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 *s;
92
93 read_lock_bh(&atalk_sockets_lock);
94 sk_for_each(s, &atalk_sockets) {
95 struct atalk_sock *at = at_sk(s);
96
97 if (to->sat_port != at->src_port)
98 continue;
99
100 if (to->sat_addr.s_net == ATADDR_ANYNET &&
101 to->sat_addr.s_node == ATADDR_BCAST)
102 goto found;
103
104 if (to->sat_addr.s_net == at->src_net &&
105 (to->sat_addr.s_node == at->src_node ||
106 to->sat_addr.s_node == ATADDR_BCAST ||
107 to->sat_addr.s_node == ATADDR_ANYNODE))
108 goto found;
109
110 /* XXXX.0 -- we got a request for this router. make sure
111 * that the node is appropriately set. */
112 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
113 to->sat_addr.s_net != ATADDR_ANYNET &&
114 atif->address.s_node == at->src_node) {
115 to->sat_addr.s_node = atif->address.s_node;
116 goto found;
117 }
118 }
119 s = NULL;
120 found:
121 read_unlock_bh(&atalk_sockets_lock);
122 return s;
123 }
124
125 /**
126 * atalk_find_or_insert_socket - Try to find a socket matching ADDR
127 * @sk: socket to insert in the list if it is not there already
128 * @sat: address to search for
129 *
130 * Try to find a socket matching ADDR in the socket list, if found then return
131 * it. If not, insert SK into the socket list.
132 *
133 * This entire operation must execute atomically.
134 */
atalk_find_or_insert_socket(struct sock * sk,struct sockaddr_at * sat)135 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
136 struct sockaddr_at *sat)
137 {
138 struct sock *s;
139 struct atalk_sock *at;
140
141 write_lock_bh(&atalk_sockets_lock);
142 sk_for_each(s, &atalk_sockets) {
143 at = at_sk(s);
144
145 if (at->src_net == sat->sat_addr.s_net &&
146 at->src_node == sat->sat_addr.s_node &&
147 at->src_port == sat->sat_port)
148 goto found;
149 }
150 s = NULL;
151 __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
152 found:
153 write_unlock_bh(&atalk_sockets_lock);
154 return s;
155 }
156
atalk_destroy_timer(struct timer_list * t)157 static void atalk_destroy_timer(struct timer_list *t)
158 {
159 struct sock *sk = from_timer(sk, t, sk_timer);
160
161 if (sk_has_allocations(sk)) {
162 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
163 add_timer(&sk->sk_timer);
164 } else
165 sock_put(sk);
166 }
167
atalk_destroy_socket(struct sock * sk)168 static inline void atalk_destroy_socket(struct sock *sk)
169 {
170 atalk_remove_socket(sk);
171 skb_queue_purge(&sk->sk_receive_queue);
172
173 if (sk_has_allocations(sk)) {
174 timer_setup(&sk->sk_timer, atalk_destroy_timer, 0);
175 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
176 add_timer(&sk->sk_timer);
177 } else
178 sock_put(sk);
179 }
180
181 /**************************************************************************\
182 * *
183 * Routing tables for the AppleTalk socket layer. *
184 * *
185 \**************************************************************************/
186
187 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
188 struct atalk_route *atalk_routes;
189 DEFINE_RWLOCK(atalk_routes_lock);
190
191 struct atalk_iface *atalk_interfaces;
192 DEFINE_RWLOCK(atalk_interfaces_lock);
193
194 /* For probing devices or in a routerless network */
195 struct atalk_route atrtr_default;
196
197 /* AppleTalk interface control */
198 /*
199 * Drop a device. Doesn't drop any of its routes - that is the caller's
200 * problem. Called when we down the interface or delete the address.
201 */
atif_drop_device(struct net_device * dev)202 static void atif_drop_device(struct net_device *dev)
203 {
204 struct atalk_iface **iface = &atalk_interfaces;
205 struct atalk_iface *tmp;
206
207 write_lock_bh(&atalk_interfaces_lock);
208 while ((tmp = *iface) != NULL) {
209 if (tmp->dev == dev) {
210 *iface = tmp->next;
211 dev_put(dev);
212 kfree(tmp);
213 dev->atalk_ptr = NULL;
214 } else
215 iface = &tmp->next;
216 }
217 write_unlock_bh(&atalk_interfaces_lock);
218 }
219
atif_add_device(struct net_device * dev,struct atalk_addr * sa)220 static struct atalk_iface *atif_add_device(struct net_device *dev,
221 struct atalk_addr *sa)
222 {
223 struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
224
225 if (!iface)
226 goto out;
227
228 dev_hold(dev);
229 iface->dev = dev;
230 dev->atalk_ptr = iface;
231 iface->address = *sa;
232 iface->status = 0;
233
234 write_lock_bh(&atalk_interfaces_lock);
235 iface->next = atalk_interfaces;
236 atalk_interfaces = iface;
237 write_unlock_bh(&atalk_interfaces_lock);
238 out:
239 return iface;
240 }
241
242 /* Perform phase 2 AARP probing on our tentative address */
atif_probe_device(struct atalk_iface * atif)243 static int atif_probe_device(struct atalk_iface *atif)
244 {
245 int netrange = ntohs(atif->nets.nr_lastnet) -
246 ntohs(atif->nets.nr_firstnet) + 1;
247 int probe_net = ntohs(atif->address.s_net);
248 int probe_node = atif->address.s_node;
249 int netct, nodect;
250
251 /* Offset the network we start probing with */
252 if (probe_net == ATADDR_ANYNET) {
253 probe_net = ntohs(atif->nets.nr_firstnet);
254 if (netrange)
