1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * DDP: An implementation of the AppleTalk DDP protocol for
4 * Ethernet 'ELAP'.
5 *
6 * Alan Cox <alan@lxorguk.ukuu.org.uk>
7 *
8 * With more than a little assistance from
9 *
10 * Wesley Craig <netatalk@umich.edu>
11 *
12 * Fixes:
13 * Neil Horman : Added missing device ioctls
14 * Michael Callahan : Made routing work
15 * Wesley Craig : Fix probing to listen to a
16 * passed node id.
17 * Alan Cox : Added send/recvmsg support
18 * Alan Cox : Moved at. to protinfo in
19 * socket.
20 * Alan Cox : Added firewall hooks.
21 * Alan Cox : Supports new ARPHRD_LOOPBACK
22 * Christer Weinigel : Routing and /proc fixes.
23 * Bradford Johnson : LocalTalk.
24 * Tom Dyas : Module support.
25 * Alan Cox : Hooks for PPP (based on the
26 * LocalTalk hook).
27 * Alan Cox : Posix bits
28 * Alan Cox/Mike Freeman : Possible fix to NBP problems
29 * Bradford Johnson : IP-over-DDP (experimental)
30 * Jay Schulist : Moved IP-over-DDP to its own
31 * driver file. (ipddp.c & ipddp.h)
32 * Jay Schulist : Made work as module with
33 * AppleTalk drivers, cleaned it.
34 * Rob Newberry : Added proxy AARP and AARP
35 * procfs, moved probing to AARP
36 * module.
37 * Adrian Sun/
38 * Michael Zuelsdorff : fix for net.0 packets. don't
39 * allow illegal ether/tokentalk
40 * port assignment. we lose a
41 * valid localtalk port as a
42 * result.
43 * Arnaldo C. de Melo : Cleanup, in preparation for
44 * shared skb support 8)
45 * Arnaldo C. de Melo : Move proc stuff to atalk_proc.c,
46 * use seq_file
47 */
48
49 #include <linux/capability.h>
50 #include <linux/module.h>
51 #include <linux/if_arp.h>
52 #include <linux/termios.h> /* For TIOCOUTQ/INQ */
53 #include <linux/compat.h>
54 #include <linux/slab.h>
55 #include <net/datalink.h>
56 #include <net/psnap.h>
57 #include <net/sock.h>
58 #include <net/tcp_states.h>
59 #include <net/route.h>
60 #include <net/compat.h>
61 #include <linux/atalk.h>
62 #include <linux/highmem.h>
63
64 struct datalink_proto *ddp_dl, *aarp_dl;
65 static const struct proto_ops atalk_dgram_ops;
66
67 /**************************************************************************\
68 * *
69 * Handlers for the socket list. *
70 * *
71 \**************************************************************************/
72
73 HLIST_HEAD(atalk_sockets);
74 DEFINE_RWLOCK(atalk_sockets_lock);
75
__atalk_insert_socket(struct sock * sk)76 static inline void __atalk_insert_socket(struct sock *sk)
77 {
78 sk_add_node(sk, &atalk_sockets);
79 }
80
atalk_remove_socket(struct sock * sk)81 static inline void atalk_remove_socket(struct sock *sk)
82 {
83 write_lock_bh(&atalk_sockets_lock);
84 sk_del_node_init(sk);
85 write_unlock_bh(&atalk_sockets_lock);
86 }
87
atalk_search_socket(struct sockaddr_at * to,struct atalk_iface * atif)88 static struct sock *atalk_search_socket(struct sockaddr_at *to,
89 struct atalk_iface *atif)
90 {
91 struct sock *def_socket = NULL;
92 struct sock *s;
93
94 read_lock_bh(&atalk_sockets_lock);
95 sk_for_each(s, &atalk_sockets) {
96 struct atalk_sock *at = at_sk(s);
97
98 if (to->sat_port != at->src_port)
99 continue;
100
101 if (to->sat_addr.s_net == ATADDR_ANYNET &&
102 to->sat_addr.s_node == ATADDR_BCAST) {
103 if (atif->address.s_node == at->src_node &&
104 atif->address.s_net == at->src_net) {
105 /* This socket's address matches the address of the interface
106 * that received the packet -- use it
107 */
108 goto found;
109 }
110
111 /* Continue searching for a socket matching the interface address,
112 * but use this socket by default if no other one is found
113 */
114 def_socket = s;
115 }
116
117 if (to->sat_addr.s_net == at->src_net &&
118 (to->sat_addr.s_node == at->src_node ||
119 to->sat_addr.s_node == ATADDR_BCAST ||
120 to->sat_addr.s_node == ATADDR_ANYNODE))
121 goto found;
122
123 /* XXXX.0 -- we got a request for this router. make sure
124 * that the node is appropriately set. */
125 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
126 to->sat_addr.s_net != ATADDR_ANYNET &&
127 atif->address.s_node == at->src_node) {
128 to->sat_addr.s_node = atif->address.s_node;
129 goto found;
130 }
131 }
132 s = def_socket;
133 found:
134 read_unlock_bh(&atalk_sockets_lock);
135 return s;
136 }
137
138 /**
139 * atalk_find_or_insert_socket - Try to find a socket matching ADDR
140 * @sk: socket to insert in the list if it is not there already
141 * @sat: address to search for
142 *
143 * Try to find a socket matching ADDR in the socket list, if found then return
144 * it. If not, insert SK into the socket list.
145 *
146 * This entire operation must execute atomically.
147 */
atalk_find_or_insert_socket(struct sock * sk,struct sockaddr_at * sat)148 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
149 struct sockaddr_at *sat)
150 {
151 struct sock *s;
152 struct atalk_sock *at;
153
154 write_lock_bh(&atalk_sockets_lock);
155 sk_for_each(s, &atalk_sockets) {
156 at = at_sk(s);
157
158 if (at->src_net == sat->sat_addr.s_net &&
159 at->src_node == sat->sat_addr.s_node &&
160 at->src_port == sat->sat_port)
161 goto found;
162 }
163 s = NULL;
164 __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
165 found:
166 write_unlock_bh(&atalk_sockets_lock);
167 return s;
168 }
169
atalk_destroy_timer(struct timer_list * t)170 static void atalk_destroy_timer(struct timer_list *t)
171 {
172 struct sock *sk = from_timer(sk, t, sk_timer);
173
174 if (sk_has_allocations(sk)) {
175 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
176 add_timer(&sk->sk_timer);
177 } else
178 sock_put(sk);
179 }
180
atalk_destroy_socket(struct sock * sk)181 static inline void atalk_destroy_socket(struct sock *sk)
182 {
183 atalk_remove_socket(sk);
184 skb_queue_purge(&sk->sk_receive_queue);
185
186 if (sk_has_allocations(sk)) {
187 timer_setup(&sk->sk_timer, atalk_destroy_timer, 0);
188 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
189 add_timer(&sk->sk_timer);
190 } else
191 sock_put(sk);
192 }
193
194 /**************************************************************************\
195 * *
196 * Routing tables for the AppleTalk socket layer. *
197 * *
198 \**************************************************************************/
199
200 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
201 struct atalk_route *atalk_routes;
202 DEFINE_RWLOCK(atalk_routes_lock);
203
204 struct atalk_iface *atalk_interfaces;
205 DEFINE_RWLOCK(atalk_interfaces_lock);
206
207 /* For probing devices or in a routerless network */
208 struct atalk_route atrtr_default;
209
210 /* AppleTalk interface control */
211 /*
212 * Drop a device. Doesn't drop any of its routes - that is the caller's
213 * problem. Called when we down the interface or delete the address.
