header cleaning: don't include smp_lock.h when not used
[linux-3.10.git] / net / appletalk / ddp.c
1 /*
2  *      DDP:    An implementation of the AppleTalk DDP protocol for
3  *              Ethernet 'ELAP'.
4  *
5  *              Alan Cox  <Alan.Cox@linux.org>
6  *
7  *              With more than a little assistance from
8  *
9  *              Wesley Craig <netatalk@umich.edu>
10  *
11  *      Fixes:
12  *              Neil Horman             :       Added missing device ioctls
13  *              Michael Callahan        :       Made routing work
14  *              Wesley Craig            :       Fix probing to listen to a
15  *                                              passed node id.
16  *              Alan Cox                :       Added send/recvmsg support
17  *              Alan Cox                :       Moved at. to protinfo in
18  *                                              socket.
19  *              Alan Cox                :       Added firewall hooks.
20  *              Alan Cox                :       Supports new ARPHRD_LOOPBACK
21  *              Christer Weinigel       :       Routing and /proc fixes.
22  *              Bradford Johnson        :       LocalTalk.
23  *              Tom Dyas                :       Module support.
24  *              Alan Cox                :       Hooks for PPP (based on the
25  *                                              LocalTalk hook).
26  *              Alan Cox                :       Posix bits
27  *              Alan Cox/Mike Freeman   :       Possible fix to NBP problems
28  *              Bradford Johnson        :       IP-over-DDP (experimental)
29  *              Jay Schulist            :       Moved IP-over-DDP to its own
30  *                                              driver file. (ipddp.c & ipddp.h)
31  *              Jay Schulist            :       Made work as module with
32  *                                              AppleTalk drivers, cleaned it.
33  *              Rob Newberry            :       Added proxy AARP and AARP
34  *                                              procfs, moved probing to AARP
35  *                                              module.
36  *              Adrian Sun/
37  *              Michael Zuelsdorff      :       fix for net.0 packets. don't
38  *                                              allow illegal ether/tokentalk
39  *                                              port assignment. we lose a
40  *                                              valid localtalk port as a
41  *                                              result.
42  *              Arnaldo C. de Melo      :       Cleanup, in preparation for
43  *                                              shared skb support 8)
44  *              Arnaldo C. de Melo      :       Move proc stuff to atalk_proc.c,
45  *                                              use seq_file
46  *
47  *              This program is free software; you can redistribute it and/or
48  *              modify it under the terms of the GNU General Public License
49  *              as published by the Free Software Foundation; either version
50  *              2 of the License, or (at your option) any later version.
51  *
52  */
53
54 #include <linux/capability.h>
55 #include <linux/module.h>
56 #include <linux/if_arp.h>
57 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
58 #include <net/datalink.h>
59 #include <net/psnap.h>
60 #include <net/sock.h>
61 #include <net/tcp_states.h>
62 #include <net/route.h>
63 #include <linux/atalk.h>
64 #include "../core/kmap_skb.h"
65
66 struct datalink_proto *ddp_dl, *aarp_dl;
67 static const struct proto_ops atalk_dgram_ops;
68
69 /**************************************************************************\
70 *                                                                          *
71 * Handlers for the socket list.                                            *
72 *                                                                          *
73 \**************************************************************************/
74
75 HLIST_HEAD(atalk_sockets);
76 DEFINE_RWLOCK(atalk_sockets_lock);
77
78 static inline void __atalk_insert_socket(struct sock *sk)
79 {
80         sk_add_node(sk, &atalk_sockets);
81 }
82
83 static inline void atalk_remove_socket(struct sock *sk)
84 {
85         write_lock_bh(&atalk_sockets_lock);
86         sk_del_node_init(sk);
87         write_unlock_bh(&atalk_sockets_lock);
88 }
89
90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
91                                         struct atalk_iface *atif)
92 {
93         struct sock *s;
94         struct hlist_node *node;
95
96         read_lock_bh(&atalk_sockets_lock);
97         sk_for_each(s, node, &atalk_sockets) {
98                 struct atalk_sock *at = at_sk(s);
99
100                 if (to->sat_port != at->src_port)
101                         continue;
102
103                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
104                     to->sat_addr.s_node == ATADDR_BCAST)
105                         goto found;
106
107                 if (to->sat_addr.s_net == at->src_net &&
108                     (to->sat_addr.s_node == at->src_node ||
109                      to->sat_addr.s_node == ATADDR_BCAST ||
110                      to->sat_addr.s_node == ATADDR_ANYNODE))
111                         goto found;
112
113                 /* XXXX.0 -- we got a request for this router. make sure
114                  * that the node is appropriately set. */
115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
116                     to->sat_addr.s_net != ATADDR_ANYNET &&
117                     atif->address.s_node == at->src_node) {
118                         to->sat_addr.s_node = atif->address.s_node;
119                         goto found;
120                 }
121         }
122         s = NULL;
123 found:
124         read_unlock_bh(&atalk_sockets_lock);
125         return s;
126 }
127
128 /**
129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
130  * @sk - socket to insert in the list if it is not there already
131  * @sat - address to search for
132  *
133  * Try to find a socket matching ADDR in the socket list, if found then return
134  * it. If not, insert SK into the socket list.
135  *
136  * This entire operation must execute atomically.
137  */
138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
139                                                 struct sockaddr_at *sat)
140 {
141         struct sock *s;
142         struct hlist_node *node;
143         struct atalk_sock *at;
144
145         write_lock_bh(&atalk_sockets_lock);
146         sk_for_each(s, node, &atalk_sockets) {
147                 at = at_sk(s);
148
149                 if (at->src_net == sat->sat_addr.s_net &&
150                     at->src_node == sat->sat_addr.s_node &&
151                     at->src_port == sat->sat_port)
152                         goto found;
153         }
154         s = NULL;
155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
156 found:
157         write_unlock_bh(&atalk_sockets_lock);
158         return s;
159 }
160
161 static void atalk_destroy_timer(unsigned long data)
162 {
163         struct sock *sk = (struct sock *)data;
164
165         if (atomic_read(&sk->sk_wmem_alloc) ||
166             atomic_read(&sk->sk_rmem_alloc)) {
167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
168                 add_timer(&sk->sk_timer);
169         } else
170                 sock_put(sk);
171 }
172
173 static inline void atalk_destroy_socket(struct sock *sk)
174 {
175         atalk_remove_socket(sk);
176         skb_queue_purge(&sk->sk_receive_queue);
177
178         if (atomic_read(&sk->sk_wmem_alloc) ||
179             atomic_read(&sk->sk_rmem_alloc)) {
180                 init_timer(&sk->sk_timer);
181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
182                 sk->sk_timer.function   = atalk_destroy_timer;
183                 sk->sk_timer.data       = (unsigned long)sk;
184                 add_timer(&sk->sk_timer);
185         } else
186                 sock_put(sk);
187 }
188
189 /**************************************************************************\
190 *                                                                          *
191 * Routing tables for the AppleTalk socket layer.                           *
192 *                                                                          *
193 \**************************************************************************/
194
195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
196 struct atalk_route *atalk_routes;
197 DEFINE_RWLOCK(atalk_routes_lock);
198
199 struct atalk_iface *atalk_interfaces;
200 DEFINE_RWLOCK(atalk_interfaces_lock);
201
202 /* For probing devices or in a routerless network */
203 struct atalk_route atrtr_default;
204
205 /* AppleTalk interface control */
206 /*
207  * Drop a device. Doesn't drop any of its routes - that is the caller's
208  * problem. Called when we down the interface or delete the address.
