662         ddp->deh_snet  = at->src_net;
1663         ddp->deh_dnode = usat->sat_addr.s_node;
1664         ddp->deh_snode = at->src_node;
1665         ddp->deh_dport = usat->sat_port;
1666         ddp->deh_sport = at->src_port;
1667
1668         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1669
1670         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1671         if (err) {
1672                 kfree_skb(skb);
1673                 err = -EFAULT;
1674                 goto out;
1675         }
1676
1677         if (sk->sk_no_check == 1)
1678                 ddp->deh_sum = 0;
1679         else
1680                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1681
1682         /*
1683          * Loopback broadcast packets to non gateway targets (ie routes
1684          * to group we are in)
1685          */
1686         if (ddp->deh_dnode == ATADDR_BCAST &&
1687             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1688                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1689
1690                 if (skb2) {
1691                         loopback = 1;
1692                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1693                         /*
1694                          * If it fails it is queued/sent above in the aarp queue
1695                          */
1696                         aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1697                 }
1698         }
1699
1700         if (dev->flags & IFF_LOOPBACK || loopback) {
1701                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1702                 /* loop back */
1703                 skb_orphan(skb);
1704                 if (ddp->deh_dnode == ATADDR_BCAST) {
1705                         struct atalk_addr at_lo;
1706
1707                         at_lo.s_node = 0;
1708                         at_lo.s_net  = 0;
1709
1710                         rt = atrtr_find(&at_lo);
1711                         if (!rt) {
1712                                 kfree_skb(skb);
1713                                 err = -ENETUNREACH;
1714                                 goto out;
1715                         }
1716                         dev = rt->dev;
1717                         skb->dev = dev;
1718                 }
1719                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1720         } else {
1721                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1722                 if (rt->flags & RTF_GATEWAY) {
1723                     gsat.sat_addr = rt->gateway;
1724                     usat = &gsat;
1725                 }
1726
1727                 /*
1728                  * If it fails it is queued/sent above in the aarp queue
1729                  */
1730                 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1731         }
1732         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1733
1734 out:
1735         release_sock(sk);
1736         return err ? : len;
1737 }
1738
1739 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1740                          size_t size, int flags)
1741 {
1742         struct sock *sk = sock->sk;
1743         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1744         struct ddpehdr *ddp;
1745         int copied = 0;
1746         int offset = 0;
1747         int err = 0;
1748         struct sk_buff *skb;
1749
1750         skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1751                                                 flags & MSG_DONTWAIT, &err);
1752         lock_sock(sk);
1753
1754         if (!skb)
1755                 goto out;
1756
1757         /* FIXME: use skb->cb to be able to use shared skbs */
1758         ddp = ddp_hdr(skb);
1759         copied = ntohs(ddp->deh_len_hops) & 1023;
1760
1761         if (sk->sk_type != SOCK_RAW) {
1762                 offset = sizeof(*ddp);
1763                 copied -= offset;
1764         }
1765
1766         if (copied > size) {
1767                 copied = size;
1768                 msg->msg_flags |= MSG_TRUNC;
1769         }
1770         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1771
1772         if (!err) {
1773                 if (sat) {
1774                         sat->sat_family      = AF_APPLETALK;
1775                         sat->sat_port        = ddp->deh_sport;
1776                         sat->sat_addr.s_node = ddp->deh_snode;
1777                         sat->sat_addr.s_net  = ddp->deh_snet;
1778                 }
1779                 msg->msg_namelen = sizeof(*sat);
1780         }
1781
1782         skb_free_datagram(sk, skb);     /* Free the datagram. */
1783
1784 out:
1785         release_sock(sk);
1786         return err ? : copied;
1787 }
1788
1789
1790 /*
1791  * AppleTalk ioctl calls.
1792  */
1793 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1794 {
1795         int rc = -ENOIOCTLCMD;
1796         struct sock *sk = sock->sk;
1797         void __user *argp = (void __user *)arg;
1798
1799         switch (cmd) {
1800                 /* Protocol layer */
1801                 case TIOCOUTQ: {
1802                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1803
1804                         if (amount < 0)
1805                                 amount = 0;
1806                         rc = put_user(amount, (int __user *)argp);
1807                         break;
1808                 }
1809                 case TIOCINQ: {
1810                         /*
1811                          * These two are safe on a single CPU system as only
1812                          * user tasks fiddle here
1813                          */
1814                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1815                         long amount = 0;
1816
1817                         if (skb)
1818                                 amount = skb->len - sizeof(struct ddpehdr);
1819                         rc = put_user(amount, (int __user *)argp);
1820                         break;
1821                 }
1822                 case SIOCGSTAMP:
1823                         rc = sock_get_timestamp(sk, argp);
1824                         break;
1825                 case SIOCGSTAMPNS:
1826                         rc = sock_get_timestampns(sk, argp);
1827                         break;
1828                 /* Routing */
1829                 case SIOCADDRT:
1830                 case SIOCDELRT:
1831                         rc = -EPERM;
1832                         if (capable(CAP_NET_ADMIN))
1833                                 rc = atrtr_ioctl(cmd, argp);
1834                         break;
1835                 /* Interface */
1836                 case SIOCGIFADDR:
1837                 case SIOCSIFADDR:
1838                 case SIOCGIFBRDADDR:
1839                 case SIOCATALKDIFADDR:
1840                 case SIOCDIFADDR:
1841                 case SIOCSARP:          /* proxy AARP */
1842                 case SIOCDARP:          /* proxy AARP */
1843                         rtnl_lock();
1844                         rc = atif_ioctl(cmd, argp);
1845                         rtnl_unlock();
1846                         break;
1847         }
1848
1849         return rc;
1850 }
1851
1852
1853 #ifdef CONFIG_COMPAT
1854 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1855 {
1856         /*
1857          * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1858          * cannot handle it in common code. The data we access if ifreq
1859          * here is compatible, so we can simply call the native
1860          * handler.