214 */
atif_drop_device(struct net_device * dev)215 static void atif_drop_device(struct net_device *dev)
216 {
217 struct atalk_iface **iface = &atalk_interfaces;
218 struct atalk_iface *tmp;
219
220 write_lock_bh(&atalk_interfaces_lock);
221 while ((tmp = *iface) != NULL) {
222 if (tmp->dev == dev) {
223 *iface = tmp->next;
224 dev_put(dev);
225 kfree(tmp);
226 dev->atalk_ptr = NULL;
227 } else
228 iface = &tmp->next;
229 }
230 write_unlock_bh(&atalk_interfaces_lock);
231 }
232
atif_add_device(struct net_device * dev,struct atalk_addr * sa)233 static struct atalk_iface *atif_add_device(struct net_device *dev,
234 struct atalk_addr *sa)
235 {
236 struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
237
238 if (!iface)
239 goto out;
240
241 dev_hold(dev);
242 iface->dev = dev;
243 dev->atalk_ptr = iface;
244 iface->address = *sa;
245 iface->status = 0;
246
247 write_lock_bh(&atalk_interfaces_lock);
248 iface->next = atalk_interfaces;
249 atalk_interfaces = iface;
250 write_unlock_bh(&atalk_interfaces_lock);
251 out:
252 return iface;
253 }
254
255 /* Perform phase 2 AARP probing on our tentative address */
atif_probe_device(struct atalk_iface * atif)256 static int atif_probe_device(struct atalk_iface *atif)
257 {
258 int netrange = ntohs(atif->nets.nr_lastnet) -
259 ntohs(atif->nets.nr_firstnet) + 1;
260 int probe_net = ntohs(atif->address.s_net);
261 int probe_node = atif->address.s_node;
262 int netct, nodect;
263
264 /* Offset the network we start probing with */
265 if (probe_net == ATADDR_ANYNET) {
266 probe_net = ntohs(atif->nets.nr_firstnet);
267 if (netrange)
268 probe_net += jiffies % netrange;
269 }
270 if (probe_node == ATADDR_ANYNODE)
271 probe_node = jiffies & 0xFF;
272
273 /* Scan the networks */
274 atif->status |= ATIF_PROBE;
275 for (netct = 0; netct <= netrange; netct++) {
276 /* Sweep the available nodes from a given start */
277 atif->address.s_net = htons(probe_net);
278 for (nodect = 0; nodect < 256; nodect++) {
279 atif->address.s_node = (nodect + probe_node) & 0xFF;
280 if (atif->address.s_node > 0 &&
281 atif->address.s_node < 254) {
282 /* Probe a proposed address */
283 aarp_probe_network(atif);
284
285 if (!(atif->status & ATIF_PROBE_FAIL)) {
286 atif->status &= ~ATIF_PROBE;
287 return 0;
288 }
289 }
290 atif->status &= ~ATIF_PROBE_FAIL;
291 }
292 probe_net++;
293 if (probe_net > ntohs(atif->nets.nr_lastnet))
294 probe_net = ntohs(atif->nets.nr_firstnet);
295 }
296 atif->status &= ~ATIF_PROBE;
297
298 return -EADDRINUSE; /* Network is full... */
299 }
300
301
302 /* Perform AARP probing for a proxy address */
atif_proxy_probe_device(struct atalk_iface * atif,struct atalk_addr * proxy_addr)303 static int atif_proxy_probe_device(struct atalk_iface *atif,
304 struct atalk_addr *proxy_addr)
305 {
306 int netrange = ntohs(atif->nets.nr_lastnet) -
307 ntohs(atif->nets.nr_firstnet) + 1;
308 /* we probe the interface's network */
309 int probe_net = ntohs(atif->address.s_net);
310 int probe_node = ATADDR_ANYNODE; /* we'll take anything */
311 int netct, nodect;
312
313 /* Offset the network we start probing with */
314 if (probe_net == ATADDR_ANYNET) {
315 probe_net = ntohs(atif->nets.nr_firstnet);
316 if (netrange)
317 probe_net += jiffies % netrange;
318 }
319
320 if (probe_node == ATADDR_ANYNODE)
321 probe_node = jiffies & 0xFF;
322
323 /* Scan the networks */
324 for (netct = 0; netct <= netrange; netct++) {
325 /* Sweep the available nodes from a given start */
326 proxy_addr->s_net = htons(probe_net);
327 for (nodect = 0; nodect < 256; nodect++) {
328 proxy_addr->s_node = (nodect + probe_node) & 0xFF;
329 if (proxy_addr->s_node > 0 &&
330 proxy_addr->s_node < 254) {
331 /* Tell AARP to probe a proposed address */
332 int ret = aarp_proxy_probe_network(atif,
333 proxy_addr);
334
335 if (ret != -EADDRINUSE)
336 return ret;
337 }
338 }
339 probe_net++;
340 if (probe_net > ntohs(atif->nets.nr_lastnet))
341 probe_net = ntohs(atif->nets.nr_firstnet);
342 }
343
344 return -EADDRINUSE; /* Network is full... */
345 }
346
347
atalk_find_dev_addr(struct net_device * dev)348 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
349 {
350 struct atalk_iface *iface = dev->atalk_ptr;
351 return iface ? &iface->address : NULL;
352 }
353
atalk_find_primary(void)354 static struct atalk_addr *atalk_find_primary(void)
355 {
356 struct atalk_iface *fiface = NULL;
357 struct atalk_addr *retval;
358 struct atalk_iface *iface;
359
360 /*
361 * Return a point-to-point interface only if
362 * there is no non-ptp interface available.
363 */
364 read_lock_bh(&atalk_interfaces_lock);
365 for (iface = atalk_interfaces; iface; iface = iface->next) {
366 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
367 fiface = iface;
368 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
369 retval = &iface->address;
370 goto out;
371 }
372 }
373
374 if (fiface)
375 retval = &fiface->address;
376 else if (atalk_interfaces)
377 retval = &atalk_interfaces->address;
378 else
379 retval = NULL;
380 out:
381 read_unlock_bh(&atalk_interfaces_lock);
382 return retval;
383 }
384
385 /*
386 * Find a match for 'any network' - ie any of our interfaces with that
387 * node number will do just nicely.
388 */
atalk_find_anynet(int node,struct net_device * dev)389 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
390 {
391 struct atalk_iface *iface = dev->atalk_ptr;
392
393 if (!iface || iface->status & ATIF_PROBE)
394 goto out_err;
395
396 if (node != ATADDR_BCAST &&
397 iface->address.s_node != node &&
398 node != ATADDR_ANYNODE)
399 goto out_err;
400 out:
401 return iface;
402 out_err:
403 iface = NULL;
404 goto out;
405 }
406
407 /* Find a match for a specific network:node pair */
atalk_find_interface(__be16 net,int node)408 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
409 {
410 struct atalk_iface *iface;
411
412 read_lock_bh(&atalk_interfaces_lock);
413 for (iface = atalk_interfaces; iface; iface = iface->next) {
414 if ((node == ATADDR_BCAST ||
415 node == ATADDR_ANYNODE ||
416 iface->address.s_node == node) &&
417 iface->address.s_net == net &&
418 !(iface->status & ATIF_PROBE))
419 break;
420
421 /* XXXX.0 -- net.0 returns the iface associated with net */
422 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
423 ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
424 ntohs(net) <= ntohs(iface->nets.nr_lastnet))
425 break;
426 }
427 read_unlock_bh(&atalk_interfaces_lock);
428 return iface;
429 }
430
431
432 /*
433 * Find a route for an AppleTalk packet. This ought to get cached in
434 * the socket (later on...). We know about host routes and the fact
435 * that a route must be direct to broadcast.
436 */
atrtr_find(struct atalk_addr * target)437 static struct atalk_route *atrtr_find(struct atalk_addr *target)
438 {
439 /*
440 * we must search through all routes unless we find a
441 * host route, because some host routes might overlap
442 * network routes
443 */
444 struct atalk_route *net_route = NULL;
445 struct atalk_route *r;
446
447 read_lock_bh(&atalk_routes_lock);
448 for (r = atalk_routes; r; r = r->next) {
449 if (!(r->flags & RTF_UP))
450 continue;
451
452 if (r->target.s_net == target->s_net) {
453 if (r->flags & RTF_HOST) {
454 /*
455 * if this host route is for the target,
456 * the we're done
457 */
458 if (r->target.s_node == target->s_node)
459 goto out;
460 } else
461 /*
462 * this route will work if there isn't a
463 * direct host route, so cache it
464 */
465 net_route = r;
466 }
467 }
468
469 /*
470 * if we found a network route but not a direct host
471 * route, then return it
472 */
473 if (net_route)
474 r = net_route;
475 else if (atrtr_default.dev)
476 r = &atrtr_default;
477 else /* No route can be found */
478 r = NULL;
479 out:
480 read_unlock_bh(&atalk_routes_lock);
481 return r;
482 }
483
484
485 /*
486 * Given an AppleTalk network, find the device to use. This can be
487 * a simple lookup.