209  */
210 static void atif_drop_device(struct net_device *dev)
211 {
212         struct atalk_iface **iface = &atalk_interfaces;
213         struct atalk_iface *tmp;
214
215         write_lock_bh(&atalk_interfaces_lock);
216         while ((tmp = *iface) != NULL) {
217                 if (tmp->dev == dev) {
218                         *iface = tmp->next;
219                         dev_put(dev);
220                         kfree(tmp);
221                         dev->atalk_ptr = NULL;
222                 } else
223                         iface = &tmp->next;
224         }
225         write_unlock_bh(&atalk_interfaces_lock);
226 }
227
228 static struct atalk_iface *atif_add_device(struct net_device *dev,
229                                            struct atalk_addr *sa)
230 {
231         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
232
233         if (!iface)
234                 goto out;
235
236         dev_hold(dev);
237         iface->dev = dev;
238         dev->atalk_ptr = iface;
239         iface->address = *sa;
240         iface->status = 0;
241
242         write_lock_bh(&atalk_interfaces_lock);
243         iface->next = atalk_interfaces;
244         atalk_interfaces = iface;
245         write_unlock_bh(&atalk_interfaces_lock);
246 out:
247         return iface;
248 }
249
250 /* Perform phase 2 AARP probing on our tentative address */
251 static int atif_probe_device(struct atalk_iface *atif)
252 {
253         int netrange = ntohs(atif->nets.nr_lastnet) -
254                         ntohs(atif->nets.nr_firstnet) + 1;
255         int probe_net = ntohs(atif->address.s_net);
256         int probe_node = atif->address.s_node;
257         int netct, nodect;
258
259         /* Offset the network we start probing with */
260         if (probe_net == ATADDR_ANYNET) {
261                 probe_net = ntohs(atif->nets.nr_firstnet);
262                 if (netrange)
263                         probe_net += jiffies % netrange;
264         }
265         if (probe_node == ATADDR_ANYNODE)
266                 probe_node = jiffies & 0xFF;
267
268         /* Scan the networks */
269         atif->status |= ATIF_PROBE;
270         for (netct = 0; netct <= netrange; netct++) {
271                 /* Sweep the available nodes from a given start */
272                 atif->address.s_net = htons(probe_net);
273                 for (nodect = 0; nodect < 256; nodect++) {
274                         atif->address.s_node = (nodect + probe_node) & 0xFF;
275                         if (atif->address.s_node > 0 &&
276                             atif->address.s_node < 254) {
277                                 /* Probe a proposed address */
278                                 aarp_probe_network(atif);
279
280                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
281                                         atif->status &= ~ATIF_PROBE;
282                                         return 0;
283                                 }
284                         }
285                         atif->status &= ~ATIF_PROBE_FAIL;
286                 }
287                 probe_net++;
288                 if (probe_net > ntohs(atif->nets.nr_lastnet))
289                         probe_net = ntohs(atif->nets.nr_firstnet);
290         }
291         atif->status &= ~ATIF_PROBE;
292
293         return -EADDRINUSE;     /* Network is full... */
294 }
295
296
297 /* Perform AARP probing for a proxy address */
298 static int atif_proxy_probe_device(struct atalk_iface *atif,
299                                    struct atalk_addr* proxy_addr)
300 {
301         int netrange = ntohs(atif->nets.nr_lastnet) -
302                         ntohs(atif->nets.nr_firstnet) + 1;
303         /* we probe the interface's network */
304         int probe_net = ntohs(atif->address.s_net);
305         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
306         int netct, nodect;
307
308         /* Offset the network we start probing with */
309         if (probe_net == ATADDR_ANYNET) {
310                 probe_net = ntohs(atif->nets.nr_firstnet);
311                 if (netrange)
312                         probe_net += jiffies % netrange;
313         }
314
315         if (probe_node == ATADDR_ANYNODE)
316                 probe_node = jiffies & 0xFF;
317
318         /* Scan the networks */
319         for (netct = 0; netct <= netrange; netct++) {
320                 /* Sweep the available nodes from a given start */
321                 proxy_addr->s_net = htons(probe_net);
322                 for (nodect = 0; nodect < 256; nodect++) {
323                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
324                         if (proxy_addr->s_node > 0 &&
325                             proxy_addr->s_node < 254) {
326                                 /* Tell AARP to probe a proposed address */
327                                 int ret = aarp_proxy_probe_network(atif,
328                                                                     proxy_addr);
329
330                                 if (ret != -EADDRINUSE)
331                                         return ret;
332                         }
333                 }
334                 probe_net++;
335                 if (probe_net > ntohs(atif->nets.nr_lastnet))
336                         probe_net = ntohs(atif->nets.nr_firstnet);
337         }
338
339         return -EADDRINUSE;     /* Network is full... */
340 }
341
342
343 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
344 {
345         struct atalk_iface *iface = dev->atalk_ptr;
346         return iface ? &iface->address : NULL;
347 }
348
349 static struct atalk_addr *atalk_find_primary(void)
350 {
351         struct atalk_iface *fiface = NULL;
352         struct atalk_addr *retval;
353         struct atalk_iface *iface;
354
355         /*
356          * Return a point-to-point interface only if
357          * there is no non-ptp interface available.