255 probe_net += jiffies % netrange;
256 }
257 if (probe_node == ATADDR_ANYNODE)
258 probe_node = jiffies & 0xFF;
259
260 /* Scan the networks */
261 atif->status |= ATIF_PROBE;
262 for (netct = 0; netct <= netrange; netct++) {
263 /* Sweep the available nodes from a given start */
264 atif->address.s_net = htons(probe_net);
265 for (nodect = 0; nodect < 256; nodect++) {
266 atif->address.s_node = (nodect + probe_node) & 0xFF;
267 if (atif->address.s_node > 0 &&
268 atif->address.s_node < 254) {
269 /* Probe a proposed address */
270 aarp_probe_network(atif);
271
272 if (!(atif->status & ATIF_PROBE_FAIL)) {
273 atif->status &= ~ATIF_PROBE;
274 return 0;
275 }
276 }
277 atif->status &= ~ATIF_PROBE_FAIL;
278 }
279 probe_net++;
280 if (probe_net > ntohs(atif->nets.nr_lastnet))
281 probe_net = ntohs(atif->nets.nr_firstnet);
282 }
283 atif->status &= ~ATIF_PROBE;
284
285 return -EADDRINUSE; /* Network is full... */
286 }
287
288
289 /* Perform AARP probing for a proxy address */
atif_proxy_probe_device(struct atalk_iface * atif,struct atalk_addr * proxy_addr)290 static int atif_proxy_probe_device(struct atalk_iface *atif,
291 struct atalk_addr *proxy_addr)
292 {
293 int netrange = ntohs(atif->nets.nr_lastnet) -
294 ntohs(atif->nets.nr_firstnet) + 1;
295 /* we probe the interface's network */
296 int probe_net = ntohs(atif->address.s_net);
297 int probe_node = ATADDR_ANYNODE; /* we'll take anything */
298 int netct, nodect;
299
300 /* Offset the network we start probing with */
301 if (probe_net == ATADDR_ANYNET) {
302 probe_net = ntohs(atif->nets.nr_firstnet);
303 if (netrange)
304 probe_net += jiffies % netrange;
305 }
306
307 if (probe_node == ATADDR_ANYNODE)
308 probe_node = jiffies & 0xFF;
309
310 /* Scan the networks */
311 for (netct = 0; netct <= netrange; netct++) {
312 /* Sweep the available nodes from a given start */
313 proxy_addr->s_net = htons(probe_net);
314 for (nodect = 0; nodect < 256; nodect++) {
315 proxy_addr->s_node = (nodect + probe_node) & 0xFF;
316 if (proxy_addr->s_node > 0 &&
317 proxy_addr->s_node < 254) {
318 /* Tell AARP to probe a proposed address */
319 int ret = aarp_proxy_probe_network(atif,
320 proxy_addr);
321
322 if (ret != -EADDRINUSE)
323 return ret;
324 }
325 }
326 probe_net++;
327 if (probe_net > ntohs(atif->nets.nr_lastnet))
328 probe_net = ntohs(atif->nets.nr_firstnet);
329 }
330
331 return -EADDRINUSE; /* Network is full... */
332 }
333
334
atalk_find_dev_addr(struct net_device * dev)335 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
336 {
337 struct atalk_iface *iface = dev->atalk_ptr;
338 return iface ? &iface->address : NULL;
339 }
340
atalk_find_primary(void)341 static struct atalk_addr *atalk_find_primary(void)
342 {
343 struct atalk_iface *fiface = NULL;
344 struct atalk_addr *retval;
345 struct atalk_iface *iface;
346
347 /*
348 * Return a point-to-point interface only if
349 * there is no non-ptp interface available.
350 */
351 read_lock_bh(&atalk_interfaces_lock);
352 for (iface = atalk_interfaces; iface; iface = iface->next) {
353 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
354 fiface = iface;
355 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
356 retval = &iface->address;
357 goto out;
358 }
359 }
360
361 if (fiface)
362 retval = &fiface->address;
363 else if (atalk_interfaces)
364 retval = &atalk_interfaces->address;
365 else
366 retval = NULL;
367 out:
368 read_unlock_bh(&atalk_interfaces_lock);
369 return retval;
370 }
371
372 /*
373 * Find a match for 'any network' - ie any of our interfaces with that
374 * node number will do just nicely.
375 */
atalk_find_anynet(int node,struct net_device * dev)376 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
377 {
378 struct atalk_iface *iface = dev->atalk_ptr;
379
380 if (!iface || iface->status & ATIF_PROBE)
381 goto out_err;
382
383 if (node != ATADDR_BCAST &&
384 iface->address.s_node != node &&
385 node != ATADDR_ANYNODE)
386 goto out_err;
387 out:
388 return iface;
389 out_err:
390 iface = NULL;
391 goto out;
392 }
393
394 /* Find a match for a specific network:node pair */
atalk_find_interface(__be16 net,int node)395 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
396 {
397 struct atalk_iface *iface;
398
399 read_lock_bh(&atalk_interfaces_lock);
400 for (iface = atalk_interfaces; iface; iface = iface->next) {
401 if ((node == ATADDR_BCAST ||
402 node == ATADDR_ANYNODE ||
403 iface->address.s_node == node) &&
404 iface->address.s_net == net &&
405 !(iface->status & ATIF_PROBE))
406 break;
407
408 /* XXXX.0 -- net.0 returns the iface associated with net */
409 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
410 ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
411 ntohs(net) <= ntohs(iface->nets.nr_lastnet))
412 break;
413 }
414 read_unlock_bh(&atalk_interfaces_lock);
415 return iface;
416 }
417
418
419 /*
420 * Find a route for an AppleTalk packet. This ought to get cached in
421 * the socket (later on...). We know about host routes and the fact
422 * that a route must be direct to broadcast.
