net: mark net_proto_ops as const
[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/smp_lock.h>
58 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
59 #include <net/datalink.h>
60 #include <net/psnap.h>
61 #include <net/sock.h>
62 #include <net/tcp_states.h>
63 #include <net/route.h>
64 #include <linux/atalk.h>
65 #include "../core/kmap_skb.h"
66
67 struct datalink_proto *ddp_dl, *aarp_dl;
68 static const struct proto_ops atalk_dgram_ops;
69
70 /**************************************************************************\
71 *                                                                          *
72 * Handlers for the socket list.                                            *
73 *                                                                          *
74 \**************************************************************************/
75
76 HLIST_HEAD(atalk_sockets);
77 DEFINE_RWLOCK(atalk_sockets_lock);
78
79 static inline void __atalk_insert_socket(struct sock *sk)
80 {
81         sk_add_node(sk, &atalk_sockets);
82 }
83
84 static inline void atalk_remove_socket(struct sock *sk)
85 {
86         write_lock_bh(&atalk_sockets_lock);
87         sk_del_node_init(sk);
88         write_unlock_bh(&atalk_sockets_lock);
89 }
90
91 static struct sock *atalk_search_socket(struct sockaddr_at *to,
92                                         struct atalk_iface *atif)
93 {
94         struct sock *s;
95         struct hlist_node *node;
96
97         read_lock_bh(&atalk_sockets_lock);
98         sk_for_each(s, node, &atalk_sockets) {
99                 struct atalk_sock *at = at_sk(s);
100
101                 if (to->sat_port != at->src_port)
102                         continue;
103
104                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
105                     to->sat_addr.s_node == ATADDR_BCAST)
106                         goto found;
107
108                 if (to->sat_addr.s_net == at->src_net &&
109                     (to->sat_addr.s_node == at->src_node ||
110                      to->sat_addr.s_node == ATADDR_BCAST ||
111                      to->sat_addr.s_node == ATADDR_ANYNODE))
112                         goto found;
113
114                 /* XXXX.0 -- we got a request for this router. make sure
115                  * that the node is appropriately set. */
116                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
117                     to->sat_addr.s_net != ATADDR_ANYNET &&
118                     atif->address.s_node == at->src_node) {
119                         to->sat_addr.s_node = atif->address.s_node;
120                         goto found;
121                 }
122         }
123         s = NULL;
124 found:
125         read_unlock_bh(&atalk_sockets_lock);
126         return s;
127 }
128
129 /**
130  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
131  * @sk - socket to insert in the list if it is not there already
132  * @sat - address to search for
133  *
134  * Try to find a socket matching ADDR in the socket list, if found then return
135  * it. If not, insert SK into the socket list.
136  *
137  * This entire operation must execute atomically.
138  */
139 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
140                                                 struct sockaddr_at *sat)
141 {
142         struct sock *s;
143         struct hlist_node *node;
144         struct atalk_sock *at;
145
146         write_lock_bh(&atalk_sockets_lock);
147         sk_for_each(s, node, &atalk_sockets) {
148                 at = at_sk(s);
149
150                 if (at->src_net == sat->sat_addr.s_net &&
151                     at->src_node == sat->sat_addr.s_node &&
152                     at->src_port == sat->sat_port)
153                         goto found;
154         }
155         s = NULL;
156         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
157 found:
158         write_unlock_bh(&atalk_sockets_lock);
159         return s;
160 }
161
162 static void atalk_destroy_timer(unsigned long data)
163 {
164         struct sock *sk = (struct sock *)data;
165
166         if (sk_has_allocations(sk)) {
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 (sk_has_allocations(sk)) {
179                 setup_timer(&sk->sk_timer, atalk_destroy_timer,
180                                 (unsigned long)sk);
181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
182                 add_timer(&sk->sk_timer);
183         } else
184                 sock_put(sk);
185 }
186
187 /**************************************************************************\
188 *                                                                          *
189 * Routing tables for the AppleTalk socket layer.                           *
190 *                                                                          *
191 \**************************************************************************/
192
193 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
194 struct atalk_route *atalk_routes;
195 DEFINE_RWLOCK(atalk_routes_lock);
196
197 struct atalk_iface *atalk_interfaces;
198 DEFINE_RWLOCK(atalk_interfaces_lock);
199
200 /* For probing devices or in a routerless network */
201 struct atalk_route atrtr_default;
202
203 /* AppleTalk interface control */
204 /*
205  * Drop a device. Doesn't drop any of its routes - that is the caller's
206  * problem. Called when we down the interface or delete the address.
207  */
208 static void atif_drop_device(struct net_device *dev)
209 {
210         struct atalk_iface **iface = &atalk_interfaces;
211         struct atalk_iface *tmp;
212
213         write_lock_bh(&atalk_interfaces_lock);
214         while ((tmp = *iface) != NULL) {
215                 if (tmp->dev == dev) {
216                         *iface = tmp->next;
217                         dev_put(dev);
218                         kfree(tmp);
219                         dev->atalk_ptr = NULL;
220                 } else
221                         iface = &tmp->next;
222         }
223         write_unlock_bh(&atalk_interfaces_lock);
224 }
225
226 static struct atalk_iface *atif_add_device(struct net_device *dev,
227                                            struct atalk_addr *sa)
228 {
229         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
230
231         if (!iface)
232                 goto out;
233
234         dev_hold(dev);
235         iface->dev = dev;
236         dev->atalk_ptr = iface;
237         iface->address = *sa;
238         iface->status = 0;
239
240         write_lock_bh(&atalk_interfaces_lock);
241         iface->next = atalk_interfaces;
242         atalk_interfaces = iface;
243         write_unlock_bh(&atalk_interfaces_lock);
244 out:
245         return iface;
246 }
247
248 /* Perform phase 2 AARP probing on our tentative address */
249 static int atif_probe_device(struct atalk_iface *atif)
250 {
251         int netrange = ntohs(atif->nets.nr_lastnet) -
252                         ntohs(atif->nets.nr_firstnet) + 1;
253         int probe_net = ntohs(atif->address.s_net);
254         int probe_node = atif->address.s_node;
255         int netct, nodect;
256
257         /* Offset the network we start probing with */
258         if (probe_net == ATADDR_ANYNET) {
259                 probe_net = ntohs(atif->nets.nr_firstnet);
260                 if (netrange)
261                         probe_net += jiffies % netrange;
262         }
263         if (probe_node == ATADDR_ANYNODE)
264                 probe_node = jiffies & 0xFF;
265
266         /* Scan the networks */
267         atif->status |= ATIF_PROBE;
268         for (netct = 0; netct <= netrange; netct++) {
269                 /* Sweep the available nodes from a given start */
270                 atif->address.s_net = htons(probe_net);
271                 for (nodect = 0; nodect < 256; nodect++) {
272                         atif->address.s_node = (nodect + probe_node) & 0xFF;
273                         if (atif->address.s_node > 0 &&
274                             atif->address.s_node < 254) {
275                                 /* Probe a proposed address */
276                                 aarp_probe_network(atif);
277
278                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
279                                         atif->status &= ~ATIF_PROBE;
280                                         return 0;
281                                 }
282                         }
283                         atif->status &= ~ATIF_PROBE_FAIL;
284                 }