358          */
359         read_lock_bh(&atalk_interfaces_lock);
360         for (iface = atalk_interfaces; iface; iface = iface->next) {
361                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
362                         fiface = iface;
363                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
364                         retval = &iface->address;
365                         goto out;
366                 }
367         }
368
369         if (fiface)
370                 retval = &fiface->address;
371         else if (atalk_interfaces)
372                 retval = &atalk_interfaces->address;
373         else
374                 retval = NULL;
375 out:
376         read_unlock_bh(&atalk_interfaces_lock);
377         return retval;
378 }
379
380 /*
381  * Find a match for 'any network' - ie any of our interfaces with that
382  * node number will do just nicely.
383  */
384 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
385 {
386         struct atalk_iface *iface = dev->atalk_ptr;
387
388         if (!iface || iface->status & ATIF_PROBE)
389                 goto out_err;
390
391         if (node != ATADDR_BCAST &&
392             iface->address.s_node != node &&
393             node != ATADDR_ANYNODE)
394                 goto out_err;
395 out:
396         return iface;
397 out_err:
398         iface = NULL;
399         goto out;
400 }
401
402 /* Find a match for a specific network:node pair */
403 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
404 {
405         struct atalk_iface *iface;
406
407         read_lock_bh(&atalk_interfaces_lock);
408         for (iface = atalk_interfaces; iface; iface = iface->next) {
409                 if ((node == ATADDR_BCAST ||
410                      node == ATADDR_ANYNODE ||
411                      iface->address.s_node == node) &&
412                     iface->address.s_net == net &&
413                     !(iface->status & ATIF_PROBE))
414                         break;
415
416                 /* XXXX.0 -- net.0 returns the iface associated with net */
417                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
418                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
419                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
420                         break;
421         }
422         read_unlock_bh(&atalk_interfaces_lock);
423         return iface;
424 }
425
426
427 /*
428  * Find a route for an AppleTalk packet. This ought to get cached in
429  * the socket (later on...). We know about host routes and the fact
430  * that a route must be direct to broadcast.
431  */
432 static struct atalk_route *atrtr_find(struct atalk_addr *target)
433 {
434         /*
435          * we must search through all routes unless we find a
436          * host route, because some host routes might overlap
437          * network routes
438          */
439         struct atalk_route *net_route = NULL;
440         struct atalk_route *r;
441
442         read_lock_bh(&atalk_routes_lock);
443         for (r = atalk_routes; r; r = r->next) {
444                 if (!(r->flags & RTF_UP))
445                         continue;
446
447                 if (r->target.s_net == target->s_net) {
448                         if (r->flags & RTF_HOST) {
449                                 /*
450                                  * if this host route is for the target,
451                                  * the we're done
452                                  */
453                                 if (r->target.s_node == target->s_node)
454                                         goto out;
455                         } else
456                                 /*
457                                  * this route will work if there isn't a
458                                  * direct host route, so cache it
459                                  */
460                                 net_route = r;
461                 }
462         }
463
464         /*
465          * if we found a network route but not a direct host
466          * route, then return it
467          */
468         if (net_route)
469                 r = net_route;
470         else if (atrtr_default.dev)
471                 r = &atrtr_default;
472         else /* No route can be found */
473                 r = NULL;
474 out:
475         read_unlock_bh(&atalk_routes_lock);
476         return r;
477 }
478
479
480 /*
481  * Given an AppleTalk network, find the device to use. This can be
482  * a simple lookup.
483  */
484 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
485 {
486         struct atalk_route *atr = atrtr_find(sa);
487         return atr ? atr->dev : NULL;
488 }
489
490 /* Set up a default router */
491 static void atrtr_set_default(struct net_device *dev)
492 {
493         atrtr_default.dev            = dev;
494         atrtr_default.flags          = RTF_UP;
495         atrtr_default.gateway.s_net  = htons(0);
496         atrtr_default.gateway.s_node = 0;
497 }
498
499 /*
500  * Add a router. Basically make sure it looks valid and stuff the
501  * entry in the list. While it uses netranges we always set them to one
502  * entry to work like netatalk.
503  */
504 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
505 {
506         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
507         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
508         struct atalk_route *rt;
509         struct atalk_iface *iface, *riface;
510         int retval = -EINVAL;
511
512         /*
513          * Fixme: Raise/Lower a routing change semaphore for these
514          * operations.
515          */
516
517         /* Validate the request */
518         if (ta->sat_family != AF_APPLETALK ||
519             (!devhint && ga->sat_family != AF_APPLETALK))
520                 goto out;
521
522         /* Now walk the routing table and make our decisions */
523         write_lock_bh(&atalk_routes_lock);
524         for (rt = atalk_routes; rt; rt = rt->next) {
525                 if (r->rt_flags != rt->flags)
526                         continue;
527
528                 if (ta->sat_addr.s_net == rt->target.s_net) {
529                         if (!(rt->flags & RTF_HOST))
530                                 break;
531                         if (ta->sat_addr.s_node == rt->target.s_node)
532                                 break;
533                 }
534         }
535
536         if (!devhint) {
537                 riface = NULL;
538
539                 read_lock_bh(&atalk_interfaces_lock);
540                 for (iface = atalk_interfaces; iface; iface = iface->next) {
541                         if (!riface &&
542                             ntohs(ga->sat_addr.s_net) >=
543                                         ntohs(iface->nets.nr_firstnet) &&
544                             ntohs(ga->sat_addr.s_net) <=
545                                         ntohs(iface->nets.nr_lastnet))
546                                 riface = iface;
547
548                         if (ga->sat_addr.s_net == iface->address.s_net &&
549                             ga->sat_addr.s_node == iface->address.s_node)
550                                 riface = iface;
551                 }
552                 read_unlock_bh(&atalk_interfaces_lock);
553
554                 retval = -ENETUNREACH;
555                 if (!riface)
556                         goto out_unlock;
557
558                 devhint = riface->dev;
559         }
560
561         if (!rt) {
562                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
563
564                 retval = -ENOBUFS;
565                 if (!rt)
566                         goto out_unlock;
567
568                 rt->next = atalk_routes;
569                 atalk_routes = rt;
570         }
571
572         /* Fill in the routing entry */
573         rt->target  = ta->sat_addr;
574         dev_hold(devhint);
575         rt->dev     = devhint;
576         rt->flags   = r->rt_flags;
577         rt->gateway = ga->sat_addr;
578
579         retval = 0;
580 out_unlock:
581         write_unlock_bh(&atalk_routes_lock);
582 out:
583         return retval;
584 }
585
586 /* Delete a route. Find it and discard it */
587 static int atrtr_delete(struct atalk_addr * addr)
588 {
589         struct atalk_route **r = &atalk_routes;
590         int retval = 0;
591         struct atalk_route *tmp;
592
593         write_lock_bh(&atalk_routes_lock);
594         while ((tmp = *r) != NULL) {
595                 if (tmp->target.s_net == addr->s_net &&
596                     (!(tmp->flags&RTF_GATEWAY) ||
597                      tmp->target.s_node == addr->s_node)) {
598                         *r = tmp->next;
599                         dev_put(tmp->dev);
600                         kfree(tmp);
601                         goto out;
602                 }
603                 r = &tmp->next;
604         }
605         retval = -ENOENT;
606 out:
607         write_unlock_bh(&atalk_routes_lock);
608         return retval;
609 }
610
611 /*
612  * Called when a device is downed. Just throw away any routes
613  * via it.