488 */
atrtr_get_dev(struct atalk_addr * sa)489 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
490 {
491 struct atalk_route *atr = atrtr_find(sa);
492 return atr ? atr->dev : NULL;
493 }
494
495 /* Set up a default router */
atrtr_set_default(struct net_device * dev)496 static void atrtr_set_default(struct net_device *dev)
497 {
498 atrtr_default.dev = dev;
499 atrtr_default.flags = RTF_UP;
500 atrtr_default.gateway.s_net = htons(0);
501 atrtr_default.gateway.s_node = 0;
502 }
503
504 /*
505 * Add a router. Basically make sure it looks valid and stuff the
506 * entry in the list. While it uses netranges we always set them to one
507 * entry to work like netatalk.
508 */
atrtr_create(struct rtentry * r,struct net_device * devhint)509 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
510 {
511 struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
512 struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
513 struct atalk_route *rt;
514 struct atalk_iface *iface, *riface;
515 int retval = -EINVAL;
516
517 /*
518 * Fixme: Raise/Lower a routing change semaphore for these
519 * operations.
520 */
521
522 /* Validate the request */
523 if (ta->sat_family != AF_APPLETALK ||
524 (!devhint && ga->sat_family != AF_APPLETALK))
525 goto out;
526
527 /* Now walk the routing table and make our decisions */
528 write_lock_bh(&atalk_routes_lock);
529 for (rt = atalk_routes; rt; rt = rt->next) {
530 if (r->rt_flags != rt->flags)
531 continue;
532
533 if (ta->sat_addr.s_net == rt->target.s_net) {
534 if (!(rt->flags & RTF_HOST))
535 break;
536 if (ta->sat_addr.s_node == rt->target.s_node)
537 break;
538 }
539 }
540
541 if (!devhint) {
542 riface = NULL;
543
544 read_lock_bh(&atalk_interfaces_lock);
545 for (iface = atalk_interfaces; iface; iface = iface->next) {
546 if (!riface &&
547 ntohs(ga->sat_addr.s_net) >=
548 ntohs(iface->nets.nr_firstnet) &&
549 ntohs(ga->sat_addr.s_net) <=
550 ntohs(iface->nets.nr_lastnet))
551 riface = iface;
552
553 if (ga->sat_addr.s_net == iface->address.s_net &&
554 ga->sat_addr.s_node == iface->address.s_node)
555 riface = iface;
556 }
557 read_unlock_bh(&atalk_interfaces_lock);
558
559 retval = -ENETUNREACH;
560 if (!riface)
561 goto out_unlock;
562
563 devhint = riface->dev;
564 }
565
566 if (!rt) {
567 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
568
569 retval = -ENOBUFS;
570 if (!rt)
571 goto out_unlock;
572
573 rt->next = atalk_routes;
574 atalk_routes = rt;
575 }
576
577 /* Fill in the routing entry */
578 rt->target = ta->sat_addr;
579 dev_hold(devhint);
580 rt->dev = devhint;
581 rt->flags = r->rt_flags;
582 rt->gateway = ga->sat_addr;
583
584 retval = 0;
585 out_unlock:
586 write_unlock_bh(&atalk_routes_lock);
587 out:
588 return retval;
589 }
590
591 /* Delete a route. Find it and discard it */
atrtr_delete(struct atalk_addr * addr)592 static int atrtr_delete(struct atalk_addr *addr)
593 {
594 struct atalk_route **r = &atalk_routes;
595 int retval = 0;
596 struct atalk_route *tmp;
597
598 write_lock_bh(&atalk_routes_lock);
599 while ((tmp = *r) != NULL) {
600 if (tmp->target.s_net == addr->s_net &&
601 (!(tmp->flags&RTF_GATEWAY) ||
602 tmp->target.s_node == addr->s_node)) {
603 *r = tmp->next;
604 dev_put(tmp->dev);
605 kfree(tmp);
606 goto out;
607 }
608 r = &tmp->next;
609 }
610 retval = -ENOENT;
611 out:
612 write_unlock_bh(&atalk_routes_lock);
613 return retval;
614 }
615
616 /*
617 * Called when a device is downed. Just throw away any routes
618 * via it.
619 */
atrtr_device_down(struct net_device * dev)620 static void atrtr_device_down(struct net_device *dev)
621 {
622 struct atalk_route **r = &atalk_routes;
623 struct atalk_route *tmp;
624
625 write_lock_bh(&atalk_routes_lock);
626 while ((tmp = *r) != NULL) {
627 if (tmp->dev == dev) {
628 *r = tmp->next;
629 dev_put(dev);
630 kfree(tmp);
631 } else
632 r = &tmp->next;
633 }
634 write_unlock_bh(&atalk_routes_lock);
635
636 if (atrtr_default.dev == dev)
637 atrtr_set_default(NULL);
638 }
639
640 /* Actually down the interface */
atalk_dev_down(struct net_device * dev)641 static inline void atalk_dev_down(struct net_device *dev)
642 {
643 atrtr_device_down(dev); /* Remove all routes for the device */
644 aarp_device_down(dev); /* Remove AARP entries for the device */
645 atif_drop_device(dev); /* Remove the device */
646 }
647
648 /*
649 * A device event has occurred. Watch for devices going down and
650 * delete our use of them (iface and route).
651 */
ddp_device_event(struct notifier_block * this,unsigned long event,void * ptr)652 static int ddp_device_event(struct notifier_block *this, unsigned long event,
653 void *ptr)
654 {
655 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
656
657 if (!net_eq(dev_net(dev), &init_net))
658 return NOTIFY_DONE;
659
660 if (event == NETDEV_DOWN)
661 /* Discard any use of this */
662 atalk_dev_down(dev);
663
664 return NOTIFY_DONE;
665 }
666
667 /* ioctl calls. Shouldn't even need touching */
668 /* Device configuration ioctl calls */
atif_ioctl(int cmd,void __user * arg)669 static int atif_ioctl(int cmd, void __user *arg)
670 {
671 static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
672 struct ifreq atreq;
673 struct atalk_netrange *nr;
674 struct sockaddr_at *sa;
675 struct net_device *dev;
676 struct atalk_iface *atif;
677 int ct;
678 int limit;
679 struct rtentry rtdef;
680 int add_route;
681
682 if (get_user_ifreq(&atreq, NULL, arg))
683 return -EFAULT;
684
685 dev = __dev_get_by_name(&init_net, atreq.ifr_name);
686 if (!dev)
687 return -ENODEV;
688
689 sa = (struct sockaddr_at *)&atreq.ifr_addr;
690 atif = atalk_find_dev(dev);
691
692 switch (cmd) {
693 case SIOCSIFADDR:
694 if (!capable(CAP_NET_ADMIN))
695 return -EPERM;
696 if (sa->sat_family != AF_APPLETALK)
697 return -EINVAL;
698 if (dev->type != ARPHRD_ETHER &&
699 dev->type != ARPHRD_LOOPBACK &&
700 dev->type != ARPHRD_LOCALTLK &&
701 dev->type != ARPHRD_PPP)
702 return -EPROTONOSUPPORT;
703
704 nr = (struct atalk_netrange *)&sa->sat_zero[0];
705 add_route = 1;
706
707 /*
708 * if this is a point-to-point iface, and we already
709 * have an iface for this AppleTalk address, then we
710 * should not add a route
711 */
712 if ((dev->flags & IFF_POINTOPOINT) &&
713 atalk_find_interface(sa->sat_addr.s_net,
714 sa->sat_addr.s_node)) {
715 printk(KERN_DEBUG "AppleTalk: point-to-point "
716 "interface added with "
717 "existing address\n");
718 add_route = 0;
719 }
720
721 /*
722 * Phase 1 is fine on LocalTalk but we don't do
723 * EtherTalk phase 1. Anyone wanting to add it, go ahead.
724 */
725 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
726 return -EPROTONOSUPPORT;
727 if (sa->sat_addr.s_node == ATADDR_BCAST ||
728 sa->sat_addr.s_node == 254)
729 return -EINVAL;
730 if (atif) {
731 /* Already setting address */
732 if (atif->status & ATIF_PROBE)
733 return -EBUSY;
734
735 atif->address.s_net = sa->sat_addr.s_net;
736 atif->address.s_node = sa->sat_addr.s_node;
737 atrtr_device_down(dev); /* Flush old routes */
738 } else {
739 atif = atif_add_device(dev, &sa->sat_addr);
740 if (!atif)
741 return -ENOMEM;
742 }
743 atif->nets = *nr;
744
745 /*
746 * Check if the chosen address is used. If so we
747 * error and atalkd will try another.