285                 probe_net++;
286                 if (probe_net > ntohs(atif->nets.nr_lastnet))
287                         probe_net = ntohs(atif->nets.nr_firstnet);
288         }
289         atif->status &= ~ATIF_PROBE;
290
291         return -EADDRINUSE;     /* Network is full... */
292 }
293
294
295 /* Perform AARP probing for a proxy address */
296 static int atif_proxy_probe_device(struct atalk_iface *atif,
297                                    struct atalk_addr* proxy_addr)
298 {
299         int netrange = ntohs(atif->nets.nr_lastnet) -
300                         ntohs(atif->nets.nr_firstnet) + 1;
301         /* we probe the interface's network */
302         int probe_net = ntohs(atif->address.s_net);
303         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
304         int netct, nodect;
305
306         /* Offset the network we start probing with */
307         if (probe_net == ATADDR_ANYNET) {
308                 probe_net = ntohs(atif->nets.nr_firstnet);
309                 if (netrange)
310                         probe_net += jiffies % netrange;
311         }
312
313         if (probe_node == ATADDR_ANYNODE)
314                 probe_node = jiffies & 0xFF;
315
316         /* Scan the networks */
317         for (netct = 0; netct <= netrange; netct++) {
318                 /* Sweep the available nodes from a given start */
319                 proxy_addr->s_net = htons(probe_net);
320                 for (nodect = 0; nodect < 256; nodect++) {
321                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
322                         if (proxy_addr->s_node > 0 &&
323                             proxy_addr->s_node < 254) {
324                                 /* Tell AARP to probe a proposed address */
325                                 int ret = aarp_proxy_probe_network(atif,
326                                                                     proxy_addr);
327
328                                 if (ret != -EADDRINUSE)
329                                         return ret;
330                         }
331                 }
332                 probe_net++;
333                 if (probe_net > ntohs(atif->nets.nr_lastnet))
334                         probe_net = ntohs(atif->nets.nr_firstnet);
335         }
336
337         return -EADDRINUSE;     /* Network is full... */
338 }
339
340
341 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
342 {
343         struct atalk_iface *iface = dev->atalk_ptr;
344         return iface ? &iface->address : NULL;
345 }
346
347 static struct atalk_addr *atalk_find_primary(void)
348 {
349         struct atalk_iface *fiface = NULL;
350         struct atalk_addr *retval;
351         struct atalk_iface *iface;
352
353         /*
354          * Return a point-to-point interface only if
355          * there is no non-ptp interface available.
356          */
357         read_lock_bh(&atalk_interfaces_lock);
358         for (iface = atalk_interfaces; iface; iface = iface->next) {
359                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
360                         fiface = iface;
361                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
362                         retval = &iface->address;
363                         goto out;
364                 }
365         }
366
367         if (fiface)
368                 retval = &fiface->address;
369         else if (atalk_interfaces)
370                 retval = &atalk_interfaces->address;
371         else
372                 retval = NULL;
373 out:
374         read_unlock_bh(&atalk_interfaces_lock);
375         return retval;
376 }
377
378 /*
379  * Find a match for 'any network' - ie any of our interfaces with that
380  * node number will do just nicely.
381  */
382 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
383 {
384         struct atalk_iface *iface = dev->atalk_ptr;
385
386         if (!iface || iface->status & ATIF_PROBE)
387                 goto out_err;
388
389         if (node != ATADDR_BCAST &&
390             iface->address.s_node != node &&
391             node != ATADDR_ANYNODE)
392                 goto out_err;
393 out:
394         return iface;
395 out_err:
396         iface = NULL;
397         goto out;
398 }
399
400 /* Find a match for a specific network:node pair */
401 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
402 {
403         struct atalk_iface *iface;
404
405         read_lock_bh(&atalk_interfaces_lock);
406         for (iface = atalk_interfaces; iface; iface = iface->next) {
407                 if ((node == ATADDR_BCAST ||
408                      node == ATADDR_ANYNODE ||
409                      iface->address.s_node == node) &&
410                     iface->address.s_net == net &&
411                     !(iface->status & ATIF_PROBE))
412                         break;
413
414                 /* XXXX.0 -- net.0 returns the iface associated with net */
415                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
416                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
417                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
418                         break;
419         }
420         read_unlock_bh(&atalk_interfaces_lock);
421         return iface;
422 }
423
424
425 /*
426  * Find a route for an AppleTalk packet. This ought to get cached in
427  * the socket (later on...). We know about host routes and the fact
428  * that a route must be direct to broadcast.
429  */
430 static struct atalk_route *atrtr_find(struct atalk_addr *target)
431 {
432         /*
433          * we must search through all routes unless we find a
434          * host route, because some host routes might overlap
435          * network routes
436          */
437         struct atalk_route *net_route = NULL;
438         struct atalk_route *r;
439
440         read_lock_bh(&atalk_routes_lock);
441         for (r = atalk_routes; r; r = r->next) {
442                 if (!(r->flags & RTF_UP))
443                         continue;
444
445                 if (r->target.s_net == target->s_net) {
446                         if (r->flags & RTF_HOST) {
447                                 /*
448                                  * if this host route is for the target,
449                                  * the we're done
450                                  */
451                                 if (r->target.s_node == target->s_node)
452                                         goto out;
453                         } else
454                                 /*
455                                  * this route will work if there isn't a
456                                  * direct host route, so cache it
457                                  */
458                                 net_route = r;
459                 }
460         }
461
462         /*
463          * if we found a network route but not a direct host
464          * route, then return it
465          */
466         if (net_route)
467                 r = net_route;
468         else if (atrtr_default.dev)
469                 r = &atrtr_default;
470         else /* No route can be found */
471                 r = NULL;
472 out:
473         read_unlock_bh(&atalk_routes_lock);
474         return r;
475 }
476
477
478 /*
479  * Given an AppleTalk network, find the device to use. This can be
480  * a simple lookup.
481  */
482 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
483 {
484         struct atalk_route *atr = atrtr_find(sa);
485         return atr ? atr->dev : NULL;
486 }
487
488 /* Set up a default router */
489 static void atrtr_set_default(struct net_device *dev)
490 {
491         atrtr_default.dev            = dev;
492         atrtr_default.flags          = RTF_UP;
493         atrtr_default.gateway.s_net  = htons(0);
494         atrtr_default.gateway.s_node = 0;
495 }
496
497 /*
498  * Add a router. Basically make sure it looks valid and stuff the
499  * entry in the list. While it uses netranges we always set them to one
500  * entry to work like netatalk.
501  */
502 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
503 {
504         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
505         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
506         struct atalk_route *rt;
507         struct atalk_iface *iface, *riface;
508         int retval = -EINVAL;
509
510         /*
511          * Fixme: Raise/Lower a routing change semaphore for these
512          * operations.