614  */
615 static void atrtr_device_down(struct net_device *dev)
616 {
617         struct atalk_route **r = &atalk_routes;
618         struct atalk_route *tmp;
619
620         write_lock_bh(&atalk_routes_lock);
621         while ((tmp = *r) != NULL) {
622                 if (tmp->dev == dev) {
623                         *r = tmp->next;
624                         dev_put(dev);
625                         kfree(tmp);
626                 } else
627                         r = &tmp->next;
628         }
629         write_unlock_bh(&atalk_routes_lock);
630
631         if (atrtr_default.dev == dev)
632                 atrtr_set_default(NULL);
633 }
634
635 /* Actually down the interface */
636 static inline void atalk_dev_down(struct net_device *dev)
637 {
638         atrtr_device_down(dev); /* Remove all routes for the device */
639         aarp_device_down(dev);  /* Remove AARP entries for the device */
640         atif_drop_device(dev);  /* Remove the device */
641 }
642
643 /*
644  * A device event has occurred. Watch for devices going down and
645  * delete our use of them (iface and route).
646  */
647 static int ddp_device_event(struct notifier_block *this, unsigned long event,
648                             void *ptr)
649 {
650         if (event == NETDEV_DOWN)
651                 /* Discard any use of this */
652                 atalk_dev_down(ptr);
653
654         return NOTIFY_DONE;
655 }
656
657 /* ioctl calls. Shouldn't even need touching */
658 /* Device configuration ioctl calls */
659 static int atif_ioctl(int cmd, void __user *arg)
660 {
661         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
662         struct ifreq atreq;
663         struct atalk_netrange *nr;
664         struct sockaddr_at *sa;
665         struct net_device *dev;
666         struct atalk_iface *atif;
667         int ct;
668         int limit;
669         struct rtentry rtdef;
670         int add_route;
671
672         if (copy_from_user(&atreq, arg, sizeof(atreq)))
673                 return -EFAULT;
674
675         dev = __dev_get_by_name(atreq.ifr_name);
676         if (!dev)
677                 return -ENODEV;
678
679         sa = (struct sockaddr_at *)&atreq.ifr_addr;
680         atif = atalk_find_dev(dev);
681
682         switch (cmd) {
683                 case SIOCSIFADDR:
684                         if (!capable(CAP_NET_ADMIN))
685                                 return -EPERM;
686                         if (sa->sat_family != AF_APPLETALK)
687                                 return -EINVAL;
688                         if (dev->type != ARPHRD_ETHER &&
689                             dev->type != ARPHRD_LOOPBACK &&
690                             dev->type != ARPHRD_LOCALTLK &&
691                             dev->type != ARPHRD_PPP)
692                                 return -EPROTONOSUPPORT;
693
694                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
695                         add_route = 1;
696
697                         /*
698                          * if this is a point-to-point iface, and we already
699                          * have an iface for this AppleTalk address, then we
700                          * should not add a route
701                          */
702                         if ((dev->flags & IFF_POINTOPOINT) &&
703                             atalk_find_interface(sa->sat_addr.s_net,
704                                                  sa->sat_addr.s_node)) {
705                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
706                                                   "interface added with "
707                                                   "existing address\n");
708                                 add_route = 0;
709                         }
710
711                         /*
712                          * Phase 1 is fine on LocalTalk but we don't do
713                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
714                          */
715                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
716                                 return -EPROTONOSUPPORT;
717                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
718                             sa->sat_addr.s_node == 254)
719                                 return -EINVAL;
720                         if (atif) {
721                                 /* Already setting address */
722                                 if (atif->status & ATIF_PROBE)
723                                         return -EBUSY;
724
725                                 atif->address.s_net  = sa->sat_addr.s_net;
726                                 atif->address.s_node = sa->sat_addr.s_node;
727                                 atrtr_device_down(dev); /* Flush old routes */
728                         } else {
729                                 atif = atif_add_device(dev, &sa->sat_addr);
730                                 if (!atif)
731                                         return -ENOMEM;
732                         }
733                         atif->nets = *nr;
734
735                         /*
736                          * Check if the chosen address is used. If so we
737                          * error and atalkd will try another.