423 */
atrtr_find(struct atalk_addr * target)424 static struct atalk_route *atrtr_find(struct atalk_addr *target)
425 {
426 /*
427 * we must search through all routes unless we find a
428 * host route, because some host routes might overlap
429 * network routes
430 */
431 struct atalk_route *net_route = NULL;
432 struct atalk_route *r;
433
434 read_lock_bh(&atalk_routes_lock);
435 for (r = atalk_routes; r; r = r->next) {
436 if (!(r->flags & RTF_UP))
437 continue;
438
439 if (r->target.s_net == target->s_net) {
440 if (r->flags & RTF_HOST) {
441 /*
442 * if this host route is for the target,
443 * the we're done
444 */
445 if (r->target.s_node == target->s_node)
446 goto out;
447 } else
448 /*
449 * this route will work if there isn't a
450 * direct host route, so cache it
451 */
452 net_route = r;
453 }
454 }
455
456 /*
457 * if we found a network route but not a direct host
458 * route, then return it
459 */
460 if (net_route)
461 r = net_route;
462 else if (atrtr_default.dev)
463 r = &atrtr_default;
464 else /* No route can be found */
465 r = NULL;
466 out:
467 read_unlock_bh(&atalk_routes_lock);
468 return r;
469 }
470
471
472 /*
473 * Given an AppleTalk network, find the device to use. This can be
474 * a simple lookup.
475 */
atrtr_get_dev(struct atalk_addr * sa)476 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
477 {
478 struct atalk_route *atr = atrtr_find(sa);
479 return atr ? atr->dev : NULL;
480 }
481
482 /* Set up a default router */
atrtr_set_default(struct net_device * dev)483 static void atrtr_set_default(struct net_device *dev)
484 {
485 atrtr_default.dev = dev;
486 atrtr_default.flags = RTF_UP;
487 atrtr_default.gateway.s_net = htons(0);
488 atrtr_default.gateway.s_node = 0;
489 }
490
491 /*
492 * Add a router. Basically make sure it looks valid and stuff the
493 * entry in the list. While it uses netranges we always set them to one
494 * entry to work like netatalk.
495 */
atrtr_create(struct rtentry * r,struct net_device * devhint)496 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
497 {
498 struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
499 struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
500 struct atalk_route *rt;
501 struct atalk_iface *iface, *riface;
502 int retval = -EINVAL;
503
504 /*
505 * Fixme: Raise/Lower a routing change semaphore for these
506 * operations.
507 */
508
509 /* Validate the request */
510 if (ta->sat_family != AF_APPLETALK ||
511 (!devhint && ga->sat_family != AF_APPLETALK))
512 goto out;
513
514 /* Now walk the routing table and make our decisions */
515 write_lock_bh(&atalk_routes_lock);
516 for (rt = atalk_routes; rt; rt = rt->next) {
517 if (r->rt_flags != rt->flags)
518 continue;
519
520 if (ta->sat_addr.s_net == rt->target.s_net) {
521 if (!(rt->flags & RTF_HOST))
522 break;
523 if (ta->sat_addr.s_node == rt->target.s_node)
524 break;
525 }
526 }
527
528 if (!devhint) {
529 riface = NULL;
530
531 read_lock_bh(&atalk_interfaces_lock);
532 for (iface = atalk_interfaces; iface; iface = iface->next) {
533 if (!riface &&
534 ntohs(ga->sat_addr.s_net) >=
535 ntohs(iface->nets.nr_firstnet) &&
536 ntohs(ga->sat_addr.s_net) <=
537 ntohs(iface->nets.nr_lastnet))
538 riface = iface;
539
540 if (ga->sat_addr.s_net == iface->address.s_net &&
541 ga->sat_addr.s_node == iface->address.s_node)
542 riface = iface;
543 }
544 read_unlock_bh(&atalk_interfaces_lock);
545
546 retval = -ENETUNREACH;
547 if (!riface)
548 goto out_unlock;
549
550 devhint = riface->dev;
551 }
552
553 if (!rt) {
554 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
555
556 retval = -ENOBUFS;
557 if (!rt)
558 goto out_unlock;
559
560 rt->next = atalk_routes;
561 atalk_routes = rt;
562 }
563
564 /* Fill in the routing entry */
565 rt->target = ta->sat_addr;
566 dev_hold(devhint);
567 rt->dev = devhint;
568 rt->flags = r->rt_flags;
569 rt->gateway = ga->sat_addr;
570
571 retval = 0;
572 out_unlock:
573 write_unlock_bh(&atalk_routes_lock);
574 out:
575 return retval;
576 }
577
578 /* Delete a route. Find it and discard it */
atrtr_delete(struct atalk_addr * addr)579 static int atrtr_delete(struct atalk_addr *addr)
580 {
581 struct atalk_route **r = &atalk_routes;
582 int retval = 0;
583 struct atalk_route *tmp;
584
585 write_lock_bh(&atalk_routes_lock);
586 while ((tmp = *r) != NULL) {
587 if (tmp->target.s_net == addr->s_net &&
588 (!(tmp->flags&RTF_GATEWAY) ||
589 tmp->target.s_node == addr->s_node)) {
590 *r = tmp->next;
591 dev_put(tmp->dev);
592 kfree(tmp);
593 goto out;
594 }
595 r = &tmp->next;
596 }
597 retval = -ENOENT;
598 out:
599 write_unlock_bh(&atalk_routes_lock);
600 return retval;
601 }
602
603 /*
604 * Called when a device is downed. Just throw away any routes
605 * via it.