748 */
749
750 if (!(dev->flags & IFF_LOOPBACK) &&
751 !(dev->flags & IFF_POINTOPOINT) &&
752 atif_probe_device(atif) < 0) {
753 atif_drop_device(dev);
754 return -EADDRINUSE;
755 }
756
757 /* Hey it worked - add the direct routes */
758 sa = (struct sockaddr_at *)&rtdef.rt_gateway;
759 sa->sat_family = AF_APPLETALK;
760 sa->sat_addr.s_net = atif->address.s_net;
761 sa->sat_addr.s_node = atif->address.s_node;
762 sa = (struct sockaddr_at *)&rtdef.rt_dst;
763 rtdef.rt_flags = RTF_UP;
764 sa->sat_family = AF_APPLETALK;
765 sa->sat_addr.s_node = ATADDR_ANYNODE;
766 if (dev->flags & IFF_LOOPBACK ||
767 dev->flags & IFF_POINTOPOINT)
768 rtdef.rt_flags |= RTF_HOST;
769
770 /* Routerless initial state */
771 if (nr->nr_firstnet == htons(0) &&
772 nr->nr_lastnet == htons(0xFFFE)) {
773 sa->sat_addr.s_net = atif->address.s_net;
774 atrtr_create(&rtdef, dev);
775 atrtr_set_default(dev);
776 } else {
777 limit = ntohs(nr->nr_lastnet);
778 if (limit - ntohs(nr->nr_firstnet) > 4096) {
779 printk(KERN_WARNING "Too many routes/"
780 "iface.\n");
781 return -EINVAL;
782 }
783 if (add_route)
784 for (ct = ntohs(nr->nr_firstnet);
785 ct <= limit; ct++) {
786 sa->sat_addr.s_net = htons(ct);
787 atrtr_create(&rtdef, dev);
788 }
789 }
790 dev_mc_add_global(dev, aarp_mcast);
791 return 0;
792
793 case SIOCGIFADDR:
794 if (!atif)
795 return -EADDRNOTAVAIL;
796
797 sa->sat_family = AF_APPLETALK;
798 sa->sat_addr = atif->address;
799 break;
800
801 case SIOCGIFBRDADDR:
802 if (!atif)
803 return -EADDRNOTAVAIL;
804
805 sa->sat_family = AF_APPLETALK;
806 sa->sat_addr.s_net = atif->address.s_net;
807 sa->sat_addr.s_node = ATADDR_BCAST;
808 break;
809
810 case SIOCATALKDIFADDR:
811 case SIOCDIFADDR:
812 if (!capable(CAP_NET_ADMIN))
813 return -EPERM;
814 if (sa->sat_family != AF_APPLETALK)
815 return -EINVAL;
816 atalk_dev_down(dev);
817 break;
818
819 case SIOCSARP:
820 if (!capable(CAP_NET_ADMIN))
821 return -EPERM;
822 if (sa->sat_family != AF_APPLETALK)
823 return -EINVAL;
824 /*
825 * for now, we only support proxy AARP on ELAP;
826 * we should be able to do it for LocalTalk, too.
827 */
828 if (dev->type != ARPHRD_ETHER)
829 return -EPROTONOSUPPORT;
830
831 /*
832 * atif points to the current interface on this network;
833 * we aren't concerned about its current status (at
834 * least for now), but it has all the settings about
835 * the network we're going to probe. Consequently, it
836 * must exist.
837 */
838 if (!atif)
839 return -EADDRNOTAVAIL;
840
841 nr = (struct atalk_netrange *)&(atif->nets);
842 /*
843 * Phase 1 is fine on Localtalk but we don't do
844 * Ethertalk phase 1. Anyone wanting to add it, go ahead.
845 */
846 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
847 return -EPROTONOSUPPORT;
848
849 if (sa->sat_addr.s_node == ATADDR_BCAST ||
850 sa->sat_addr.s_node == 254)
851 return -EINVAL;
852
853 /*
854 * Check if the chosen address is used. If so we
855 * error and ATCP will try another.
856 */
857 if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
858 return -EADDRINUSE;
859
860 /*
861 * We now have an address on the local network, and
862 * the AARP code will defend it for us until we take it
863 * down. We don't set up any routes right now, because
864 * ATCP will install them manually via SIOCADDRT.
865 */
866 break;
867
868 case SIOCDARP:
869 if (!capable(CAP_NET_ADMIN))
870 return -EPERM;
871 if (sa->sat_family != AF_APPLETALK)
872 return -EINVAL;
873 if (!atif)
874 return -EADDRNOTAVAIL;
875
876 /* give to aarp module to remove proxy entry */
877 aarp_proxy_remove(atif->dev, &(sa->sat_addr));
878 return 0;
879 }
880
881 return put_user_ifreq(&atreq, arg);
882 }
883
atrtr_ioctl_addrt(struct rtentry * rt)884 static int atrtr_ioctl_addrt(struct rtentry *rt)
885 {
886 struct net_device *dev = NULL;
887
888 if (rt->rt_dev) {
889 char name[IFNAMSIZ];
890
891 if (copy_from_user(name, rt->rt_dev, IFNAMSIZ-1))
892 return -EFAULT;
893 name[IFNAMSIZ-1] = '\0';
894
895 dev = __dev_get_by_name(&init_net, name);
896 if (!dev)
897 return -ENODEV;
898 }
899 return atrtr_create(rt, dev);
900 }
901
902 /* Routing ioctl() calls */
atrtr_ioctl(unsigned int cmd,void __user * arg)903 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
904 {
905 struct rtentry rt;
906
907 if (copy_from_user(&rt, arg, sizeof(rt)))
908 return -EFAULT;
909
910 switch (cmd) {
911 case SIOCDELRT:
912 if (rt.rt_dst.sa_family != AF_APPLETALK)
913 return -EINVAL;
914 return atrtr_delete(&((struct sockaddr_at *)
915 &rt.rt_dst)->sat_addr);
916
917 case SIOCADDRT:
918 return atrtr_ioctl_addrt(&rt);
919 }
920 return -EINVAL;
921 }
922
923 /**************************************************************************\
924 * *
925 * Handling for system calls applied via the various interfaces to an *
926 * AppleTalk socket object. *
927 * *
928 \**************************************************************************/
929
930 /*
931 * Checksum: This is 'optional'. It's quite likely also a good
932 * candidate for assembler hackery 8)
933 */
atalk_sum_partial(const unsigned char * data,int len,unsigned long sum)934 static unsigned long atalk_sum_partial(const unsigned char *data,
935 int len, unsigned long sum)
936 {
937 /* This ought to be unwrapped neatly. I'll trust gcc for now */
938 while (len--) {
939 sum += *data++;
940 sum = rol16(sum, 1);
941 }
942 return sum;
943 }
944
945 /* Checksum skb data -- similar to skb_checksum */
atalk_sum_skb(const struct sk_buff * skb,int offset,int len,unsigned long sum)946 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
947 int len, unsigned long sum)
948 {
949 int start = skb_headlen(skb);
950 struct sk_buff *frag_iter;
951 int i, copy;
952
953 /* checksum stuff in header space */
954 if ((copy = start - offset) > 0) {
955 if (copy > len)
956 copy = len;
957 sum = atalk_sum_partial(skb->data + offset, copy, sum);
958 if ((len -= copy) == 0)
959 return sum;
960
961 offset += copy;
962 }
963
964 /* checksum stuff in frags */
965 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
966 int end;
967 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
968 WARN_ON(start > offset + len);
969
970 end = start + skb_frag_size(frag);
971 if ((copy = end - offset) > 0) {
972 u8 *vaddr;
973
974 if (copy > len)
975 copy = len;
976 vaddr = kmap_atomic(skb_frag_page(frag));
977 sum = atalk_sum_partial(vaddr + skb_frag_off(frag) +
978 offset - start, copy, sum);
979 kunmap_atomic(vaddr);
980
981 if (!(len -= copy))
982 return sum;
983 offset += copy;
984 }
985 start = end;
986 }
987
988 skb_walk_frags(skb, frag_iter) {
989 int end;
990
991 WARN_ON(start > offset + len);
992
993 end = start + frag_iter->len;
994 if ((copy = end - offset) > 0) {
995 if (copy > len)
996 copy = len;
997 sum = atalk_sum_skb(frag_iter, offset - start,
998 copy, sum);
999 if ((len -= copy) == 0)
1000 return sum;
1001 offset += copy;
1002 }
1003 start = end;
1004 }
1005
1006 BUG_ON(len > 0);
1007
1008 return sum;
1009 }
1010
atalk_checksum(const struct sk_buff * skb,int len)1011 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1012 {
1013 unsigned long sum;
1014
1015 /* skip header 4 bytes */
1016 sum = atalk_sum_skb(skb, 4, len-4, 0);
1017
1018 /* Use 0xFFFF for 0. 0 itself means none */
1019 return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1020 }
1021
1022 static struct proto ddp_proto = {
1023 .name = "DDP",
1024 .owner = THIS_MODULE,
1025 .obj_size = sizeof(struct atalk_sock),
1026 };
1027
1028 /*
1029 * Create a socket. Initialise the socket, blank the addresses
1030 * set the state.