738                          */
739
740                         if (!(dev->flags & IFF_LOOPBACK) &&
741                             !(dev->flags & IFF_POINTOPOINT) &&
742                             atif_probe_device(atif) < 0) {
743                                 atif_drop_device(dev);
744                                 return -EADDRINUSE;
745                         }
746
747                         /* Hey it worked - add the direct routes */
748                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
749                         sa->sat_family = AF_APPLETALK;
750                         sa->sat_addr.s_net  = atif->address.s_net;
751                         sa->sat_addr.s_node = atif->address.s_node;
752                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
753                         rtdef.rt_flags = RTF_UP;
754                         sa->sat_family = AF_APPLETALK;
755                         sa->sat_addr.s_node = ATADDR_ANYNODE;
756                         if (dev->flags & IFF_LOOPBACK ||
757                             dev->flags & IFF_POINTOPOINT)
758                                 rtdef.rt_flags |= RTF_HOST;
759
760                         /* Routerless initial state */
761                         if (nr->nr_firstnet == htons(0) &&
762                             nr->nr_lastnet == htons(0xFFFE)) {
763                                 sa->sat_addr.s_net = atif->address.s_net;
764                                 atrtr_create(&rtdef, dev);
765                                 atrtr_set_default(dev);
766                         } else {
767                                 limit = ntohs(nr->nr_lastnet);
768                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
769                                         printk(KERN_WARNING "Too many routes/"
770                                                             "iface.\n");
771                                         return -EINVAL;
772                                 }
773                                 if (add_route)
774                                         for (ct = ntohs(nr->nr_firstnet);
775                                              ct <= limit; ct++) {
776                                                 sa->sat_addr.s_net = htons(ct);
777                                                 atrtr_create(&rtdef, dev);
778                                         }
779                         }
780                         dev_mc_add(dev, aarp_mcast, 6, 1);
781                         return 0;
782
783                 case SIOCGIFADDR:
784                         if (!atif)
785                                 return -EADDRNOTAVAIL;
786
787                         sa->sat_family = AF_APPLETALK;
788                         sa->sat_addr = atif->address;
789                         break;
790
791                 case SIOCGIFBRDADDR:
792                         if (!atif)
793                                 return -EADDRNOTAVAIL;
794
795                         sa->sat_family = AF_APPLETALK;
796                         sa->sat_addr.s_net = atif->address.s_net;
797                         sa->sat_addr.s_node = ATADDR_BCAST;
798                         break;
799
800                 case SIOCATALKDIFADDR:
801                 case SIOCDIFADDR:
802                         if (!capable(CAP_NET_ADMIN))
803                                 return -EPERM;
804                         if (sa->sat_family != AF_APPLETALK)
805                                 return -EINVAL;
806                         atalk_dev_down(dev);
807                         break;
808
809                 case SIOCSARP:
810                         if (!capable(CAP_NET_ADMIN))
811                                 return -EPERM;
812                         if (sa->sat_family != AF_APPLETALK)
813                                 return -EINVAL;
814                         if (!atif)
815                                 return -EADDRNOTAVAIL;
816
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(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         int i, copy;
942
943         /* checksum stuff in header space */
944         if ( (copy = start - offset) > 0) {
945                 if (copy > len)
946                         copy = len;
947                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
948                 if ( (len -= copy) == 0)
949                         return sum;
950
951                 offset += copy;
952         }
953
954         /* checksum stuff in frags */
955         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
956                 int end;
957
958                 BUG_TRAP(start <= offset + len);
959
960                 end = start + skb_shinfo(skb)->frags[i].size;
961                 if ((copy = end - offset) > 0) {
962                         u8 *vaddr;
963                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
964
965                         if (copy > len)
966                                 copy = len;
967                         vaddr = kmap_skb_frag(frag);
968                         sum = atalk_sum_partial(vaddr + frag->page_offset +
969                                                   offset - start, copy, sum);
970                         kunmap_skb_frag(vaddr);
971
972                         if (!(len -= copy))
973                                 return sum;
974                         offset += copy;
975                 }
976                 start = end;
977         }
978
979         if (skb_shinfo(skb)->frag_list) {
980                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
981
982                 for (; list; list = list->next) {
983                         int end;
984
985                         BUG_TRAP(start <= offset + len);
986
987                         end = start + list->len;
988                         if ((copy = end - offset) > 0) {
989                                 if (copy > len)
990                                         copy = len;
991                                 sum = atalk_sum_skb(list, offset - start,
992                                                     copy, sum);
993                                 if ((len -= copy) == 0)
994                                         return sum;
995                                 offset += copy;
996                         }
997                         start = end;
998                 }
999         }
1000
1001         BUG_ON(len > 0);
1002
1003         return sum;
1004 }
1005
1006 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1007 {
1008         unsigned long sum;
1009
1010         /* skip header 4 bytes */
1011         sum = atalk_sum_skb(skb, 4, len-4, 0);
1012
1013         /* Use 0xFFFF for 0. 0 itself means none */
1014         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1015 }
1016
1017 static struct proto ddp_proto = {
1018         .name     = "DDP",
1019         .owner    = THIS_MODULE,
1020         .obj_size = sizeof(struct atalk_sock),
1021 };
1022
1023 /*
1024  * Create a socket. Initialise the socket, blank the addresses
1025  * set the state.
1026  */
1027 static int atalk_create(struct socket *sock, int protocol)
1028 {
1029         struct sock *sk;
1030         int rc = -ESOCKTNOSUPPORT;
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(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
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
1242         if (peer) {
1243                 if (sk->sk_state != TCP_ESTABLISHED)
1244                         return -ENOTCONN;
1245
1246                 sat.sat_addr.s_net  = at->dest_net;
1247                 sat.sat_addr.s_node = at->dest_node;
1248                 sat.sat_port        = at->dest_port;
1249         } else {
1250                 sat.sat_addr.s_net  = at->src_net;
1251                 sat.sat_addr.s_node = at->src_node;
1252                 sat.sat_port        = at->src_port;
1253         }
1254
1255         sat.sat_family = AF_APPLETALK;
1256         memcpy(uaddr, &sat, sizeof(sat));
1257         return 0;
1258 }
1259
1260 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1261 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1262 {
1263         return skb->data[12] == 22;
1264 }
1265
1266 static int handle_ip_over_ddp(struct sk_buff *skb)
1267 {
1268         struct net_device *dev = __dev_get_by_name("ipddp0");
1269         struct net_device_stats *stats;
1270
1271         /* This needs to be able to handle ipddp"N" devices */
1272         if (!dev)
1273                 return -ENODEV;
1274
1275         skb->protocol = htons(ETH_P_IP);
1276         skb_pull(skb, 13);
1277         skb->dev   = dev;
1278         skb_reset_transport_header(skb);
1279
1280         stats = dev->priv;
1281         stats->rx_packets++;
1282         stats->rx_bytes += skb->len + 13;
1283         netif_rx(skb);  /* Send the SKB up to a higher place. */
1284         return 0;
1285 }
1286 #else
1287 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1288 #define is_ip_over_ddp(skb) 0
1289 #define handle_ip_over_ddp(skb) 0
1290 #endif
1291
1292 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1293                                struct ddpehdr *ddp, __u16 len_hops,
1294                                int origlen)
1295 {
1296         struct atalk_route *rt;
1297         struct atalk_addr ta;
1298
1299         /*
1300          * Don't route multicast, etc., packets, or packets sent to "this
1301          * network"
1302          */
1303         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1304                 /*
1305                  * FIXME:
1306                  *
1307                  * Can it ever happen that a packet is from a PPP iface and
1308                  * needs to be broadcast onto the default network?