606 */
atrtr_device_down(struct net_device * dev)607 static void atrtr_device_down(struct net_device *dev)
608 {
609 struct atalk_route **r = &atalk_routes;
610 struct atalk_route *tmp;
611
612 write_lock_bh(&atalk_routes_lock);
613 while ((tmp = *r) != NULL) {
614 if (tmp->dev == dev) {
615 *r = tmp->next;
616 dev_put(dev);
617 kfree(tmp);
618 } else
619 r = &tmp->next;
620 }
621 write_unlock_bh(&atalk_routes_lock);
622
623 if (atrtr_default.dev == dev)
624 atrtr_set_default(NULL);
625 }
626
627 /* Actually down the interface */
atalk_dev_down(struct net_device * dev)628 static inline void atalk_dev_down(struct net_device *dev)
629 {
630 atrtr_device_down(dev); /* Remove all routes for the device */
631 aarp_device_down(dev); /* Remove AARP entries for the device */
632 atif_drop_device(dev); /* Remove the device */
633 }
634
635 /*
636 * A device event has occurred. Watch for devices going down and
637 * delete our use of them (iface and route).
638 */
ddp_device_event(struct notifier_block * this,unsigned long event,void * ptr)639 static int ddp_device_event(struct notifier_block *this, unsigned long event,
640 void *ptr)
641 {
642 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
643
644 if (!net_eq(dev_net(dev), &init_net))
645 return NOTIFY_DONE;
646
647 if (event == NETDEV_DOWN)
648 /* Discard any use of this */
649 atalk_dev_down(dev);
650
651 return NOTIFY_DONE;
652 }
653
654 /* ioctl calls. Shouldn't even need touching */
655 /* Device configuration ioctl calls */
atif_ioctl(int cmd,void __user * arg)656 static int atif_ioctl(int cmd, void __user *arg)
657 {
658 static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
659 struct ifreq atreq;
660 struct atalk_netrange *nr;
661 struct sockaddr_at *sa;
662 struct net_device *dev;
663 struct atalk_iface *atif;
664 int ct;
665 int limit;
666 struct rtentry rtdef;
667 int add_route;
668
669 if (get_user_ifreq(&atreq, NULL, arg))
670 return -EFAULT;
671
672 dev = __dev_get_by_name(&init_net, atreq.ifr_name);
673 if (!dev)
674 return -ENODEV;
675
676 sa = (struct sockaddr_at *)&atreq.ifr_addr;
677 atif = atalk_find_dev(dev);
678
679 switch (cmd) {
680 case SIOCSIFADDR:
681 if (!capable(CAP_NET_ADMIN))
682 return -EPERM;
683 if (sa->sat_family != AF_APPLETALK)
684 return -EINVAL;
685 if (dev->type != ARPHRD_ETHER &&
686 dev->type != ARPHRD_LOOPBACK &&
687 dev->type != ARPHRD_LOCALTLK &&
688 dev->type != ARPHRD_PPP)
689 return -EPROTONOSUPPORT;
690
691 nr = (struct atalk_netrange *)&sa->sat_zero[0];
692 add_route = 1;
693
694 /*
695 * if this is a point-to-point iface, and we already
696 * have an iface for this AppleTalk address, then we
697 * should not add a route
698 */
699 if ((dev->flags & IFF_POINTOPOINT) &&
700 atalk_find_interface(sa->sat_addr.s_net,
701 sa->sat_addr.s_node)) {
702 printk(KERN_DEBUG "AppleTalk: point-to-point "
703 "interface added with "
704 "existing address\n");
705 add_route = 0;
706 }
707
708 /*
709 * Phase 1 is fine on LocalTalk but we don't do
710 * EtherTalk phase 1. Anyone wanting to add it, go ahead.
711 */
712 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
713 return -EPROTONOSUPPORT;
714 if (sa->sat_addr.s_node == ATADDR_BCAST ||
715 sa->sat_addr.s_node == 254)
716 return -EINVAL;
717 if (atif) {
718 /* Already setting address */
719 if (atif->status & ATIF_PROBE)
720 return -EBUSY;
721
722 atif->address.s_net = sa->sat_addr.s_net;
723 atif->address.s_node = sa->sat_addr.s_node;
724 atrtr_device_down(dev); /* Flush old routes */
725 } else {
726 atif = atif_add_device(dev, &sa->sat_addr);
727 if (!atif)
728 return -ENOMEM;
729 }
730 atif->nets = *nr;
731
732 /*
733 * Check if the chosen address is used. If so we
734 * error and atalkd will try another.