513          */
514
515         /* Validate the request */
516         if (ta->sat_family != AF_APPLETALK ||
517             (!devhint && ga->sat_family != AF_APPLETALK))
518                 goto out;
519
520         /* Now walk the routing table and make our decisions */
521         write_lock_bh(&atalk_routes_lock);
522         for (rt = atalk_routes; rt; rt = rt->next) {
523                 if (r->rt_flags != rt->flags)
524                         continue;
525
526                 if (ta->sat_addr.s_net == rt->target.s_net) {
527                         if (!(rt->flags & RTF_HOST))
528                                 break;
529                         if (ta->sat_addr.s_node == rt->target.s_node)
530                                 break;
531                 }
532         }
533
534         if (!devhint) {
535                 riface = NULL;
536
537                 read_lock_bh(&atalk_interfaces_lock);
538                 for (iface = atalk_interfaces; iface; iface = iface->next) {
539                         if (!riface &&
540                             ntohs(ga->sat_addr.s_net) >=
541                                         ntohs(iface->nets.nr_firstnet) &&
542                             ntohs(ga->sat_addr.s_net) <=
543                                         ntohs(iface->nets.nr_lastnet))
544                                 riface = iface;
545
546                         if (ga->sat_addr.s_net == iface->address.s_net &&
547                             ga->sat_addr.s_node == iface->address.s_node)
548                                 riface = iface;
549                 }
550                 read_unlock_bh(&atalk_interfaces_lock);
551
552                 retval = -ENETUNREACH;
553                 if (!riface)
554                         goto out_unlock;
555
556                 devhint = riface->dev;
557         }
558
559         if (!rt) {
560                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
561
562                 retval = -ENOBUFS;
563                 if (!rt)
564                         goto out_unlock;
565
566                 rt->next = atalk_routes;
567                 atalk_routes = rt;
568         }
569
570         /* Fill in the routing entry */
571         rt->target  = ta->sat_addr;
572         dev_hold(devhint);
573         rt->dev     = devhint;
574         rt->flags   = r->rt_flags;
575         rt->gateway = ga->sat_addr;
576
577         retval = 0;
578 out_unlock:
579         write_unlock_bh(&atalk_routes_lock);
580 out:
581         return retval;
582 }
583
584 /* Delete a route. Find it and discard it */
585 static int atrtr_delete(struct atalk_addr * addr)
586 {
587         struct atalk_route **r = &atalk_routes;
588         int retval = 0;
589         struct atalk_route *tmp;
590
591         write_lock_bh(&atalk_routes_lock);
592         while ((tmp = *r) != NULL) {
593                 if (tmp->target.s_net == addr->s_net &&
594                     (!(tmp->flags&RTF_GATEWAY) ||
595                      tmp->target.s_node == addr->s_node)) {
596                         *r = tmp->next;
597                         dev_put(tmp->dev);
598                         kfree(tmp);
599                         goto out;
600                 }
601                 r = &tmp->next;
602         }
603         retval = -ENOENT;
604 out:
605         write_unlock_bh(&atalk_routes_lock);
606         return retval;
607 }
608
609 /*
610  * Called when a device is downed. Just throw away any routes
611  * via it.
612  */
613 static void atrtr_device_down(struct net_device *dev)
614 {
615         struct atalk_route **r = &atalk_routes;
616         struct atalk_route *tmp;
617
618         write_lock_bh(&atalk_routes_lock);
619         while ((tmp = *r) != NULL) {
620                 if (tmp->dev == dev) {
621                         *r = tmp->next;
622                         dev_put(dev);
623                         kfree(tmp);
624                 } else
625                         r = &tmp->next;
626         }
627         write_unlock_bh(&atalk_routes_lock);
628
629         if (atrtr_default.dev == dev)
630                 atrtr_set_default(NULL);
631 }
632
633 /* Actually down the interface */
634 static inline void atalk_dev_down(struct net_device *dev)
635 {
636         atrtr_device_down(dev); /* Remove all routes for the device */
637         aarp_device_down(dev);  /* Remove AARP entries for the device */
638         atif_drop_device(dev);  /* Remove the device */
639 }
640
641 /*
642  * A device event has occurred. Watch for devices going down and
643  * delete our use of them (iface and route).
644  */
645 static int ddp_device_event(struct notifier_block *this, unsigned long event,
646                             void *ptr)
647 {
648         struct net_device *dev = ptr;
649
650         if (!net_eq(dev_net(dev), &init_net))
651                 return NOTIFY_DONE;
652
653         if (event == NETDEV_DOWN)
654                 /* Discard any use of this */
655                 atalk_dev_down(dev);
656
657         return NOTIFY_DONE;
658 }
659
660 /* ioctl calls. Shouldn't even need touching */
661 /* Device configuration ioctl calls */
662 static int atif_ioctl(int cmd, void __user *arg)
663 {
664         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
665         struct ifreq atreq;
666         struct atalk_netrange *nr;
667         struct sockaddr_at *sa;
668         struct net_device *dev;
669         struct atalk_iface *atif;
670         int ct;
671         int limit;
672         struct rtentry rtdef;
673         int add_route;
674
675         if (copy_from_user(&atreq, arg, sizeof(atreq)))
676                 return -EFAULT;
677
678         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
679         if (!dev)
680                 return -ENODEV;
681
682         sa = (struct sockaddr_at *)&atreq.ifr_addr;
683         atif = atalk_find_dev(dev);
684
685         switch (cmd) {
686                 case SIOCSIFADDR:
687                         if (!capable(CAP_NET_ADMIN))
688                                 return -EPERM;
689                         if (sa->sat_family != AF_APPLETALK)
690                                 return -EINVAL;
691                         if (dev->type != ARPHRD_ETHER &&
692                             dev->type != ARPHRD_LOOPBACK &&
693                             dev->type != ARPHRD_LOCALTLK &&
694                             dev->type != ARPHRD_PPP)
695                                 return -EPROTONOSUPPORT;
696
697                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
698                         add_route = 1;
699
700                         /*
701                          * if this is a point-to-point iface, and we already
702                          * have an iface for this AppleTalk address, then we
703                          * should not add a route
704                          */
705                         if ((dev->flags & IFF_POINTOPOINT) &&
706                             atalk_find_interface(sa->sat_addr.s_net,
707                                                  sa->sat_addr.s_node)) {
708                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
709                                                   "interface added with "
710                                                   "existing address\n");
711                                 add_route = 0;
712                         }
713
714                         /*
715                          * Phase 1 is fine on LocalTalk but we don't do
716                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
717                          */
718                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
719                                 return -EPROTONOSUPPORT;
720                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
721                             sa->sat_addr.s_node == 254)
722                                 return -EINVAL;
723                         if (atif) {
724                                 /* Already setting address */
725                                 if (atif->status & ATIF_PROBE)
726                                         return -EBUSY;
727
728                                 atif->address.s_net  = sa->sat_addr.s_net;
729                                 atif->address.s_node = sa->sat_addr.s_node;
730                                 atrtr_device_down(dev); /* Flush old routes */
731                         } else {
732                                 atif = atif_add_device(dev, &sa->sat_addr);
733                                 if (!atif)
734                                         return -ENOMEM;
735                         }
736                         atif->nets = *nr;
737
738                         /*
739                          * Check if the chosen address is used. If so we
740                          * error and atalkd will try another.