1309                  */
1310                 if (dev->type == ARPHRD_PPP)
1311                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1312                                           "packet received from PPP iface\n");
1313                 goto free_it;
1314         }
1315
1316         ta.s_net  = ddp->deh_dnet;
1317         ta.s_node = ddp->deh_dnode;
1318
1319         /* Route the packet */
1320         rt = atrtr_find(&ta);
1321         /* increment hops count */
1322         len_hops += 1 << 10;
1323         if (!rt || !(len_hops & (15 << 10)))
1324                 goto free_it;
1325
1326         /* FIXME: use skb->cb to be able to use shared skbs */
1327
1328         /*
1329          * Route goes through another gateway, so set the target to the
1330          * gateway instead.
1331          */
1332
1333         if (rt->flags & RTF_GATEWAY) {
1334                 ta.s_net  = rt->gateway.s_net;
1335                 ta.s_node = rt->gateway.s_node;
1336         }
1337
1338         /* Fix up skb->len field */
1339         skb_trim(skb, min_t(unsigned int, origlen,
1340                             (rt->dev->hard_header_len +
1341                              ddp_dl->header_length + (len_hops & 1023))));
1342
1343         /* FIXME: use skb->cb to be able to use shared skbs */
1344         ddp->deh_len_hops = htons(len_hops);
1345
1346         /*
1347          * Send the buffer onwards
1348          *
1349          * Now we must always be careful. If it's come from LocalTalk to
1350          * EtherTalk it might not fit
1351          *
1352          * Order matters here: If a packet has to be copied to make a new
1353          * headroom (rare hopefully) then it won't need unsharing.
1354          *
1355          * Note. ddp-> becomes invalid at the realloc.
1356          */
1357         if (skb_headroom(skb) < 22) {
1358                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1359                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1360                 kfree_skb(skb);
1361                 if (!nskb)
1362                         goto out;
1363                 skb = nskb;
1364         } else
1365                 skb = skb_unshare(skb, GFP_ATOMIC);
1366
1367         /*
1368          * If the buffer didn't vanish into the lack of space bitbucket we can
1369          * send it.
1370          */
1371         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1372                 goto free_it;
1373 out:
1374         return;
1375 free_it:
1376         kfree_skb(skb);
1377 }
1378
1379 /**
1380  *      atalk_rcv - Receive a packet (in skb) from device dev
1381  *      @skb - packet received
1382  *      @dev - network device where the packet comes from
1383  *      @pt - packet type
1384  *
1385  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1386  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1387  *      is the DDP header, skb->len is the DDP length. The physical headers
1388  *      have been extracted. PPP should probably pass frames marked as for this
1389  *      layer.  [ie ARPHRD_ETHERTALK]
1390  */
1391 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1392                      struct packet_type *pt, struct net_device *orig_dev)
1393 {
1394         struct ddpehdr *ddp;
1395         struct sock *sock;
1396         struct atalk_iface *atif;
1397         struct sockaddr_at tosat;
1398         int origlen;
1399         __u16 len_hops;
1400
1401         /* Don't mangle buffer if shared */
1402         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1403                 goto out;
1404
1405         /* Size check and make sure header is contiguous */
1406         if (!pskb_may_pull(skb, sizeof(*ddp)))
1407                 goto freeit;
1408
1409         ddp = ddp_hdr(skb);
1410
1411         len_hops = ntohs(ddp->deh_len_hops);
1412
1413         /* Trim buffer in case of stray trailing data */
1414         origlen = skb->len;
1415         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1416
1417         /*
1418          * Size check to see if ddp->deh_len was crap
1419          * (Otherwise we'll detonate most spectacularly
1420          * in the middle of atalk_checksum() or recvmsg()).
1421          */
1422         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1423                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1424                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1425                 goto freeit;
1426         }
1427
1428         /*
1429          * Any checksums. Note we don't do htons() on this == is assumed to be
1430          * valid for net byte orders all over the networking code...
1431          */
1432         if (ddp->deh_sum &&
1433             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1434                 /* Not a valid AppleTalk frame - dustbin time */
1435                 goto freeit;
1436
1437         /* Check the packet is aimed at us */
1438         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1439                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1440         else
1441                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1442
1443         if (!atif) {
1444                 /* Not ours, so we route the packet via the correct
1445                  * AppleTalk iface
1446                  */
1447                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1448                 goto out;
1449         }
1450
1451         /* if IP over DDP is not selected this code will be optimized out */
1452         if (is_ip_over_ddp(skb))
1453                 return handle_ip_over_ddp(skb);
1454         /*
1455          * Which socket - atalk_search_socket() looks for a *full match*
1456          * of the <net, node, port> tuple.
1457          */
1458         tosat.sat_addr.s_net  = ddp->deh_dnet;
1459         tosat.sat_addr.s_node = ddp->deh_dnode;
1460         tosat.sat_port        = ddp->deh_dport;
1461
1462         sock = atalk_search_socket(&tosat, atif);
1463         if (!sock) /* But not one of our sockets */
1464                 goto freeit;
1465
1466         /* Queue packet (standard) */
1467         skb->sk = sock;
1468
1469         if (sock_queue_rcv_skb(sock, skb) < 0)
1470                 goto freeit;
1471 out:
1472         return 0;
1473 freeit:
1474         kfree_skb(skb);
1475         goto out;
1476 }
1477
1478 /*
1479  * Receive a LocalTalk frame. We make some demands on the caller here.
1480  * Caller must provide enough headroom on the packet to pull the short
1481  * header and append a long one.
1482  */
1483 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1484                      struct packet_type *pt, struct net_device *orig_dev)
1485 {
1486         /* Expand any short form frames */
1487         if (skb_mac_header(skb)[2] == 1) {
1488                 struct ddpehdr *ddp;
1489                 /* Find our address */
1490                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1491
1492                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1493                         goto freeit;
1494
1495                 /* Don't mangle buffer if shared */
1496                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1497                         return 0;
1498
1499                 /*
1500                  * The push leaves us with a ddephdr not an shdr, and
1501                  * handily the port bytes in the right place preset.
1502                  */
1503                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1504
1505                 /* Now fill in the long header */
1506
1507                 /*
1508                  * These two first. The mac overlays the new source/dest
1509                  * network information so we MUST copy these before
1510                  * we write the network numbers !
1511                  */
1512
1513                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1514                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1515
1516                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1517                 ddp->deh_snet  = ap->s_net;
1518                 ddp->deh_sum   = 0;             /* No checksum */
1519                 /*
1520                  * Not sure about this bit...