735 */
736
737 if (!(dev->flags & IFF_LOOPBACK) &&
738 !(dev->flags & IFF_POINTOPOINT) &&
739 atif_probe_device(atif) < 0) {
740 atif_drop_device(dev);
741 return -EADDRINUSE;
742 }
743
744 /* Hey it worked - add the direct routes */
745 sa = (struct sockaddr_at *)&rtdef.rt_gateway;
746 sa->sat_family = AF_APPLETALK;
747 sa->sat_addr.s_net = atif->address.s_net;
748 sa->sat_addr.s_node = atif->address.s_node;
749 sa = (struct sockaddr_at *)&rtdef.rt_dst;
750 rtdef.rt_flags = RTF_UP;
751 sa->sat_family = AF_APPLETALK;
752 sa->sat_addr.s_node = ATADDR_ANYNODE;
753 if (dev->flags & IFF_LOOPBACK ||
754 dev->flags & IFF_POINTOPOINT)
755 rtdef.rt_flags |= RTF_HOST;
756
757 /* Routerless initial state */
758 if (nr->nr_firstnet == htons(0) &&
759 nr->nr_lastnet == htons(0xFFFE)) {
760 sa->sat_addr.s_net = atif->address.s_net;
761 atrtr_create(&rtdef, dev);
762 atrtr_set_default(dev);
763 } else {
764 limit = ntohs(nr->nr_lastnet);
765 if (limit - ntohs(nr->nr_firstnet) > 4096) {
766 printk(KERN_WARNING "Too many routes/"
767 "iface.\n");
768 return -EINVAL;
769 }
770 if (add_route)
771 for (ct = ntohs(nr->nr_firstnet);
772 ct <= limit; ct++) {
773 sa->sat_addr.s_net = htons(ct);
774 atrtr_create(&rtdef, dev);
775 }
776 }
777 dev_mc_add_global(dev, aarp_mcast);
778 return 0;
779
780 case SIOCGIFADDR:
781 if (!atif)
782 return -EADDRNOTAVAIL;
783
784 sa->sat_family = AF_APPLETALK;
785 sa->sat_addr = atif->address;
786 break;
787
788 case SIOCGIFBRDADDR:
789 if (!atif)
790 return -EADDRNOTAVAIL;
791
792 sa->sat_family = AF_APPLETALK;
793 sa->sat_addr.s_net = atif->address.s_net;
794 sa->sat_addr.s_node = ATADDR_BCAST;
795 break;
796
797 case SIOCATALKDIFADDR:
798 case SIOCDIFADDR:
799 if (!capable(CAP_NET_ADMIN))
800 return -EPERM;
801 if (sa->sat_family != AF_APPLETALK)
802 return -EINVAL;
803 atalk_dev_down(dev);
804 break;
805
806 case SIOCSARP:
807 if (!capable(CAP_NET_ADMIN))
808 return -EPERM;
809 if (sa->sat_family != AF_APPLETALK)
810 return -EINVAL;
811 /*
812 * for now, we only support proxy AARP on ELAP;
813 * we should be able to do it for LocalTalk, too.
814 */
815 if (dev->type != ARPHRD_ETHER)
816 return -EPROTONOSUPPORT;
817
818 /*
819 * atif points to the current interface on this network;
820 * we aren't concerned about its current status (at
821 * least for now), but it has all the settings about
822 * the network we're going to probe. Consequently, it
823 * must exist.
824 */
825 if (!atif)
826 return -EADDRNOTAVAIL;
827
828 nr = (struct atalk_netrange *)&(atif->nets);
829 /*
830 * Phase 1 is fine on Localtalk but we don't do
831 * Ethertalk phase 1. Anyone wanting to add it, go ahead.
832 */
833 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
834 return -EPROTONOSUPPORT;
835
836 if (sa->sat_addr.s_node == ATADDR_BCAST ||
837 sa->sat_addr.s_node == 254)
838 return -EINVAL;
839
840 /*
841 * Check if the chosen address is used. If so we
842 * error and ATCP will try another.
843 */
844 if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
845 return -EADDRINUSE;
846
847 /*
848 * We now have an address on the local network, and
849 * the AARP code will defend it for us until we take it
850 * down. We don't set up any routes right now, because
851 * ATCP will install them manually via SIOCADDRT.