741                          */
742
743                         if (!(dev->flags & IFF_LOOPBACK) &&
744                             !(dev->flags & IFF_POINTOPOINT) &&
745                             atif_probe_device(atif) < 0) {
746                                 atif_drop_device(dev);
747                                 return -EADDRINUSE;
748                         }
749
750                         /* Hey it worked - add the direct routes */
751                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
752                         sa->sat_family = AF_APPLETALK;
753                         sa->sat_addr.s_net  = atif->address.s_net;
754                         sa->sat_addr.s_node = atif->address.s_node;
755                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
756                         rtdef.rt_flags = RTF_UP;
757                         sa->sat_family = AF_APPLETALK;
758                         sa->sat_addr.s_node = ATADDR_ANYNODE;
759                         if (dev->flags & IFF_LOOPBACK ||
760                             dev->flags & IFF_POINTOPOINT)
761                                 rtdef.rt_flags |= RTF_HOST;
762
763                         /* Routerless initial state */
764                         if (nr->nr_firstnet == htons(0) &&
765                             nr->nr_lastnet == htons(0xFFFE)) {
766                                 sa->sat_addr.s_net = atif->address.s_net;
767                                 atrtr_create(&rtdef, dev);
768                                 atrtr_set_default(dev);
769                         } else {
770                                 limit = ntohs(nr->nr_lastnet);
771                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
772                                         printk(KERN_WARNING "Too many routes/"
773                                                             "iface.\n");
774                                         return -EINVAL;
775                                 }
776                                 if (add_route)
777                                         for (ct = ntohs(nr->nr_firstnet);
778                                              ct <= limit; ct++) {
779                                                 sa->sat_addr.s_net = htons(ct);
780                                                 atrtr_create(&rtdef, dev);
781                                         }
782                         }
783                         dev_mc_add(dev, aarp_mcast, 6, 1);
784                         return 0;
785
786                 case SIOCGIFADDR:
787                         if (!atif)
788                                 return -EADDRNOTAVAIL;
789
790                         sa->sat_family = AF_APPLETALK;
791                         sa->sat_addr = atif->address;
792                         break;
793
794                 case SIOCGIFBRDADDR:
795                         if (!atif)
796                                 return -EADDRNOTAVAIL;
797
798                         sa->sat_family = AF_APPLETALK;
799                         sa->sat_addr.s_net = atif->address.s_net;
800                         sa->sat_addr.s_node = ATADDR_BCAST;
801                         break;
802
803                 case SIOCATALKDIFADDR:
804                 case SIOCDIFADDR:
805                         if (!capable(CAP_NET_ADMIN))
806                                 return -EPERM;
807                         if (sa->sat_family != AF_APPLETALK)
808                                 return -EINVAL;
809                         atalk_dev_down(dev);
810                         break;
811
812                 case SIOCSARP:
813                         if (!capable(CAP_NET_ADMIN))
814                                 return -EPERM;
815                         if (sa->sat_family != AF_APPLETALK)
816                                 return -EINVAL;
817                         /*
818                          * for now, we only support proxy AARP on ELAP;
819                          * we should be able to do it for LocalTalk, too.
820                          */
821                         if (dev->type != ARPHRD_ETHER)
822                                 return -EPROTONOSUPPORT;
823
824                         /*
825                          * atif points to the current interface on this network;
826                          * we aren't concerned about its current status (at
827                          * least for now), but it has all the settings about
828                          * the network we're going to probe. Consequently, it
829                          * must exist.
830                          */
831                         if (!atif)
832                                 return -EADDRNOTAVAIL;
833
834                         nr = (struct atalk_netrange *)&(atif->nets);
835                         /*
836                          * Phase 1 is fine on Localtalk but we don't do
837                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
838                          */
839                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
840                                 return -EPROTONOSUPPORT;
841
842                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
843                             sa->sat_addr.s_node == 254)
844                                 return -EINVAL;
845
846                         /*
847                          * Check if the chosen address is used. If so we
848                          * error and ATCP will try another.
849                          */
850                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
851                                 return -EADDRINUSE;
852
853                         /*
854                          * We now have an address on the local network, and
855                          * the AARP code will defend it for us until we take it
856                          * down. We don't set up any routes right now, because
857                          * ATCP will install them manually via SIOCADDRT.
858                          */
859                         break;
860
861                 case SIOCDARP:
862                         if (!capable(CAP_NET_ADMIN))
863                                 return -EPERM;
864                         if (sa->sat_family != AF_APPLETALK)
865                                 return -EINVAL;
866                         if (!atif)
867                                 return -EADDRNOTAVAIL;
868
869                         /* give to aarp module to remove proxy entry */
870                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
871                         return 0;
872         }
873
874         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
875 }
876
877 /* Routing ioctl() calls */
878 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
879 {
880         struct rtentry rt;
881
882         if (copy_from_user(&rt, arg, sizeof(rt)))
883                 return -EFAULT;
884
885         switch (cmd) {
886                 case SIOCDELRT:
887                         if (rt.rt_dst.sa_family != AF_APPLETALK)
888                                 return -EINVAL;
889                         return atrtr_delete(&((struct sockaddr_at *)
890                                                 &rt.rt_dst)->sat_addr);
891
892                 case SIOCADDRT: {
893                         struct net_device *dev = NULL;
894                         if (rt.rt_dev) {
895                                 char name[IFNAMSIZ];
896                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
897                                         return -EFAULT;
898                                 name[IFNAMSIZ-1] = '\0';
899                                 dev = __dev_get_by_name(&init_net, name);
900                                 if (!dev)
901                                         return -ENODEV;
902                         }
903                         return atrtr_create(&rt, dev);
904                 }
905         }
906         return -EINVAL;
907 }
908
909 /**************************************************************************\
910 *                                                                          *
911 * Handling for system calls applied via the various interfaces to an       *
912 * AppleTalk socket object.                                                 *
913 *                                                                          *
914 \**************************************************************************/
915
916 /*
917  * Checksum: This is 'optional'. It's quite likely also a good
918  * candidate for assembler hackery 8)
919  */
920 static unsigned long atalk_sum_partial(const unsigned char *data,
921                                        int len, unsigned long sum)
922 {
923         /* This ought to be unwrapped neatly. I'll trust gcc for now */
924         while (len--) {
925                 sum += *data;
926                 sum <<= 1;
927                 if (sum & 0x10000) {
928                         sum++;
929                         sum &= 0xffff;
930                 }
931                 data++;
932         }
933         return sum;
934 }
935
936 /*  Checksum skb data --  similar to skb_checksum  */
937 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
938                                    int len, unsigned long sum)
939 {
940         int start = skb_headlen(skb);
941         struct sk_buff *frag_iter;
942         int i, copy;
943
944         /* checksum stuff in header space */
945         if ( (copy = start - offset) > 0) {
946                 if (copy > len)
947                         copy = len;
948                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
949                 if ( (len -= copy) == 0)
950                         return sum;
951
952                 offset += copy;
953         }
954
955         /* checksum stuff in frags */
956         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
957                 int end;
958
959                 WARN_ON(start > offset + len);
960
961                 end = start + skb_shinfo(skb)->frags[i].size;
962                 if ((copy = end - offset) > 0) {
963                         u8 *vaddr;
964                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
965
966                         if (copy > len)
967                                 copy = len;
968                         vaddr = kmap_skb_frag(frag);
969                         sum = atalk_sum_partial(vaddr + frag->page_offset +
970                                                   offset - start, copy, sum);
971                         kunmap_skb_frag(vaddr);
972
973                         if (!(len -= copy))
974                                 return sum;
975                         offset += copy;
976                 }
977                 start = end;
978         }
979
980         skb_walk_frags(skb, frag_iter) {
981                 int end;
982
983                 WARN_ON(start > offset + len);
984
985                 end = start + frag_iter->len;
986                 if ((copy = end - offset) > 0) {
987                         if (copy > len)
988                                 copy = len;
989                         sum = atalk_sum_skb(frag_iter, offset - start,
990                                             copy, sum);
991                         if ((len -= copy) == 0)
992                                 return sum;
993                         offset += copy;
994                 }
995                 start = end;
996         }
997
998         BUG_ON(len > 0);
999
1000         return sum;
1001 }
1002
1003 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1004 {
1005         unsigned long sum;
1006
1007         /* skip header 4 bytes */
1008         sum = atalk_sum_skb(skb, 4, len-4, 0);
1009
1010         /* Use 0xFFFF for 0. 0 itself means none */
1011         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1012 }
1013
1014 static struct proto ddp_proto = {
1015         .name     = "DDP",
1016         .owner    = THIS_MODULE,
1017         .obj_size = sizeof(struct atalk_sock),
1018 };
1019
1020 /*
1021  * Create a socket. Initialise the socket, blank the addresses
1022  * set the state.