1521                  */
1522                 /* Non routable, so force a drop if we slip up later */
1523                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1524         }
1525         skb_reset_transport_header(skb);
1526
1527         return atalk_rcv(skb, dev, pt, orig_dev);
1528 freeit:
1529         kfree_skb(skb);
1530         return 0;
1531 }
1532
1533 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1534                          size_t len)
1535 {
1536         struct sock *sk = sock->sk;
1537         struct atalk_sock *at = at_sk(sk);
1538         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1539         int flags = msg->msg_flags;
1540         int loopback = 0;
1541         struct sockaddr_at local_satalk, gsat;
1542         struct sk_buff *skb;
1543         struct net_device *dev;
1544         struct ddpehdr *ddp;
1545         int size;
1546         struct atalk_route *rt;
1547         int err;
1548
1549         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1550                 return -EINVAL;
1551
1552         if (len > DDP_MAXSZ)
1553                 return -EMSGSIZE;
1554
1555         if (usat) {
1556                 if (sock_flag(sk, SOCK_ZAPPED))
1557                         if (atalk_autobind(sk) < 0)
1558                                 return -EBUSY;
1559
1560                 if (msg->msg_namelen < sizeof(*usat) ||
1561                     usat->sat_family != AF_APPLETALK)
1562                         return -EINVAL;
1563
1564                 /* netatalk doesn't implement this check */
1565                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1566                     !sock_flag(sk, SOCK_BROADCAST)) {
1567                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1568                                          "it will break before 2.2\n");
1569 #if 0
1570                         return -EPERM;
1571 #endif
1572                 }
1573         } else {
1574                 if (sk->sk_state != TCP_ESTABLISHED)
1575                         return -ENOTCONN;
1576                 usat = &local_satalk;
1577                 usat->sat_family      = AF_APPLETALK;
1578                 usat->sat_port        = at->dest_port;
1579                 usat->sat_addr.s_node = at->dest_node;
1580                 usat->sat_addr.s_net  = at->dest_net;
1581         }
1582
1583         /* Build a packet */
1584         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1585
1586         /* For headers */
1587         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1588
1589         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1590                 rt = atrtr_find(&usat->sat_addr);
1591         } else {
1592                 struct atalk_addr at_hint;
1593
1594                 at_hint.s_node = 0;
1595                 at_hint.s_net  = at->src_net;
1596
1597                 rt = atrtr_find(&at_hint);
1598         }
1599         if (!rt)
1600                 return -ENETUNREACH;
1601
1602         dev = rt->dev;
1603
1604         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1605                         sk, size, dev->name);
1606
1607         size += dev->hard_header_len;
1608         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1609         if (!skb)
1610                 return err;
1611
1612         skb->sk = sk;
1613         skb_reserve(skb, ddp_dl->header_length);
1614         skb_reserve(skb, dev->hard_header_len);
1615         skb->dev = dev;
1616
1617         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1618
1619         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1620         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1621         ddp->deh_dnet  = usat->sat_addr.s_net;
1622         ddp->deh_snet  = at->src_net;
1623         ddp->deh_dnode = usat->sat_addr.s_node;
1624         ddp->deh_snode = at->src_node;
1625         ddp->deh_dport = usat->sat_port;
1626         ddp->deh_sport = at->src_port;
1627
1628         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1629
1630         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1631         if (err) {
1632                 kfree_skb(skb);
1633                 return -EFAULT;
1634         }
1635
1636         if (sk->sk_no_check == 1)
1637                 ddp->deh_sum = 0;
1638         else
1639                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1640
1641         /*
1642          * Loopback broadcast packets to non gateway targets (ie routes
1643          * to group we are in)
1644          */
1645         if (ddp->deh_dnode == ATADDR_BCAST &&
1646             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1647                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1648
1649                 if (skb2) {
1650                         loopback = 1;
1651                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1652                         if (aarp_send_ddp(dev, skb2,
1653                                           &usat->sat_addr, NULL) == -1)
1654                                 kfree_skb(skb2);
1655                                 /* else queued/sent above in the aarp queue */
1656                 }
1657         }
1658
1659         if (dev->flags & IFF_LOOPBACK || loopback) {
1660                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1661                 /* loop back */
1662                 skb_orphan(skb);
1663                 if (ddp->deh_dnode == ATADDR_BCAST) {
1664                         struct atalk_addr at_lo;
1665
1666                         at_lo.s_node = 0;
1667                         at_lo.s_net  = 0;
1668
1669                         rt = atrtr_find(&at_lo);
1670                         if (!rt) {
1671                                 kfree_skb(skb);
1672                                 return -ENETUNREACH;
1673                         }
1674                         dev = rt->dev;
1675                         skb->dev = dev;
1676                 }
1677                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1678         } else {
1679                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1680                 if (rt->flags & RTF_GATEWAY) {
1681                     gsat.sat_addr = rt->gateway;
1682                     usat = &gsat;
1683                 }
1684
1685                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1686                         kfree_skb(skb);
1687                 /* else queued/sent above in the aarp queue */
1688         }
1689         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1690
1691         return len;
1692 }
1693
1694 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1695                          size_t size, int flags)
1696 {
1697         struct sock *sk = sock->sk;
1698         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1699         struct ddpehdr *ddp;
1700         int copied = 0;
1701         int offset = 0;
1702         int err = 0;
1703         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1704                                                 flags & MSG_DONTWAIT, &err);
1705         if (!skb)
1706                 return err;
1707
1708         /* FIXME: use skb->cb to be able to use shared skbs */
1709         ddp = ddp_hdr(skb);
1710         copied = ntohs(ddp->deh_len_hops) & 1023;
1711
1712         if (sk->sk_type != SOCK_RAW) {
1713                 offset = sizeof(*ddp);
1714                 copied -= offset;
1715         }
1716
1717         if (copied > size) {
1718                 copied = size;
1719                 msg->msg_flags |= MSG_TRUNC;
1720         }
1721         err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1722
1723         if (!err) {
1724                 if (sat) {
1725                         sat->sat_family      = AF_APPLETALK;
1726                         sat->sat_port        = ddp->deh_sport;
1727                         sat->sat_addr.s_node = ddp->deh_snode;
1728                         sat->sat_addr.s_net  = ddp->deh_snet;
1729                 }
1730                 msg->msg_namelen = sizeof(*sat);
1731         }
1732
1733         skb_free_datagram(sk, skb);     /* Free the datagram. */
1734         return err ? : copied;
1735 }
1736
1737
1738 /*
1739  * AppleTalk ioctl calls.