1031 */
atalk_create(struct net * net,struct socket * sock,int protocol,int kern)1032 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1033 int kern)
1034 {
1035 struct sock *sk;
1036 int rc = -ESOCKTNOSUPPORT;
1037
1038 if (!net_eq(net, &init_net))
1039 return -EAFNOSUPPORT;
1040
1041 /*
1042 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1043 * and gives you the full ELAP frame. Should be handy for CAP 8)
1044 */
1045 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1046 goto out;
1047
1048 rc = -EPERM;
1049 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1050 goto out;
1051
1052 rc = -ENOMEM;
1053 sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, kern);
1054 if (!sk)
1055 goto out;
1056 rc = 0;
1057 sock->ops = &atalk_dgram_ops;
1058 sock_init_data(sock, sk);
1059
1060 /* Checksums on by default */
1061 sock_set_flag(sk, SOCK_ZAPPED);
1062 out:
1063 return rc;
1064 }
1065
1066 /* Free a socket. No work needed */
atalk_release(struct socket * sock)1067 static int atalk_release(struct socket *sock)
1068 {
1069 struct sock *sk = sock->sk;
1070
1071 if (sk) {
1072 sock_hold(sk);
1073 lock_sock(sk);
1074
1075 sock_orphan(sk);
1076 sock->sk = NULL;
1077 atalk_destroy_socket(sk);
1078
1079 release_sock(sk);
1080 sock_put(sk);
1081 }
1082 return 0;
1083 }
1084
1085 /**
1086 * atalk_pick_and_bind_port - Pick a source port when one is not given
1087 * @sk: socket to insert into the tables
1088 * @sat: address to search for
1089 *
1090 * Pick a source port when one is not given. If we can find a suitable free
1091 * one, we insert the socket into the tables using it.
1092 *
1093 * This whole operation must be atomic.
1094 */
atalk_pick_and_bind_port(struct sock * sk,struct sockaddr_at * sat)1095 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1096 {
1097 int retval;
1098
1099 write_lock_bh(&atalk_sockets_lock);
1100
1101 for (sat->sat_port = ATPORT_RESERVED;
1102 sat->sat_port < ATPORT_LAST;
1103 sat->sat_port++) {
1104 struct sock *s;
1105
1106 sk_for_each(s, &atalk_sockets) {
1107 struct atalk_sock *at = at_sk(s);
1108
1109 if (at->src_net == sat->sat_addr.s_net &&
1110 at->src_node == sat->sat_addr.s_node &&
1111 at->src_port == sat->sat_port)
1112 goto try_next_port;
1113 }
1114
1115 /* Wheee, it's free, assign and insert. */
1116 __atalk_insert_socket(sk);
1117 at_sk(sk)->src_port = sat->sat_port;
1118 retval = 0;
1119 goto out;
1120
1121 try_next_port:;
1122 }
1123
1124 retval = -EBUSY;
1125 out:
1126 write_unlock_bh(&atalk_sockets_lock);
1127 return retval;
1128 }
1129
atalk_autobind(struct sock * sk)1130 static int atalk_autobind(struct sock *sk)
1131 {
1132 struct atalk_sock *at = at_sk(sk);
1133 struct sockaddr_at sat;
1134 struct atalk_addr *ap = atalk_find_primary();
1135 int n = -EADDRNOTAVAIL;
1136
1137 if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1138 goto out;
1139
1140 at->src_net = sat.sat_addr.s_net = ap->s_net;
1141 at->src_node = sat.sat_addr.s_node = ap->s_node;
1142
1143 n = atalk_pick_and_bind_port(sk, &sat);
1144 if (!n)
1145 sock_reset_flag(sk, SOCK_ZAPPED);
1146 out:
1147 return n;
1148 }
1149
1150 /* Set the address 'our end' of the connection */
atalk_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)1151 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1152 {
1153 struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1154 struct sock *sk = sock->sk;
1155 struct atalk_sock *at = at_sk(sk);
1156 int err;
1157
1158 if (!sock_flag(sk, SOCK_ZAPPED) ||
1159 addr_len != sizeof(struct sockaddr_at))
1160 return -EINVAL;
1161
1162 if (addr->sat_family != AF_APPLETALK)
1163 return -EAFNOSUPPORT;
1164
1165 lock_sock(sk);
1166 if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1167 struct atalk_addr *ap = atalk_find_primary();
1168
1169 err = -EADDRNOTAVAIL;
1170 if (!ap)
1171 goto out;
1172
1173 at->src_net = addr->sat_addr.s_net = ap->s_net;
1174 at->src_node = addr->sat_addr.s_node = ap->s_node;
1175 } else {
1176 err = -EADDRNOTAVAIL;
1177 if (!atalk_find_interface(addr->sat_addr.s_net,
1178 addr->sat_addr.s_node))
1179 goto out;
1180
1181 at->src_net = addr->sat_addr.s_net;
1182 at->src_node = addr->sat_addr.s_node;
1183 }
1184
1185 if (addr->sat_port == ATADDR_ANYPORT) {
1186 err = atalk_pick_and_bind_port(sk, addr);
1187
1188 if (err < 0)
1189 goto out;
1190 } else {
1191 at->src_port = addr->sat_port;
1192
1193 err = -EADDRINUSE;
1194 if (atalk_find_or_insert_socket(sk, addr))
1195 goto out;
1196 }
1197
1198 sock_reset_flag(sk, SOCK_ZAPPED);
1199 err = 0;
1200 out:
1201 release_sock(sk);
1202 return err;
1203 }
1204
1205 /* Set the address we talk to */
atalk_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)1206 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1207 int addr_len, int flags)
1208 {
1209 struct sock *sk = sock->sk;
1210 struct atalk_sock *at = at_sk(sk);
1211 struct sockaddr_at *addr;
1212 int err;
1213
1214 sk->sk_state = TCP_CLOSE;
1215 sock->state = SS_UNCONNECTED;
1216
1217 if (addr_len != sizeof(*addr))
1218 return -EINVAL;
1219
1220 addr = (struct sockaddr_at *)uaddr;
1221
1222 if (addr->sat_family != AF_APPLETALK)
1223 return -EAFNOSUPPORT;
1224
1225 if (addr->sat_addr.s_node == ATADDR_BCAST &&
1226 !sock_flag(sk, SOCK_BROADCAST)) {
1227 #if 1
1228 pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
1229 current->comm);
1230 #else
1231 return -EACCES;
1232 #endif
1233 }
1234
1235 lock_sock(sk);
1236 err = -EBUSY;
1237 if (sock_flag(sk, SOCK_ZAPPED))
1238 if (atalk_autobind(sk) < 0)
1239 goto out;
1240
1241 err = -ENETUNREACH;
1242 if (!atrtr_get_dev(&addr->sat_addr))
1243 goto out;
1244
1245 at->dest_port = addr->sat_port;
1246 at->dest_net = addr->sat_addr.s_net;
1247 at->dest_node = addr->sat_addr.s_node;
1248
1249 sock->state = SS_CONNECTED;
1250 sk->sk_state = TCP_ESTABLISHED;
1251 err = 0;
1252 out:
1253 release_sock(sk);
1254 return err;
1255 }
1256
1257 /*
1258 * Find the name of an AppleTalk socket. Just copy the right
1259 * fields into the sockaddr.