1023  */
1024 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1025 {
1026         struct sock *sk;
1027         int rc = -ESOCKTNOSUPPORT;
1028
1029         if (net != &init_net)
1030                 return -EAFNOSUPPORT;
1031
1032         /*
1033          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1034          * and gives you the full ELAP frame. Should be handy for CAP 8)
1035          */
1036         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1037                 goto out;
1038         rc = -ENOMEM;
1039         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1040         if (!sk)
1041                 goto out;
1042         rc = 0;
1043         sock->ops = &atalk_dgram_ops;
1044         sock_init_data(sock, sk);
1045
1046         /* Checksums on by default */
1047         sock_set_flag(sk, SOCK_ZAPPED);
1048 out:
1049         return rc;
1050 }
1051
1052 /* Free a socket. No work needed */
1053 static int atalk_release(struct socket *sock)
1054 {
1055         struct sock *sk = sock->sk;
1056
1057         if (sk) {
1058                 sock_orphan(sk);
1059                 sock->sk = NULL;
1060                 atalk_destroy_socket(sk);
1061         }
1062         return 0;
1063 }
1064
1065 /**
1066  * atalk_pick_and_bind_port - Pick a source port when one is not given
1067  * @sk - socket to insert into the tables
1068  * @sat - address to search for
1069  *
1070  * Pick a source port when one is not given. If we can find a suitable free
1071  * one, we insert the socket into the tables using it.
1072  *
1073  * This whole operation must be atomic.
1074  */
1075 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1076 {
1077         int retval;
1078
1079         write_lock_bh(&atalk_sockets_lock);
1080
1081         for (sat->sat_port = ATPORT_RESERVED;
1082              sat->sat_port < ATPORT_LAST;
1083              sat->sat_port++) {
1084                 struct sock *s;
1085                 struct hlist_node *node;
1086
1087                 sk_for_each(s, node, &atalk_sockets) {
1088                         struct atalk_sock *at = at_sk(s);
1089
1090                         if (at->src_net == sat->sat_addr.s_net &&
1091                             at->src_node == sat->sat_addr.s_node &&
1092                             at->src_port == sat->sat_port)
1093                                 goto try_next_port;
1094                 }
1095
1096                 /* Wheee, it's free, assign and insert. */
1097                 __atalk_insert_socket(sk);
1098                 at_sk(sk)->src_port = sat->sat_port;
1099                 retval = 0;
1100                 goto out;
1101
1102 try_next_port:;
1103         }
1104
1105         retval = -EBUSY;
1106 out:
1107         write_unlock_bh(&atalk_sockets_lock);
1108         return retval;
1109 }
1110
1111 static int atalk_autobind(struct sock *sk)
1112 {
1113         struct atalk_sock *at = at_sk(sk);
1114         struct sockaddr_at sat;
1115         struct atalk_addr *ap = atalk_find_primary();
1116         int n = -EADDRNOTAVAIL;
1117
1118         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1119                 goto out;
1120
1121         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1122         at->src_node = sat.sat_addr.s_node = ap->s_node;
1123
1124         n = atalk_pick_and_bind_port(sk, &sat);
1125         if (!n)
1126                 sock_reset_flag(sk, SOCK_ZAPPED);
1127 out:
1128         return n;
1129 }
1130
1131 /* Set the address 'our end' of the connection */
1132 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1133 {
1134         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1135         struct sock *sk = sock->sk;
1136         struct atalk_sock *at = at_sk(sk);
1137
1138         if (!sock_flag(sk, SOCK_ZAPPED) ||
1139             addr_len != sizeof(struct sockaddr_at))
1140                 return -EINVAL;
1141
1142         if (addr->sat_family != AF_APPLETALK)
1143                 return -EAFNOSUPPORT;
1144
1145         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1146                 struct atalk_addr *ap = atalk_find_primary();
1147
1148                 if (!ap)
1149                         return -EADDRNOTAVAIL;
1150
1151                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1152                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1153         } else {
1154                 if (!atalk_find_interface(addr->sat_addr.s_net,
1155                                           addr->sat_addr.s_node))
1156                         return -EADDRNOTAVAIL;
1157
1158                 at->src_net  = addr->sat_addr.s_net;
1159                 at->src_node = addr->sat_addr.s_node;
1160         }
1161
1162         if (addr->sat_port == ATADDR_ANYPORT) {
1163                 int n = atalk_pick_and_bind_port(sk, addr);
1164
1165                 if (n < 0)
1166                         return n;
1167         } else {
1168                 at->src_port = addr->sat_port;
1169
1170                 if (atalk_find_or_insert_socket(sk, addr))
1171                         return -EADDRINUSE;
1172         }
1173
1174         sock_reset_flag(sk, SOCK_ZAPPED);
1175         return 0;
1176 }
1177
1178 /* Set the address we talk to */
1179 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1180                          int addr_len, int flags)
1181 {
1182         struct sock *sk = sock->sk;
1183         struct atalk_sock *at = at_sk(sk);
1184         struct sockaddr_at *addr;
1185
1186         sk->sk_state   = TCP_CLOSE;
1187         sock->state = SS_UNCONNECTED;
1188
1189         if (addr_len != sizeof(*addr))
1190                 return -EINVAL;
1191
1192         addr = (struct sockaddr_at *)uaddr;
1193
1194         if (addr->sat_family != AF_APPLETALK)
1195                 return -EAFNOSUPPORT;
1196
1197         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1198             !sock_flag(sk, SOCK_BROADCAST)) {
1199 #if 1
1200                 printk(KERN_WARNING "%s is broken and did not set "
1201                                     "SO_BROADCAST. It will break when 2.2 is "
1202                                     "released.\n",
1203                         current->comm);
1204 #else
1205                 return -EACCES;
1206 #endif
1207         }
1208
1209         if (sock_flag(sk, SOCK_ZAPPED))
1210                 if (atalk_autobind(sk) < 0)
1211                         return -EBUSY;
1212
1213         if (!atrtr_get_dev(&addr->sat_addr))
1214                 return -ENETUNREACH;
1215
1216         at->dest_port = addr->sat_port;
1217         at->dest_net  = addr->sat_addr.s_net;
1218         at->dest_node = addr->sat_addr.s_node;
1219
1220         sock->state  = SS_CONNECTED;
1221         sk->sk_state = TCP_ESTABLISHED;
1222         return 0;
1223 }
1224
1225 /*
1226  * Find the name of an AppleTalk socket. Just copy the right
1227  * fields into the sockaddr.