1740  */
1741 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1742 {
1743         int rc = -ENOIOCTLCMD;
1744         struct sock *sk = sock->sk;
1745         void __user *argp = (void __user *)arg;
1746
1747         switch (cmd) {
1748                 /* Protocol layer */
1749                 case TIOCOUTQ: {
1750                         long amount = sk->sk_sndbuf -
1751                                       atomic_read(&sk->sk_wmem_alloc);
1752
1753                         if (amount < 0)
1754                                 amount = 0;
1755                         rc = put_user(amount, (int __user *)argp);
1756                         break;
1757                 }
1758                 case TIOCINQ: {
1759                         /*
1760                          * These two are safe on a single CPU system as only
1761                          * user tasks fiddle here
1762                          */
1763                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1764                         long amount = 0;
1765
1766                         if (skb)
1767                                 amount = skb->len - sizeof(struct ddpehdr);
1768                         rc = put_user(amount, (int __user *)argp);
1769                         break;
1770                 }
1771                 case SIOCGSTAMP:
1772                         rc = sock_get_timestamp(sk, argp);
1773                         break;
1774                 case SIOCGSTAMPNS:
1775                         rc = sock_get_timestampns(sk, argp);
1776                         break;
1777                 /* Routing */
1778                 case SIOCADDRT:
1779                 case SIOCDELRT:
1780                         rc = -EPERM;
1781                         if (capable(CAP_NET_ADMIN))
1782                                 rc = atrtr_ioctl(cmd, argp);
1783                         break;
1784                 /* Interface */
1785                 case SIOCGIFADDR:
1786                 case SIOCSIFADDR:
1787                 case SIOCGIFBRDADDR:
1788                 case SIOCATALKDIFADDR:
1789                 case SIOCDIFADDR:
1790                 case SIOCSARP:          /* proxy AARP */
1791                 case SIOCDARP:          /* proxy AARP */
1792                         rtnl_lock();
1793                         rc = atif_ioctl(cmd, argp);
1794                         rtnl_unlock();
1795                         break;
1796         }
1797
1798         return rc;
1799 }
1800
1801
1802 #ifdef CONFIG_COMPAT
1803 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1804 {
1805         /*
1806          * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
1807          * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1808          * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
1809          * here so there is no generic SIOCPROTOPRIVATE translation in the
1810          * system.
1811          */
1812         return -ENOIOCTLCMD;
1813 }
1814 #endif
1815
1816
1817 static struct net_proto_family atalk_family_ops = {
1818         .family         = PF_APPLETALK,
1819         .create         = atalk_create,
1820         .owner          = THIS_MODULE,
1821 };
1822
1823 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1824         .family         = PF_APPLETALK,
1825         .owner          = THIS_MODULE,
1826         .release        = atalk_release,
1827         .bind           = atalk_bind,
1828         .connect        = atalk_connect,
1829         .socketpair     = sock_no_socketpair,
1830         .accept         = sock_no_accept,
1831         .getname        = atalk_getname,
1832         .poll           = datagram_poll,
1833         .ioctl          = atalk_ioctl,
1834 #ifdef CONFIG_COMPAT
1835         .compat_ioctl   = atalk_compat_ioctl,
1836 #endif
1837         .listen         = sock_no_listen,
1838         .shutdown       = sock_no_shutdown,
1839         .setsockopt     = sock_no_setsockopt,
1840         .getsockopt     = sock_no_getsockopt,
1841         .sendmsg        = atalk_sendmsg,
1842         .recvmsg        = atalk_recvmsg,
1843         .mmap           = sock_no_mmap,
1844         .sendpage       = sock_no_sendpage,
1845 };
1846
1847 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1848
1849 static struct notifier_block ddp_notifier = {
1850         .notifier_call  = ddp_device_event,
1851 };
1852
1853 static struct packet_type ltalk_packet_type = {
1854         .type           = __constant_htons(ETH_P_LOCALTALK),
1855         .func           = ltalk_rcv,
1856 };
1857
1858 static struct packet_type ppptalk_packet_type = {
1859         .type           = __constant_htons(ETH_P_PPPTALK),
1860         .func           = atalk_rcv,
1861 };
1862
1863 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1864
1865 /* Export symbols for use by drivers when AppleTalk is a module */
1866 EXPORT_SYMBOL(aarp_send_ddp);
1867 EXPORT_SYMBOL(atrtr_get_dev);
1868 EXPORT_SYMBOL(atalk_find_dev_addr);
1869
1870 static char atalk_err_snap[] __initdata =
1871         KERN_CRIT "Unable to register DDP with SNAP.\n";
1872
1873 /* Called by proto.c on kernel start up */
1874 static int __init atalk_init(void)
1875 {
1876         int rc = proto_register(&ddp_proto, 0);
1877
1878         if (rc != 0)
1879                 goto out;
1880
1881         (void)sock_register(&atalk_family_ops);
1882         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1883         if (!ddp_dl)
1884                 printk(atalk_err_snap);
1885
1886         dev_add_pack(&ltalk_packet_type);
1887         dev_add_pack(&ppptalk_packet_type);
1888
1889         register_netdevice_notifier(&ddp_notifier);
1890         aarp_proto_init();
1891         atalk_proc_init();
1892         atalk_register_sysctl();
1893 out:
1894         return rc;
1895 }
1896 module_init(atalk_init);
1897
1898 /*
1899  * No explicit module reference count manipulation is needed in the
1900  * protocol. Socket layer sets module reference count for us
1901  * and interfaces reference counting is done
1902  * by the network device layer.
1903  *
1904  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1905  * sockets be closed from user space.
1906  */
1907 static void __exit atalk_exit(void)
1908 {
1909 #ifdef CONFIG_SYSCTL
1910         atalk_unregister_sysctl();
1911 #endif /* CONFIG_SYSCTL */
1912         atalk_proc_exit();
1913         aarp_cleanup_module();  /* General aarp clean-up. */
1914         unregister_netdevice_notifier(&ddp_notifier);
1915         dev_remove_pack(&ltalk_packet_type);
1916         dev_remove_pack(&ppptalk_packet_type);
1917         unregister_snap_client(ddp_dl);
1918         sock_unregister(PF_APPLETALK);
1919         proto_unregister(&ddp_proto);
1920 }
1921 module_exit(atalk_exit);
1922
1923 MODULE_LICENSE("GPL");
1924 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1925 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1926 MODULE_ALIAS_NETPROTO(PF_APPLETALK);