852 */
853 break;
854
855 case SIOCDARP:
856 if (!capable(CAP_NET_ADMIN))
857 return -EPERM;
858 if (sa->sat_family != AF_APPLETALK)
859 return -EINVAL;
860 if (!atif)
861 return -EADDRNOTAVAIL;
862
863 /* give to aarp module to remove proxy entry */
864 aarp_proxy_remove(atif->dev, &(sa->sat_addr));
865 return 0;
866 }
867
868 return put_user_ifreq(&atreq, arg);
869 }
870
atrtr_ioctl_addrt(struct rtentry * rt)871 static int atrtr_ioctl_addrt(struct rtentry *rt)
872 {
873 struct net_device *dev = NULL;
874
875 if (rt->rt_dev) {
876 char name[IFNAMSIZ];
877
878 if (copy_from_user(name, rt->rt_dev, IFNAMSIZ-1))
879 return -EFAULT;
880 name[IFNAMSIZ-1] = '\0';
881
882 dev = __dev_get_by_name(&init_net, name);
883 if (!dev)
884 return -ENODEV;
885 }
886 return atrtr_create(rt, dev);
887 }
888
889 /* Routing ioctl() calls */
atrtr_ioctl(unsigned int cmd,void __user * arg)890 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
891 {
892 struct rtentry rt;
893
894 if (copy_from_user(&rt, arg, sizeof(rt)))
895 return -EFAULT;
896
897 switch (cmd) {
898 case SIOCDELRT:
899 if (rt.rt_dst.sa_family != AF_APPLETALK)
900 return -EINVAL;
901 return atrtr_delete(&((struct sockaddr_at *)
902 &rt.rt_dst)->sat_addr);
903
904 case SIOCADDRT:
905 return atrtr_ioctl_addrt(&rt);
906 }
907 return -EINVAL;
908 }
909
910 /**************************************************************************\
911 * *
912 * Handling for system calls applied via the various interfaces to an *
913 * AppleTalk socket object. *
914 * *
915 \**************************************************************************/
916
917 /*
918 * Checksum: This is 'optional'. It's quite likely also a good
919 * candidate for assembler hackery 8)
920 */
atalk_sum_partial(const unsigned char * data,int len,unsigned long sum)921 static unsigned long atalk_sum_partial(const unsigned char *data,
922 int len, unsigned long sum)
923 {
924 /* This ought to be unwrapped neatly. I'll trust gcc for now */
925 while (len--) {
926 sum += *data++;
927 sum = rol16(sum, 1);
928 }
929 return sum;
930 }
931
932 /* Checksum skb data -- similar to skb_checksum */
atalk_sum_skb(const struct sk_buff * skb,int offset,int len,unsigned long sum)933 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
934 int len, unsigned long sum)
935 {
936 int start = skb_headlen(skb);
937 struct sk_buff *frag_iter;
938 int i, copy;
939
940 /* checksum stuff in header space */
941 if ((copy = start - offset) > 0) {
942 if (copy > len)
943 copy = len;
944 sum = atalk_sum_partial(skb->data + offset, copy, sum);
945 if ((len -= copy) == 0)
946 return sum;
947
948 offset += copy;
949 }
950
951 /* checksum stuff in frags */
952 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
953 int end;
954 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
955 WARN_ON(start > offset + len);
956
957 end = start + skb_frag_size(frag);
958 if ((copy = end - offset) > 0) {
959 u8 *vaddr;
960
961 if (copy > len)
962 copy = len;
963 vaddr = kmap_atomic(skb_frag_page(frag));
964 sum = atalk_sum_partial(vaddr + skb_frag_off(frag) +
965 offset - start, copy, sum);
966 kunmap_atomic(vaddr);
967
968 if (!(len -= copy))
969 return sum;
970 offset += copy;
971 }
972 start = end;
973 }
974
975 skb_walk_frags(skb, frag_iter) {
976 int end;
977
978 WARN_ON(start > offset + len);
979
980 end = start + frag_iter->len;
981 if ((copy = end - offset) > 0) {
982 if (copy > len)
983 copy = len;
984 sum = atalk_sum_skb(frag_iter, offset - start,
985 copy, sum);
986 if ((len -= copy) == 0)
987 return sum;
988 offset += copy;
989 }
990 start = end;
991 }
992
993 BUG_ON(len > 0);
994
995 return sum;
996 }
997
atalk_checksum(const struct sk_buff * skb,int len)998 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
999 {
1000 unsigned long sum;
1001
1002 /* skip header 4 bytes */
1003 sum = atalk_sum_skb(skb, 4, len-4, 0);
1004
1005 /* Use 0xFFFF for 0. 0 itself means none */
1006 return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1007 }
1008
1009 static struct proto ddp_proto = {
1010 .name = "DDP",
1011 .owner = THIS_MODULE,
1012 .obj_size = sizeof(struct atalk_sock),
1013 };
1014
1015 /*
1016 * Create a socket. Initialise the socket, blank the addresses
1017 * set the state.
1018 */
atalk_create(struct net * net,struct socket * sock,int protocol,int kern)1019 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1020 int kern)
1021 {
1022 struct sock *sk;
1023 int rc = -ESOCKTNOSUPPORT;
1024
1025 if (!net_eq(net, &init_net))
1026 return -EAFNOSUPPORT;
1027
1028 /*
1029 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1030 * and gives you the full ELAP frame. Should be handy for CAP 8)
1031 */
1032 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1033 goto out;
1034
1035 rc = -EPERM;
1036 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1037 goto out;
1038
1039 rc = -ENOMEM;
1040 sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, kern);
1041 if (!sk)
1042 goto out;
1043 rc = 0;
1044 sock->ops = &atalk_dgram_ops;
1045 sock_init_data(sock, sk);
1046
1047 /* Checksums on by default */
1048 sock_set_flag(sk, SOCK_ZAPPED);
1049 out:
1050 return rc;
1051 }
1052
1053 /* Free a socket. No work needed */
atalk_release(struct socket * sock)1054 static int atalk_release(struct socket *sock)
1055 {
1056 struct sock *sk = sock->sk;
1057
1058 if (sk) {
1059 sock_hold(sk);
1060 lock_sock(sk);
1061
1062 sock_orphan(sk);
1063 sock->sk = NULL;
1064 atalk_destroy_socket(sk);
1065
1066 release_sock(sk);
1067 sock_put(sk);
1068 }
1069 return 0;
1070 }
1071
1072 /**
1073 * atalk_pick_and_bind_port - Pick a source port when one is not given
1074 * @sk: socket to insert into the tables
1075 * @sat: address to search for
1076 *
1077 * Pick a source port when one is not given. If we can find a suitable free
1078 * one, we insert the socket into the tables using it.
1079 *
1080 * This whole operation must be atomic.