1228  */
1229 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1230                          int *uaddr_len, int peer)
1231 {
1232         struct sockaddr_at sat;
1233         struct sock *sk = sock->sk;
1234         struct atalk_sock *at = at_sk(sk);
1235
1236         if (sock_flag(sk, SOCK_ZAPPED))
1237                 if (atalk_autobind(sk) < 0)
1238                         return -ENOBUFS;
1239
1240         *uaddr_len = sizeof(struct sockaddr_at);
1241         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
1242
1243         if (peer) {
1244                 if (sk->sk_state != TCP_ESTABLISHED)
1245                         return -ENOTCONN;
1246
1247                 sat.sat_addr.s_net  = at->dest_net;
1248                 sat.sat_addr.s_node = at->dest_node;
1249                 sat.sat_port        = at->dest_port;
1250         } else {
1251                 sat.sat_addr.s_net  = at->src_net;
1252                 sat.sat_addr.s_node = at->src_node;
1253                 sat.sat_port        = at->src_port;
1254         }
1255
1256         sat.sat_family = AF_APPLETALK;
1257         memcpy(uaddr, &sat, sizeof(sat));
1258         return 0;
1259 }
1260
1261 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1262 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1263 {
1264         return skb->data[12] == 22;
1265 }
1266
1267 static int handle_ip_over_ddp(struct sk_buff *skb)
1268 {
1269         struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1270         struct net_device_stats *stats;
1271
1272         /* This needs to be able to handle ipddp"N" devices */
1273         if (!dev) {
1274                 kfree_skb(skb);
1275                 return NET_RX_DROP;
1276         }
1277
1278         skb->protocol = htons(ETH_P_IP);
1279         skb_pull(skb, 13);
1280         skb->dev   = dev;
1281         skb_reset_transport_header(skb);
1282
1283         stats = netdev_priv(dev);
1284         stats->rx_packets++;
1285         stats->rx_bytes += skb->len + 13;
1286         return netif_rx(skb);  /* Send the SKB up to a higher place. */
1287 }
1288 #else
1289 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1290 #define is_ip_over_ddp(skb) 0
1291 #define handle_ip_over_ddp(skb) 0
1292 #endif
1293
1294 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1295                               struct ddpehdr *ddp, __u16 len_hops, int origlen)
1296 {
1297         struct atalk_route *rt;
1298         struct atalk_addr ta;
1299
1300         /*
1301          * Don't route multicast, etc., packets, or packets sent to "this
1302          * network"
1303          */
1304         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1305                 /*
1306                  * FIXME:
1307                  *
1308                  * Can it ever happen that a packet is from a PPP iface and
1309                  * needs to be broadcast onto the default network?
1310                  */
1311                 if (dev->type == ARPHRD_PPP)
1312                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1313                                           "packet received from PPP iface\n");
1314                 goto free_it;
1315         }
1316
1317         ta.s_net  = ddp->deh_dnet;
1318         ta.s_node = ddp->deh_dnode;
1319
1320         /* Route the packet */
1321         rt = atrtr_find(&ta);
1322         /* increment hops count */
1323         len_hops += 1 << 10;
1324         if (!rt || !(len_hops & (15 << 10)))
1325                 goto free_it;
1326
1327         /* FIXME: use skb->cb to be able to use shared skbs */
1328
1329         /*
1330          * Route goes through another gateway, so set the target to the
1331          * gateway instead.
1332          */
1333
1334         if (rt->flags & RTF_GATEWAY) {
1335                 ta.s_net  = rt->gateway.s_net;
1336                 ta.s_node = rt->gateway.s_node;
1337         }
1338
1339         /* Fix up skb->len field */
1340         skb_trim(skb, min_t(unsigned int, origlen,
1341                             (rt->dev->hard_header_len +
1342                              ddp_dl->header_length + (len_hops & 1023))));
1343
1344         /* FIXME: use skb->cb to be able to use shared skbs */
1345         ddp->deh_len_hops = htons(len_hops);
1346
1347         /*
1348          * Send the buffer onwards
1349          *
1350          * Now we must always be careful. If it's come from LocalTalk to
1351          * EtherTalk it might not fit
1352          *
1353          * Order matters here: If a packet has to be copied to make a new
1354          * headroom (rare hopefully) then it won't need unsharing.
1355          *
1356          * Note. ddp-> becomes invalid at the realloc.
1357          */
1358         if (skb_headroom(skb) < 22) {
1359                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1360                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1361                 kfree_skb(skb);
1362                 skb = nskb;
1363         } else
1364                 skb = skb_unshare(skb, GFP_ATOMIC);
1365
1366         /*
1367          * If the buffer didn't vanish into the lack of space bitbucket we can
1368          * send it.
1369          */
1370         if (skb == NULL)
1371                 goto drop;
1372
1373         if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1374                 return NET_RX_DROP;
1375         return NET_RX_SUCCESS;
1376 free_it:
1377         kfree_skb(skb);
1378 drop:
1379         return NET_RX_DROP;
1380 }
1381
1382 /**
1383  *      atalk_rcv - Receive a packet (in skb) from device dev
1384  *      @skb - packet received
1385  *      @dev - network device where the packet comes from
1386  *      @pt - packet type
1387  *
1388  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1389  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1390  *      is the DDP header, skb->len is the DDP length. The physical headers
1391  *      have been extracted. PPP should probably pass frames marked as for this
1392  *      layer.  [ie ARPHRD_ETHERTALK]
1393  */
1394 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1395                      struct packet_type *pt, struct net_device *orig_dev)
1396 {
1397         struct ddpehdr *ddp;
1398         struct sock *sock;
1399         struct atalk_iface *atif;
1400         struct sockaddr_at tosat;
1401         int origlen;
1402         __u16 len_hops;
1403
1404         if (!net_eq(dev_net(dev), &init_net))
1405                 goto drop;
1406
1407         /* Don't mangle buffer if shared */
1408         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1409                 goto out;
1410
1411         /* Size check and make sure header is contiguous */
1412         if (!pskb_may_pull(skb, sizeof(*ddp)))
1413                 goto drop;
1414
1415         ddp = ddp_hdr(skb);
1416
1417         len_hops = ntohs(ddp->deh_len_hops);
1418
1419         /* Trim buffer in case of stray trailing data */
1420         origlen = skb->len;
1421         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1422
1423         /*
1424          * Size check to see if ddp->deh_len was crap
1425          * (Otherwise we'll detonate most spectacularly
1426          * in the middle of atalk_checksum() or recvmsg()).
1427          */
1428         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1429                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1430                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1431                 goto drop;
1432         }
1433
1434         /*
1435          * Any checksums. Note we don't do htons() on this == is assumed to be
1436          * valid for net byte orders all over the networking code...
1437          */
1438         if (ddp->deh_sum &&
1439             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1440                 /* Not a valid AppleTalk frame - dustbin time */
1441                 goto drop;
1442
1443         /* Check the packet is aimed at us */
1444         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1445                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1446         else
1447                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1448
1449         if (!atif) {
1450                 /* Not ours, so we route the packet via the correct
1451                  * AppleTalk iface
1452                  */
1453                 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1454         }
1455
1456         /* if IP over DDP is not selected this code will be optimized out */
1457         if (is_ip_over_ddp(skb))
1458                 return handle_ip_over_ddp(skb);
1459         /*
1460          * Which socket - atalk_search_socket() looks for a *full match*
1461          * of the <net, node, port> tuple.