1260 */
atalk_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1261 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1262 int peer)
1263 {
1264 struct sockaddr_at sat;
1265 struct sock *sk = sock->sk;
1266 struct atalk_sock *at = at_sk(sk);
1267 int err;
1268
1269 lock_sock(sk);
1270 err = -ENOBUFS;
1271 if (sock_flag(sk, SOCK_ZAPPED))
1272 if (atalk_autobind(sk) < 0)
1273 goto out;
1274
1275 memset(&sat, 0, sizeof(sat));
1276
1277 if (peer) {
1278 err = -ENOTCONN;
1279 if (sk->sk_state != TCP_ESTABLISHED)
1280 goto out;
1281
1282 sat.sat_addr.s_net = at->dest_net;
1283 sat.sat_addr.s_node = at->dest_node;
1284 sat.sat_port = at->dest_port;
1285 } else {
1286 sat.sat_addr.s_net = at->src_net;
1287 sat.sat_addr.s_node = at->src_node;
1288 sat.sat_port = at->src_port;
1289 }
1290
1291 sat.sat_family = AF_APPLETALK;
1292 memcpy(uaddr, &sat, sizeof(sat));
1293 err = sizeof(struct sockaddr_at);
1294
1295 out:
1296 release_sock(sk);
1297 return err;
1298 }
1299
atalk_route_packet(struct sk_buff * skb,struct net_device * dev,struct ddpehdr * ddp,__u16 len_hops,int origlen)1300 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1301 struct ddpehdr *ddp, __u16 len_hops, int origlen)
1302 {
1303 struct atalk_route *rt;
1304 struct atalk_addr ta;
1305
1306 /*
1307 * Don't route multicast, etc., packets, or packets sent to "this
1308 * network"
1309 */
1310 if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1311 /*
1312 * FIXME:
1313 *
1314 * Can it ever happen that a packet is from a PPP iface and
1315 * needs to be broadcast onto the default network?
1316 */
1317 if (dev->type == ARPHRD_PPP)
1318 printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1319 "packet received from PPP iface\n");
1320 goto free_it;
1321 }
1322
1323 ta.s_net = ddp->deh_dnet;
1324 ta.s_node = ddp->deh_dnode;
1325
1326 /* Route the packet */
1327 rt = atrtr_find(&ta);
1328 /* increment hops count */
1329 len_hops += 1 << 10;
1330 if (!rt || !(len_hops & (15 << 10)))
1331 goto free_it;
1332
1333 /* FIXME: use skb->cb to be able to use shared skbs */
1334
1335 /*
1336 * Route goes through another gateway, so set the target to the
1337 * gateway instead.
1338 */
1339
1340 if (rt->flags & RTF_GATEWAY) {
1341 ta.s_net = rt->gateway.s_net;
1342 ta.s_node = rt->gateway.s_node;
1343 }
1344
1345 /* Fix up skb->len field */
1346 skb_trim(skb, min_t(unsigned int, origlen,
1347 (rt->dev->hard_header_len +
1348 ddp_dl->header_length + (len_hops & 1023))));
1349
1350 /* FIXME: use skb->cb to be able to use shared skbs */
1351 ddp->deh_len_hops = htons(len_hops);
1352
1353 /*
1354 * Send the buffer onwards
1355 *
1356 * Now we must always be careful. If it's come from LocalTalk to
1357 * EtherTalk it might not fit
1358 *
1359 * Order matters here: If a packet has to be copied to make a new
1360 * headroom (rare hopefully) then it won't need unsharing.
1361 *
1362 * Note. ddp-> becomes invalid at the realloc.
1363 */
1364 if (skb_headroom(skb) < 22) {
1365 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1366 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1367 kfree_skb(skb);
1368 skb = nskb;
1369 } else
1370 skb = skb_unshare(skb, GFP_ATOMIC);
1371
1372 /*
1373 * If the buffer didn't vanish into the lack of space bitbucket we can
1374 * send it.
1375 */
1376 if (skb == NULL)
1377 goto drop;
1378
1379 if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1380 return NET_RX_DROP;
1381 return NET_RX_SUCCESS;
1382 free_it:
1383 kfree_skb(skb);
1384 drop:
1385 return NET_RX_DROP;
1386 }
1387
1388 /**
1389 * atalk_rcv - Receive a packet (in skb) from device dev
1390 * @skb: packet received
1391 * @dev: network device where the packet comes from
1392 * @pt: packet type
1393 * @orig_dev: the original receive net device
1394 *
1395 * Receive a packet (in skb) from device dev. This has come from the SNAP
1396 * decoder, and on entry skb->transport_header is the DDP header, skb->len
1397 * is the DDP header, skb->len is the DDP length. The physical headers
1398 * have been extracted. PPP should probably pass frames marked as for this
1399 * layer. [ie ARPHRD_ETHERTALK]
1400 */
atalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1401 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1402 struct packet_type *pt, struct net_device *orig_dev)
1403 {
1404 struct ddpehdr *ddp;
1405 struct sock *sock;
1406 struct atalk_iface *atif;
1407 struct sockaddr_at tosat;
1408 int origlen;
1409 __u16 len_hops;
1410
1411 if (!net_eq(dev_net(dev), &init_net))
1412 goto drop;
1413
1414 /* Don't mangle buffer if shared */
1415 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1416 goto out;
1417
1418 /* Size check and make sure header is contiguous */
1419 if (!pskb_may_pull(skb, sizeof(*ddp)))
1420 goto drop;
1421
1422 ddp = ddp_hdr(skb);
1423
1424 len_hops = ntohs(ddp->deh_len_hops);
1425
1426 /* Trim buffer in case of stray trailing data */
1427 origlen = skb->len;
1428 skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1429
1430 /*
1431 * Size check to see if ddp->deh_len was crap
1432 * (Otherwise we'll detonate most spectacularly
1433 * in the middle of atalk_checksum() or recvmsg()).
1434 */
1435 if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1436 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1437 "skb->len=%u)\n", len_hops & 1023, skb->len);
1438 goto drop;
1439 }
1440
1441 /*
1442 * Any checksums. Note we don't do htons() on this == is assumed to be
1443 * valid for net byte orders all over the networking code...
1444 */
1445 if (ddp->deh_sum &&
1446 atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1447 /* Not a valid AppleTalk frame - dustbin time */
1448 goto drop;
1449
1450 /* Check the packet is aimed at us */
1451 if (!ddp->deh_dnet) /* Net 0 is 'this network' */
1452 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1453 else
1454 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1455
1456 if (!atif) {
1457 /* Not ours, so we route the packet via the correct
1458 * AppleTalk iface
1459 */
1460 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1461 }
1462
1463 /*
1464 * Which socket - atalk_search_socket() looks for a *full match*
1465 * of the <net, node, port> tuple.
1466 */
1467 tosat.sat_addr.s_net = ddp->deh_dnet;
1468 tosat.sat_addr.s_node = ddp->deh_dnode;
1469 tosat.sat_port = ddp->deh_dport;
1470
1471 sock = atalk_search_socket(&tosat, atif);
1472 if (!sock) /* But not one of our sockets */
1473 goto drop;
1474
1475 /* Queue packet (standard) */
1476 if (sock_queue_rcv_skb(sock, skb) < 0)
1477 goto drop;
1478
1479 return NET_RX_SUCCESS;
1480
1481 drop:
1482 kfree_skb(skb);
1483 out:
1484 return NET_RX_DROP;
1485
1486 }
1487
1488 /*
1489 * Receive a LocalTalk frame. We make some demands on the caller here.
1490 * Caller must provide enough headroom on the packet to pull the short
1491 * header and append a long one.
1492 */
ltalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1493 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1494 struct packet_type *pt, struct net_device *orig_dev)
1495 {
1496 if (!net_eq(dev_net(dev), &init_net))
1497 goto freeit;
1498
1499 /* Expand any short form frames */
1500 if (skb_mac_header(skb)[2] == 1) {
1501 struct ddpehdr *ddp;
1502 /* Find our address */
1503 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1504
1505 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1506 goto freeit;
1507
1508 /* Don't mangle buffer if shared */
1509 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1510 return 0;
1511
1512 /*
1513 * The push leaves us with a ddephdr not an shdr, and
1514 * handily the port bytes in the right place preset.
1515 */
1516 ddp = skb_push(skb, sizeof(*ddp) - 4);
1517
1518 /* Now fill in the long header */
1519
1520 /*
1521 * These two first. The mac overlays the new source/dest
1522 * network information so we MUST copy these before
1523 * we write the network numbers !