1081 */
atalk_pick_and_bind_port(struct sock * sk,struct sockaddr_at * sat)1082 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1083 {
1084 int retval;
1085
1086 write_lock_bh(&atalk_sockets_lock);
1087
1088 for (sat->sat_port = ATPORT_RESERVED;
1089 sat->sat_port < ATPORT_LAST;
1090 sat->sat_port++) {
1091 struct sock *s;
1092
1093 sk_for_each(s, &atalk_sockets) {
1094 struct atalk_sock *at = at_sk(s);
1095
1096 if (at->src_net == sat->sat_addr.s_net &&
1097 at->src_node == sat->sat_addr.s_node &&
1098 at->src_port == sat->sat_port)
1099 goto try_next_port;
1100 }
1101
1102 /* Wheee, it's free, assign and insert. */
1103 __atalk_insert_socket(sk);
1104 at_sk(sk)->src_port = sat->sat_port;
1105 retval = 0;
1106 goto out;
1107
1108 try_next_port:;
1109 }
1110
1111 retval = -EBUSY;
1112 out:
1113 write_unlock_bh(&atalk_sockets_lock);
1114 return retval;
1115 }
1116
atalk_autobind(struct sock * sk)1117 static int atalk_autobind(struct sock *sk)
1118 {
1119 struct atalk_sock *at = at_sk(sk);
1120 struct sockaddr_at sat;
1121 struct atalk_addr *ap = atalk_find_primary();
1122 int n = -EADDRNOTAVAIL;
1123
1124 if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1125 goto out;
1126
1127 at->src_net = sat.sat_addr.s_net = ap->s_net;
1128 at->src_node = sat.sat_addr.s_node = ap->s_node;
1129
1130 n = atalk_pick_and_bind_port(sk, &sat);
1131 if (!n)
1132 sock_reset_flag(sk, SOCK_ZAPPED);
1133 out:
1134 return n;
1135 }
1136
1137 /* Set the address 'our end' of the connection */
atalk_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)1138 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1139 {
1140 struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1141 struct sock *sk = sock->sk;
1142 struct atalk_sock *at = at_sk(sk);
1143 int err;
1144
1145 if (!sock_flag(sk, SOCK_ZAPPED) ||
1146 addr_len != sizeof(struct sockaddr_at))
1147 return -EINVAL;
1148
1149 if (addr->sat_family != AF_APPLETALK)
1150 return -EAFNOSUPPORT;
1151
1152 lock_sock(sk);
1153 if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1154 struct atalk_addr *ap = atalk_find_primary();
1155
1156 err = -EADDRNOTAVAIL;
1157 if (!ap)
1158 goto out;
1159
1160 at->src_net = addr->sat_addr.s_net = ap->s_net;
1161 at->src_node = addr->sat_addr.s_node = ap->s_node;
1162 } else {
1163 err = -EADDRNOTAVAIL;
1164 if (!atalk_find_interface(addr->sat_addr.s_net,
1165 addr->sat_addr.s_node))
1166 goto out;
1167
1168 at->src_net = addr->sat_addr.s_net;
1169 at->src_node = addr->sat_addr.s_node;
1170 }
1171
1172 if (addr->sat_port == ATADDR_ANYPORT) {
1173 err = atalk_pick_and_bind_port(sk, addr);
1174
1175 if (err < 0)
1176 goto out;
1177 } else {
1178 at->src_port = addr->sat_port;
1179
1180 err = -EADDRINUSE;
1181 if (atalk_find_or_insert_socket(sk, addr))
1182 goto out;
1183 }
1184
1185 sock_reset_flag(sk, SOCK_ZAPPED);
1186 err = 0;
1187 out:
1188 release_sock(sk);
1189 return err;
1190 }
1191
1192 /* Set the address we talk to */
atalk_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)1193 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1194 int addr_len, int flags)
1195 {
1196 struct sock *sk = sock->sk;
1197 struct atalk_sock *at = at_sk(sk);
1198 struct sockaddr_at *addr;
1199 int err;
1200
1201 sk->sk_state = TCP_CLOSE;
1202 sock->state = SS_UNCONNECTED;
1203
1204 if (addr_len != sizeof(*addr))
1205 return -EINVAL;
1206
1207 addr = (struct sockaddr_at *)uaddr;
1208
1209 if (addr->sat_family != AF_APPLETALK)
1210 return -EAFNOSUPPORT;
1211
1212 if (addr->sat_addr.s_node == ATADDR_BCAST &&
1213 !sock_flag(sk, SOCK_BROADCAST)) {
1214 #if 1
1215 pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
1216 current->comm);
1217 #else
1218 return -EACCES;
1219 #endif
1220 }
1221
1222 lock_sock(sk);
1223 err = -EBUSY;
1224 if (sock_flag(sk, SOCK_ZAPPED))
1225 if (atalk_autobind(sk) < 0)
1226 goto out;
1227
1228 err = -ENETUNREACH;
1229 if (!atrtr_get_dev(&addr->sat_addr))
1230 goto out;
1231
1232 at->dest_port = addr->sat_port;
1233 at->dest_net = addr->sat_addr.s_net;
1234 at->dest_node = addr->sat_addr.s_node;
1235
1236 sock->state = SS_CONNECTED;
1237 sk->sk_state = TCP_ESTABLISHED;
1238 err = 0;
1239 out:
1240 release_sock(sk);
1241 return err;
1242 }
1243
1244 /*
1245 * Find the name of an AppleTalk socket. Just copy the right
1246 * fields into the sockaddr.