1462          */
1463         tosat.sat_addr.s_net  = ddp->deh_dnet;
1464         tosat.sat_addr.s_node = ddp->deh_dnode;
1465         tosat.sat_port        = ddp->deh_dport;
1466
1467         sock = atalk_search_socket(&tosat, atif);
1468         if (!sock) /* But not one of our sockets */
1469                 goto drop;
1470
1471         /* Queue packet (standard) */
1472         skb->sk = sock;
1473
1474         if (sock_queue_rcv_skb(sock, skb) < 0)
1475                 goto drop;
1476
1477         return NET_RX_SUCCESS;
1478
1479 drop:
1480         kfree_skb(skb);
1481 out:
1482         return NET_RX_DROP;
1483
1484 }
1485
1486 /*
1487  * Receive a LocalTalk frame. We make some demands on the caller here.
1488  * Caller must provide enough headroom on the packet to pull the short
1489  * header and append a long one.
1490  */
1491 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1492                      struct packet_type *pt, struct net_device *orig_dev)
1493 {
1494         if (!net_eq(dev_net(dev), &init_net))
1495                 goto freeit;
1496
1497         /* Expand any short form frames */
1498         if (skb_mac_header(skb)[2] == 1) {
1499                 struct ddpehdr *ddp;
1500                 /* Find our address */
1501                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1502
1503                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1504                         goto freeit;
1505
1506                 /* Don't mangle buffer if shared */
1507                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1508                         return 0;
1509
1510                 /*
1511                  * The push leaves us with a ddephdr not an shdr, and
1512                  * handily the port bytes in the right place preset.
1513                  */
1514                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1515
1516                 /* Now fill in the long header */
1517
1518                 /*
1519                  * These two first. The mac overlays the new source/dest
1520                  * network information so we MUST copy these before
1521                  * we write the network numbers !
1522                  */
1523
1524                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1525                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1526
1527                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1528                 ddp->deh_snet  = ap->s_net;
1529                 ddp->deh_sum   = 0;             /* No checksum */
1530                 /*
1531                  * Not sure about this bit...
1532                  */
1533                 /* Non routable, so force a drop if we slip up later */
1534                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1535         }
1536         skb_reset_transport_header(skb);
1537
1538         return atalk_rcv(skb, dev, pt, orig_dev);
1539 freeit:
1540         kfree_skb(skb);
1541         return 0;
1542 }
1543
1544 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1545                          size_t len)
1546 {
1547         struct sock *sk = sock->sk;
1548         struct atalk_sock *at = at_sk(sk);
1549         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1550         int flags = msg->msg_flags;
1551         int loopback = 0;
1552         struct sockaddr_at local_satalk, gsat;
1553         struct sk_buff *skb;
1554         struct net_device *dev;
1555         struct ddpehdr *ddp;
1556         int size;
1557         struct atalk_route *rt;
1558         int err;
1559
1560         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1561                 return -EINVAL;
1562
1563         if (len > DDP_MAXSZ)
1564                 return -EMSGSIZE;
1565
1566         if (usat) {
1567                 if (sock_flag(sk, SOCK_ZAPPED))
1568                         if (atalk_autobind(sk) < 0)
1569                                 return -EBUSY;
1570
1571                 if (msg->msg_namelen < sizeof(*usat) ||
1572                     usat->sat_family != AF_APPLETALK)
1573                         return -EINVAL;
1574
1575                 /* netatalk didn't implement this check */
1576                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1577                     !sock_flag(sk, SOCK_BROADCAST)) {
1578                         return -EPERM;
1579                 }
1580         } else {
1581                 if (sk->sk_state != TCP_ESTABLISHED)
1582                         return -ENOTCONN;
1583                 usat = &local_satalk;
1584                 usat->sat_family      = AF_APPLETALK;
1585                 usat->sat_port        = at->dest_port;
1586                 usat->sat_addr.s_node = at->dest_node;
1587                 usat->sat_addr.s_net  = at->dest_net;
1588         }
1589
1590         /* Build a packet */
1591         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1592
1593         /* For headers */
1594         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1595
1596         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1597                 rt = atrtr_find(&usat->sat_addr);
1598         } else {
1599                 struct atalk_addr at_hint;
1600
1601                 at_hint.s_node = 0;
1602                 at_hint.s_net  = at->src_net;
1603
1604                 rt = atrtr_find(&at_hint);
1605         }
1606         if (!rt)
1607                 return -ENETUNREACH;
1608
1609         dev = rt->dev;
1610
1611         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1612                         sk, size, dev->name);
1613
1614         size += dev->hard_header_len;
1615         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1616         if (!skb)
1617                 return err;
1618
1619         skb->sk = sk;
1620         skb_reserve(skb, ddp_dl->header_length);
1621         skb_reserve(skb, dev->hard_header_len);
1622         skb->dev = dev;
1623
1624         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1625
1626         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1627         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1628         ddp->deh_dnet  = usat->sat_addr.s_net;
1629         ddp->deh_snet  = at->src_net;
1630         ddp->deh_dnode = usat->sat_addr.s_node;
1631         ddp->deh_snode = at->src_node;
1632         ddp->deh_dport = usat->sat_port;
1633         ddp->deh_sport = at->src_port;
1634
1635         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1636
1637         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1638         if (err) {
1639                 kfree_skb(skb);
1640                 return -EFAULT;
1641         }
1642
1643         if (sk->sk_no_check == 1)
1644                 ddp->deh_sum = 0;
1645         else
1646                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1647
1648         /*
1649          * Loopback broadcast packets to non gateway targets (ie routes
1650          * to group we are in)
1651          */
1652         if (ddp->deh_dnode == ATADDR_BCAST &&
1653             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1654                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1655
1656                 if (skb2) {
1657                         loopback = 1;
1658                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1659                         /*
1660                          * If it fails it is queued/sent above in the aarp queue
1661                          */
1662                         aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1663                 }
1664         }
1665
1666         if (dev->flags & IFF_LOOPBACK || loopback) {
1667                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1668                 /* loop back */
1669                 skb_orphan(skb);
1670                 if (ddp->deh_dnode == ATADDR_BCAST) {
1671                         struct atalk_addr at_lo;
1672
1673                         at_lo.s_node = 0;
1674                         at_lo.s_net  = 0;
1675
1676                         rt = atrtr_find(&at_lo);
1677                         if (!rt) {
1678                                 kfree_skb(skb);
1679                                 return -ENETUNREACH;
1680                         }
1681                         dev = rt->dev;
1682                         skb->dev = dev;
1683                 }
1684                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1685         } else {
1686                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1687                 if (rt->flags & RTF_GATEWAY) {
1688                     gsat.sat_addr = rt->gateway;
1689                     usat = &gsat;
1690                 }
1691
1692                 /*
1693                  * If it fails it is queued/sent above in the aarp queue
1694                  */
1695                 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1696         }
1697         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1698
1699         return len;
1700 }
1701
1702 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1703                          size_t size, int flags)
1704 {
1705         struct sock *sk = sock->sk;
1706         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1707         struct ddpehdr *ddp;
1708         int copied = 0;
1709         int offset = 0;
1710         int err = 0;
1711         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1712                                                 flags & MSG_DONTWAIT, &err);
1713         if (!skb)
1714                 return err;
1715
1716         /* FIXME: use skb->cb to be able to use shared skbs */
1717         ddp = ddp_hdr(skb);
1718         copied = ntohs(ddp->deh_len_hops) & 1023;
1719
1720         if (sk->sk_type != SOCK_RAW) {
1721                 offset = sizeof(*ddp);
1722                 copied -= offset;
1723         }
1724
1725         if (copied > size) {
1726                 copied = size;
1727                 msg->msg_flags |= MSG_TRUNC;
1728         }
1729         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1730
1731         if (!err) {
1732                 if (sat) {
1733                         sat->sat_family      = AF_APPLETALK;
1734                         sat->sat_port        = ddp->deh_sport;
1735                         sat->sat_addr.s_node = ddp->deh_snode;
1736                         sat->sat_addr.s_net  = ddp->deh_snet;
1737                 }
1738                 msg->msg_namelen = sizeof(*sat);
1739         }
1740
1741         skb_free_datagram(sk, skb);     /* Free the datagram. */
1742         return err ? : copied;
1743 }
1744
1745
1746 /*
1747  * AppleTalk ioctl calls.