1524 */
1525
1526 ddp->deh_dnode = skb_mac_header(skb)[0]; /* From physical header */
1527 ddp->deh_snode = skb_mac_header(skb)[1]; /* From physical header */
1528
1529 ddp->deh_dnet = ap->s_net; /* Network number */
1530 ddp->deh_snet = ap->s_net;
1531 ddp->deh_sum = 0; /* No checksum */
1532 /*
1533 * Not sure about this bit...
1534 */
1535 /* Non routable, so force a drop if we slip up later */
1536 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1537 }
1538 skb_reset_transport_header(skb);
1539
1540 return atalk_rcv(skb, dev, pt, orig_dev);
1541 freeit:
1542 kfree_skb(skb);
1543 return 0;
1544 }
1545
atalk_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)1546 static int atalk_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1547 {
1548 struct sock *sk = sock->sk;
1549 struct atalk_sock *at = at_sk(sk);
1550 DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
1551 int flags = msg->msg_flags;
1552 int loopback = 0;
1553 struct sockaddr_at local_satalk, gsat;
1554 struct sk_buff *skb;
1555 struct net_device *dev;
1556 struct ddpehdr *ddp;
1557 int size, hard_header_len;
1558 struct atalk_route *rt, *rt_lo = NULL;
1559 int err;
1560
1561 if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1562 return -EINVAL;
1563
1564 if (len > DDP_MAXSZ)
1565 return -EMSGSIZE;
1566
1567 lock_sock(sk);
1568 if (usat) {
1569 err = -EBUSY;
1570 if (sock_flag(sk, SOCK_ZAPPED))
1571 if (atalk_autobind(sk) < 0)
1572 goto out;
1573
1574 err = -EINVAL;
1575 if (msg->msg_namelen < sizeof(*usat) ||
1576 usat->sat_family != AF_APPLETALK)
1577 goto out;
1578
1579 err = -EPERM;
1580 /* netatalk didn't implement this check */
1581 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1582 !sock_flag(sk, SOCK_BROADCAST)) {
1583 goto out;
1584 }
1585 } else {
1586 err = -ENOTCONN;
1587 if (sk->sk_state != TCP_ESTABLISHED)
1588 goto out;
1589 usat = &local_satalk;
1590 usat->sat_family = AF_APPLETALK;
1591 usat->sat_port = at->dest_port;
1592 usat->sat_addr.s_node = at->dest_node;
1593 usat->sat_addr.s_net = at->dest_net;
1594 }
1595
1596 /* Build a packet */
1597 net_dbg_ratelimited("SK %p: Got address.\n", sk);
1598
1599 /* For headers */
1600 size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1601
1602 if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1603 rt = atrtr_find(&usat->sat_addr);
1604 } else {
1605 struct atalk_addr at_hint;
1606
1607 at_hint.s_node = 0;
1608 at_hint.s_net = at->src_net;
1609
1610 rt = atrtr_find(&at_hint);
1611 }
1612 err = -ENETUNREACH;
1613 if (!rt)
1614 goto out;
1615
1616 dev = rt->dev;
1617
1618 net_dbg_ratelimited("SK %p: Size needed %d, device %s\n",
1619 sk, size, dev->name);
1620
1621 hard_header_len = dev->hard_header_len;
1622 /* Leave room for loopback hardware header if necessary */
1623 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1624 (dev->flags & IFF_LOOPBACK || !(rt->flags & RTF_GATEWAY))) {
1625 struct atalk_addr at_lo;
1626
1627 at_lo.s_node = 0;
1628 at_lo.s_net = 0;
1629
1630 rt_lo = atrtr_find(&at_lo);
1631
1632 if (rt_lo && rt_lo->dev->hard_header_len > hard_header_len)
1633 hard_header_len = rt_lo->dev->hard_header_len;
1634 }
1635
1636 size += hard_header_len;
1637 release_sock(sk);
1638 skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1639 lock_sock(sk);
1640 if (!skb)
1641 goto out;
1642
1643 skb_reserve(skb, ddp_dl->header_length);
1644 skb_reserve(skb, hard_header_len);
1645 skb->dev = dev;
1646
1647 net_dbg_ratelimited("SK %p: Begin build.\n", sk);
1648
1649 ddp = skb_put(skb, sizeof(struct ddpehdr));
1650 ddp->deh_len_hops = htons(len + sizeof(*ddp));
1651 ddp->deh_dnet = usat->sat_addr.s_net;
1652 ddp->deh_snet = at->src_net;
1653 ddp->deh_dnode = usat->sat_addr.s_node;
1654 ddp->deh_snode = at->src_node;
1655 ddp->deh_dport = usat->sat_port;
1656 ddp->deh_sport = at->src_port;
1657
1658 net_dbg_ratelimited("SK %p: Copy user data (%zd bytes).\n", sk, len);
1659
1660 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1661 if (err) {
1662 kfree_skb(skb);
1663 err = -EFAULT;
1664 goto out;
1665 }
1666
1667 if (sk->sk_no_check_tx)
1668 ddp->deh_sum = 0;
1669 else
1670 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1671
1672 /*
1673 * Loopback broadcast packets to non gateway targets (ie routes
1674 * to group we are in)
1675 */
1676 if (ddp->deh_dnode == ATADDR_BCAST &&
1677 !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1678 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1679
1680 if (skb2) {
1681 loopback = 1;
1682 net_dbg_ratelimited("SK %p: send out(copy).\n", sk);
1683 /*
1684 * If it fails it is queued/sent above in the aarp queue
1685 */
1686 aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1687 }
1688 }
1689
1690 if (dev->flags & IFF_LOOPBACK || loopback) {
1691 net_dbg_ratelimited("SK %p: Loop back.\n", sk);
1692 /* loop back */
1693 skb_orphan(skb);
1694 if (ddp->deh_dnode == ATADDR_BCAST) {
1695 if (!rt_lo) {
1696 kfree_skb(skb);
1697 err = -ENETUNREACH;
1698 goto out;
1699 }
1700 dev = rt_lo->dev;
1701 skb->dev = dev;
1702 }
1703 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1704 } else {
1705 net_dbg_ratelimited("SK %p: send out.\n", sk);
1706 if (rt->flags & RTF_GATEWAY) {
1707 gsat.sat_addr = rt->gateway;
1708 usat = &gsat;
1709 }
1710
1711 /*
1712 * If it fails it is queued/sent above in the aarp queue
1713 */
1714 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1715 }
1716 net_dbg_ratelimited("SK %p: Done write (%zd).\n", sk, len);
1717
1718 out:
1719 release_sock(sk);
1720 return err ? : len;
1721 }
1722
atalk_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1723 static int atalk_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1724 int flags)
1725 {
1726 struct sock *sk = sock->sk;
1727 struct ddpehdr *ddp;
1728 int copied = 0;
1729 int offset = 0;
1730 int err = 0;
1731 struct sk_buff *skb;
1732
1733 skb = skb_recv_datagram(sk, flags, &err);
1734 lock_sock(sk);
1735
1736 if (!skb)
1737 goto out;
1738
1739 /* FIXME: use skb->cb to be able to use shared skbs */
1740 ddp = ddp_hdr(skb);
1741 copied = ntohs(ddp->deh_len_hops) & 1023;
1742
1743 if (sk->sk_type != SOCK_RAW) {
1744 offset = sizeof(*ddp);
1745 copied -= offset;
1746 }
1747
1748 if (copied > size) {
1749 copied = size;
1750 msg->msg_flags |= MSG_TRUNC;
1751 }
1752 err = skb_copy_datagram_msg(skb, offset, msg, copied);
1753
1754 if (!err && msg->msg_name) {
1755 DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
1756 sat->sat_family = AF_APPLETALK;
1757 sat->sat_port = ddp->deh_sport;
1758 sat->sat_addr.s_node = ddp->deh_snode;
1759 sat->sat_addr.s_net = ddp->deh_snet;
1760 msg->msg_namelen = sizeof(*sat);
1761 }
1762
1763 skb_free_datagram(sk, skb); /* Free the datagram. */
1764
1765 out:
1766 release_sock(sk);
1767 return err ? : copied;
1768 }
1769
1770
1771 /*
1772 * AppleTalk ioctl calls.