1861          */
1862         if (cmd == SIOCATALKDIFADDR)
1863                 return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1864
1865         return -ENOIOCTLCMD;
1866 }
1867 #endif
1868
1869
1870 static const struct net_proto_family atalk_family_ops = {
1871         .family         = PF_APPLETALK,
1872         .create         = atalk_create,
1873         .owner          = THIS_MODULE,
1874 };
1875
1876 static const struct proto_ops atalk_dgram_ops = {
1877         .family         = PF_APPLETALK,
1878         .owner          = THIS_MODULE,
1879         .release        = atalk_release,
1880         .bind           = atalk_bind,
1881         .connect        = atalk_connect,
1882         .socketpair     = sock_no_socketpair,
1883         .accept         = sock_no_accept,
1884         .getname        = atalk_getname,
1885         .poll           = datagram_poll,
1886         .ioctl          = atalk_ioctl,
1887 #ifdef CONFIG_COMPAT
1888         .compat_ioctl   = atalk_compat_ioctl,
1889 #endif
1890         .listen         = sock_no_listen,
1891         .shutdown       = sock_no_shutdown,
1892         .setsockopt     = sock_no_setsockopt,
1893         .getsockopt     = sock_no_getsockopt,
1894         .sendmsg        = atalk_sendmsg,
1895         .recvmsg        = atalk_recvmsg,
1896         .mmap           = sock_no_mmap,
1897         .sendpage       = sock_no_sendpage,
1898 };
1899
1900 static struct notifier_block ddp_notifier = {
1901         .notifier_call  = ddp_device_event,
1902 };
1903
1904 static struct packet_type ltalk_packet_type __read_mostly = {
1905         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1906         .func           = ltalk_rcv,
1907 };
1908
1909 static struct packet_type ppptalk_packet_type __read_mostly = {
1910         .type           = cpu_to_be16(ETH_P_PPPTALK),
1911         .func           = atalk_rcv,
1912 };
1913
1914 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1915
1916 /* Export symbols for use by drivers when AppleTalk is a module */
1917 EXPORT_SYMBOL(atrtr_get_dev);
1918 EXPORT_SYMBOL(atalk_find_dev_addr);
1919
1920 static const char atalk_err_snap[] __initconst =
1921         KERN_CRIT "Unable to register DDP with SNAP.\n";
1922
1923 /* Called by proto.c on kernel start up */
1924 static int __init atalk_init(void)
1925 {
1926         int rc = proto_register(&ddp_proto, 0);
1927
1928         if (rc != 0)
1929                 goto out;
1930
1931         (void)sock_register(&atalk_family_ops);
1932         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1933         if (!ddp_dl)
1934                 printk(atalk_err_snap);
1935
1936         dev_add_pack(&ltalk_packet_type);
1937         dev_add_pack(&ppptalk_packet_type);
1938
1939         register_netdevice_notifier(&ddp_notifier);
1940         aarp_proto_init();
1941         atalk_proc_init();
1942         atalk_register_sysctl();
1943 out:
1944         return rc;
1945 }
1946 module_init(atalk_init);
1947
1948 /*
1949  * No explicit module reference count manipulation is needed in the
1950  * protocol. Socket layer sets module reference count for us
1951  * and interfaces reference counting is done
1952  * by the network device layer.
1953  *
1954  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1955  * sockets be closed from user space.
1956  */
1957 static void __exit atalk_exit(void)
1958 {
1959 #ifdef CONFIG_SYSCTL
1960         atalk_unregister_sysctl();
1961 #endif /* CONFIG_SYSCTL */
1962         atalk_proc_exit();
1963         aarp_cleanup_module();  /* General aarp clean-up. */
1964         unregister_netdevice_notifier(&ddp_notifier);
1965         dev_remove_pack(&ltalk_packet_type);
1966         dev_remove_pack(&ppptalk_packet_type);
1967         unregister_snap_client(ddp_dl);
1968         sock_unregister(PF_APPLETALK);
1969         proto_unregister(&ddp_proto);
1970 }
1971 module_exit(atalk_exit);
1972
1973 MODULE_LICENSE("GPL");
1974 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1975 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1976 MODULE_ALIAS_NETPROTO(PF_APPLETALK);