1748  */
1749 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1750 {
1751         int rc = -ENOIOCTLCMD;
1752         struct sock *sk = sock->sk;
1753         void __user *argp = (void __user *)arg;
1754
1755         switch (cmd) {
1756                 /* Protocol layer */
1757                 case TIOCOUTQ: {
1758                         long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1759
1760                         if (amount < 0)
1761                                 amount = 0;
1762                         rc = put_user(amount, (int __user *)argp);
1763                         break;
1764                 }
1765                 case TIOCINQ: {
1766                         /*
1767                          * These two are safe on a single CPU system as only
1768                          * user tasks fiddle here
1769                          */
1770                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1771                         long amount = 0;
1772
1773                         if (skb)
1774                                 amount = skb->len - sizeof(struct ddpehdr);
1775                         rc = put_user(amount, (int __user *)argp);
1776                         break;
1777                 }
1778                 case SIOCGSTAMP:
1779                         rc = sock_get_timestamp(sk, argp);
1780                         break;
1781                 case SIOCGSTAMPNS:
1782                         rc = sock_get_timestampns(sk, argp);
1783                         break;
1784                 /* Routing */
1785                 case SIOCADDRT:
1786                 case SIOCDELRT:
1787                         rc = -EPERM;
1788                         if (capable(CAP_NET_ADMIN))
1789                                 rc = atrtr_ioctl(cmd, argp);
1790                         break;
1791                 /* Interface */
1792                 case SIOCGIFADDR:
1793                 case SIOCSIFADDR:
1794                 case SIOCGIFBRDADDR:
1795                 case SIOCATALKDIFADDR:
1796                 case SIOCDIFADDR:
1797                 case SIOCSARP:          /* proxy AARP */
1798                 case SIOCDARP:          /* proxy AARP */
1799                         rtnl_lock();
1800                         rc = atif_ioctl(cmd, argp);
1801                         rtnl_unlock();
1802                         break;
1803         }
1804
1805         return rc;
1806 }
1807
1808
1809 #ifdef CONFIG_COMPAT
1810 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1811 {
1812         /*
1813          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1814          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1815          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1816          * here so there is no generic SIOCPROTOPRIVATE translation in the
1817          * system.
1818          */
1819         return -ENOIOCTLCMD;
1820 }
1821 #endif
1822
1823
1824 static const struct net_proto_family atalk_family_ops = {
1825         .family         = PF_APPLETALK,
1826         .create         = atalk_create,
1827         .owner          = THIS_MODULE,
1828 };
1829
1830 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1831         .family         = PF_APPLETALK,
1832         .owner          = THIS_MODULE,
1833         .release        = atalk_release,
1834         .bind           = atalk_bind,
1835         .connect        = atalk_connect,
1836         .socketpair     = sock_no_socketpair,
1837         .accept         = sock_no_accept,
1838         .getname        = atalk_getname,
1839         .poll           = datagram_poll,
1840         .ioctl          = atalk_ioctl,
1841 #ifdef CONFIG_COMPAT
1842         .compat_ioctl   = atalk_compat_ioctl,
1843 #endif
1844         .listen         = sock_no_listen,
1845         .shutdown       = sock_no_shutdown,
1846         .setsockopt     = sock_no_setsockopt,
1847         .getsockopt     = sock_no_getsockopt,
1848         .sendmsg        = atalk_sendmsg,
1849         .recvmsg        = atalk_recvmsg,
1850         .mmap           = sock_no_mmap,
1851         .sendpage       = sock_no_sendpage,
1852 };
1853
1854 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1855
1856 static struct notifier_block ddp_notifier = {
1857         .notifier_call  = ddp_device_event,
1858 };
1859
1860 static struct packet_type ltalk_packet_type __read_mostly = {
1861         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1862         .func           = ltalk_rcv,
1863 };
1864
1865 static struct packet_type ppptalk_packet_type __read_mostly = {
1866         .type           = cpu_to_be16(ETH_P_PPPTALK),
1867         .func           = atalk_rcv,
1868 };
1869
1870 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1871
1872 /* Export symbols for use by drivers when AppleTalk is a module */
1873 EXPORT_SYMBOL(atrtr_get_dev);
1874 EXPORT_SYMBOL(atalk_find_dev_addr);
1875
1876 static const char atalk_err_snap[] __initconst =
1877         KERN_CRIT "Unable to register DDP with SNAP.\n";
1878
1879 /* Called by proto.c on kernel start up */
1880 static int __init atalk_init(void)
1881 {
1882         int rc = proto_register(&ddp_proto, 0);
1883
1884         if (rc != 0)
1885                 goto out;
1886
1887         (void)sock_register(&atalk_family_ops);
1888         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1889         if (!ddp_dl)
1890                 printk(atalk_err_snap);
1891
1892         dev_add_pack(&ltalk_packet_type);
1893         dev_add_pack(&ppptalk_packet_type);
1894
1895         register_netdevice_notifier(&ddp_notifier);
1896         aarp_proto_init();
1897         atalk_proc_init();
1898         atalk_register_sysctl();
1899 out:
1900         return rc;
1901 }
1902 module_init(atalk_init);
1903
1904 /*
1905  * No explicit module reference count manipulation is needed in the
1906  * protocol. Socket layer sets module reference count for us
1907  * and interfaces reference counting is done
1908  * by the network device layer.
1909  *
1910  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1911  * sockets be closed from user space.
1912  */
1913 static void __exit atalk_exit(void)
1914 {
1915 #ifdef CONFIG_SYSCTL
1916         atalk_unregister_sysctl();
1917 #endif /* CONFIG_SYSCTL */
1918         atalk_proc_exit();
1919         aarp_cleanup_module();  /* General aarp clean-up. */
1920         unregister_netdevice_notifier(&ddp_notifier);
1921         dev_remove_pack(&ltalk_packet_type);
1922         dev_remove_pack(&ppptalk_packet_type);
1923         unregister_snap_client(ddp_dl);
1924         sock_unregister(PF_APPLETALK);
1925         proto_unregister(&ddp_proto);
1926 }
1927 module_exit(atalk_exit);
1928
1929 MODULE_LICENSE("GPL");
1930 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1931 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1932 MODULE_ALIAS_NETPROTO(PF_APPLETALK);