1773 */
atalk_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1774 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1775 {
1776 int rc = -ENOIOCTLCMD;
1777 struct sock *sk = sock->sk;
1778 void __user *argp = (void __user *)arg;
1779
1780 switch (cmd) {
1781 /* Protocol layer */
1782 case TIOCOUTQ: {
1783 long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1784
1785 if (amount < 0)
1786 amount = 0;
1787 rc = put_user(amount, (int __user *)argp);
1788 break;
1789 }
1790 case TIOCINQ: {
1791 struct sk_buff *skb;
1792 long amount = 0;
1793
1794 spin_lock_irq(&sk->sk_receive_queue.lock);
1795 skb = skb_peek(&sk->sk_receive_queue);
1796 if (skb)
1797 amount = skb->len - sizeof(struct ddpehdr);
1798 spin_unlock_irq(&sk->sk_receive_queue.lock);
1799 rc = put_user(amount, (int __user *)argp);
1800 break;
1801 }
1802 /* Routing */
1803 case SIOCADDRT:
1804 case SIOCDELRT:
1805 rc = -EPERM;
1806 if (capable(CAP_NET_ADMIN))
1807 rc = atrtr_ioctl(cmd, argp);
1808 break;
1809 /* Interface */
1810 case SIOCGIFADDR:
1811 case SIOCSIFADDR:
1812 case SIOCGIFBRDADDR:
1813 case SIOCATALKDIFADDR:
1814 case SIOCDIFADDR:
1815 case SIOCSARP: /* proxy AARP */
1816 case SIOCDARP: /* proxy AARP */
1817 rtnl_lock();
1818 rc = atif_ioctl(cmd, argp);
1819 rtnl_unlock();
1820 break;
1821 }
1822
1823 return rc;
1824 }
1825
1826
1827 #ifdef CONFIG_COMPAT
atalk_compat_routing_ioctl(struct sock * sk,unsigned int cmd,struct compat_rtentry __user * ur)1828 static int atalk_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1829 struct compat_rtentry __user *ur)
1830 {
1831 compat_uptr_t rtdev;
1832 struct rtentry rt;
1833
1834 if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1835 3 * sizeof(struct sockaddr)) ||
1836 get_user(rt.rt_flags, &ur->rt_flags) ||
1837 get_user(rt.rt_metric, &ur->rt_metric) ||
1838 get_user(rt.rt_mtu, &ur->rt_mtu) ||
1839 get_user(rt.rt_window, &ur->rt_window) ||
1840 get_user(rt.rt_irtt, &ur->rt_irtt) ||
1841 get_user(rtdev, &ur->rt_dev))
1842 return -EFAULT;
1843
1844 switch (cmd) {
1845 case SIOCDELRT:
1846 if (rt.rt_dst.sa_family != AF_APPLETALK)
1847 return -EINVAL;
1848 return atrtr_delete(&((struct sockaddr_at *)
1849 &rt.rt_dst)->sat_addr);
1850
1851 case SIOCADDRT:
1852 rt.rt_dev = compat_ptr(rtdev);
1853 return atrtr_ioctl_addrt(&rt);
1854 default:
1855 return -EINVAL;
1856 }
1857 }
atalk_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1858 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1859 {
1860 void __user *argp = compat_ptr(arg);
1861 struct sock *sk = sock->sk;
1862
1863 switch (cmd) {
1864 case SIOCADDRT:
1865 case SIOCDELRT:
1866 return atalk_compat_routing_ioctl(sk, cmd, argp);
1867 /*
1868 * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1869 * cannot handle it in common code. The data we access if ifreq
1870 * here is compatible, so we can simply call the native
1871 * handler.
1872 */
1873 case SIOCATALKDIFADDR:
1874 return atalk_ioctl(sock, cmd, (unsigned long)argp);
1875 default:
1876 return -ENOIOCTLCMD;
1877 }
1878 }
1879 #endif /* CONFIG_COMPAT */
1880
1881
1882 static const struct net_proto_family atalk_family_ops = {
1883 .family = PF_APPLETALK,
1884 .create = atalk_create,
1885 .owner = THIS_MODULE,
1886 };
1887
1888 static const struct proto_ops atalk_dgram_ops = {
1889 .family = PF_APPLETALK,
1890 .owner = THIS_MODULE,
1891 .release = atalk_release,
1892 .bind = atalk_bind,
1893 .connect = atalk_connect,
1894 .socketpair = sock_no_socketpair,
1895 .accept = sock_no_accept,
1896 .getname = atalk_getname,
1897 .poll = datagram_poll,
1898 .ioctl = atalk_ioctl,
1899 .gettstamp = sock_gettstamp,
1900 #ifdef CONFIG_COMPAT
1901 .compat_ioctl = atalk_compat_ioctl,
1902 #endif
1903 .listen = sock_no_listen,
1904 .shutdown = sock_no_shutdown,
1905 .sendmsg = atalk_sendmsg,
1906 .recvmsg = atalk_recvmsg,
1907 .mmap = sock_no_mmap,
1908 };
1909
1910 static struct notifier_block ddp_notifier = {
1911 .notifier_call = ddp_device_event,
1912 };
1913
1914 static struct packet_type ltalk_packet_type __read_mostly = {
1915 .type = cpu_to_be16(ETH_P_LOCALTALK),
1916 .func = ltalk_rcv,
1917 };
1918
1919 static struct packet_type ppptalk_packet_type __read_mostly = {
1920 .type = cpu_to_be16(ETH_P_PPPTALK),
1921 .func = atalk_rcv,
1922 };
1923
1924 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1925
1926 /* Export symbols for use by drivers when AppleTalk is a module */
1927 EXPORT_SYMBOL(atrtr_get_dev);
1928 EXPORT_SYMBOL(atalk_find_dev_addr);
1929
1930 /* Called by proto.c on kernel start up */
atalk_init(void)1931 static int __init atalk_init(void)
1932 {
1933 int rc;
1934
1935 rc = proto_register(&ddp_proto, 0);
1936 if (rc)
1937 goto out;
1938
1939 rc = sock_register(&atalk_family_ops);
1940 if (rc)
1941 goto out_proto;
1942
1943 ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1944 if (!ddp_dl) {
1945 pr_crit("Unable to register DDP with SNAP.\n");
1946 rc = -ENOMEM;
1947 goto out_sock;
1948 }
1949
1950 dev_add_pack(<alk_packet_type);
1951 dev_add_pack(&ppptalk_packet_type);
1952
1953 rc = register_netdevice_notifier(&ddp_notifier);
1954 if (rc)
1955 goto out_snap;
1956
1957 rc = aarp_proto_init();
1958 if (rc)
1959 goto out_dev;
1960
1961 rc = atalk_proc_init();
1962 if (rc)
1963 goto out_aarp;
1964
1965 rc = atalk_register_sysctl();
1966 if (rc)
1967 goto out_proc;
1968 out:
1969 return rc;
1970 out_proc:
1971 atalk_proc_exit();
1972 out_aarp:
1973 aarp_cleanup_module();
1974 out_dev:
1975 unregister_netdevice_notifier(&ddp_notifier);
1976 out_snap:
1977 dev_remove_pack(&ppptalk_packet_type);
1978 dev_remove_pack(<alk_packet_type);
1979 unregister_snap_client(ddp_dl);
1980 out_sock:
1981 sock_unregister(PF_APPLETALK);
1982 out_proto:
1983 proto_unregister(&ddp_proto);
1984 goto out;
1985 }
1986 module_init(atalk_init);
1987
1988 /*
1989 * No explicit module reference count manipulation is needed in the
1990 * protocol. Socket layer sets module reference count for us
1991 * and interfaces reference counting is done
1992 * by the network device layer.
1993 *
1994 * Ergo, before the AppleTalk module can be removed, all AppleTalk
1995 * sockets should be closed from user space.
1996 */
atalk_exit(void)1997 static void __exit atalk_exit(void)
1998 {
1999 #ifdef CONFIG_SYSCTL
2000 atalk_unregister_sysctl();
2001 #endif /* CONFIG_SYSCTL */
2002 atalk_proc_exit();
2003 aarp_cleanup_module(); /* General aarp clean-up. */
2004 unregister_netdevice_notifier(&ddp_notifier);
2005 dev_remove_pack(<alk_packet_type);
2006 dev_remove_pack(&ppptalk_packet_type);
2007 unregister_snap_client(ddp_dl);
2008 sock_unregister(PF_APPLETALK);
2009 proto_unregister(&ddp_proto);
2010 }
2011 module_exit(atalk_exit);
2012
2013 MODULE_LICENSE("GPL");
2014 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
2015 MODULE_DESCRIPTION("AppleTalk 0.20\n");
2016 MODULE_ALIAS_NETPROTO(PF_APPLETALK);
2017