1247 */
atalk_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1248 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1249 int peer)
1250 {
1251 struct sockaddr_at sat;
1252 struct sock *sk = sock->sk;
1253 struct atalk_sock *at = at_sk(sk);
1254 int err;
1255
1256 lock_sock(sk);
1257 err = -ENOBUFS;
1258 if (sock_flag(sk, SOCK_ZAPPED))
1259 if (atalk_autobind(sk) < 0)
1260 goto out;
1261
1262 memset(&sat, 0, sizeof(sat));
1263
1264 if (peer) {
1265 err = -ENOTCONN;
1266 if (sk->sk_state != TCP_ESTABLISHED)
1267 goto out;
1268
1269 sat.sat_addr.s_net = at->dest_net;
1270 sat.sat_addr.s_node = at->dest_node;
1271 sat.sat_port = at->dest_port;
1272 } else {
1273 sat.sat_addr.s_net = at->src_net;
1274 sat.sat_addr.s_node = at->src_node;
1275 sat.sat_port = at->src_port;
1276 }
1277
1278 sat.sat_family = AF_APPLETALK;
1279 memcpy(uaddr, &sat, sizeof(sat));
1280 err = sizeof(struct sockaddr_at);
1281
1282 out:
1283 release_sock(sk);
1284 return err;
1285 }
1286
1287 #if IS_ENABLED(CONFIG_IPDDP)
is_ip_over_ddp(struct sk_buff * skb)1288 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1289 {
1290 return skb->data[12] == 22;
1291 }
1292
handle_ip_over_ddp(struct sk_buff * skb)1293 static int handle_ip_over_ddp(struct sk_buff *skb)
1294 {
1295 struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1296 struct net_device_stats *stats;
1297
1298 /* This needs to be able to handle ipddp"N" devices */
1299 if (!dev) {
1300 kfree_skb(skb);
1301 return NET_RX_DROP;
1302 }
1303
1304 skb->protocol = htons(ETH_P_IP);
1305 skb_pull(skb, 13);
1306 skb->dev = dev;
1307 skb_reset_transport_header(skb);
1308
1309 stats = netdev_priv(dev);
1310 stats->rx_packets++;
1311 stats->rx_bytes += skb->len + 13;
1312 return netif_rx(skb); /* Send the SKB up to a higher place. */
1313 }
1314 #else
1315 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1316 #define is_ip_over_ddp(skb) 0
1317 #define handle_ip_over_ddp(skb) 0
1318 #endif
1319
atalk_route_packet(struct sk_buff * skb,struct net_device * dev,struct ddpehdr * ddp,__u16 len_hops,int origlen)1320 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1321 struct ddpehdr *ddp, __u16 len_hops, int origlen)
1322 {
1323 struct atalk_route *rt;
1324 struct atalk_addr ta;
1325
1326 /*
1327 * Don't route multicast, etc., packets, or packets sent to "this
1328 * network"
1329 */
1330 if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1331 /*
1332 * FIXME:
1333 *
1334 * Can it ever happen that a packet is from a PPP iface and
1335 * needs to be broadcast onto the default network?
1336 */
1337 if (dev->type == ARPHRD_PPP)
1338 printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1339 "packet received from PPP iface\n");
1340 goto free_it;
1341 }
1342
1343 ta.s_net = ddp->deh_dnet;
1344 ta.s_node = ddp->deh_dnode;
1345
1346 /* Route the packet */
1347 rt = atrtr_find(&ta);
1348 /* increment hops count */
1349 len_hops += 1 << 10;
1350 if (!rt || !(len_hops & (15 << 10)))
1351 goto free_it;
1352
1353 /* FIXME: use skb->cb to be able to use shared skbs */
1354
1355 /*
1356 * Route goes through another gateway, so set the target to the
1357 * gateway instead.
1358 */
1359
1360 if (rt->flags & RTF_GATEWAY) {
1361 ta.s_net = rt->gateway.s_net;
1362 ta.s_node = rt->gateway.s_node;
1363 }
1364
1365 /* Fix up skb->len field */
1366 skb_trim(skb, min_t(unsigned int, origlen,
1367 (rt->dev->hard_header_len +
1368 ddp_dl->header_length + (len_hops & 1023))));
1369
1370 /* FIXME: use skb->cb to be able to use shared skbs */
1371 ddp->deh_len_hops = htons(len_hops);
1372
1373 /*
1374 * Send the buffer onwards
1375 *
1376 * Now we must always be careful. If it's come from LocalTalk to
1377 * EtherTalk it might not fit
1378 *
1379 * Order matters here: If a packet has to be copied to make a new
1380 * headroom (rare hopefully) then it won't need unsharing.
1381 *
1382 * Note. ddp-> becomes invalid at the realloc.
1383 */
1384 if (skb_headroom(skb) < 22) {
1385 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1386 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1387 kfree_skb(skb);
1388 skb = nskb;
1389 } else
1390 skb = skb_unshare(skb, GFP_ATOMIC);
1391
1392 /*
1393 * If the buffer didn't vanish into the lack of space bitbucket we can
1394 * send it.
1395 */
1396 if (skb == NULL)
1397 goto drop;
1398
1399 if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1400 return NET_RX_DROP;
1401 return NET_RX_SUCCESS;
1402 free_it:
1403 kfree_skb(skb);
1404 drop:
1405 return NET_RX_DROP;
1406 }
1407
1408 /**
1409 * atalk_rcv - Receive a packet (in skb) from device dev
1410 * @skb: packet received
1411 * @dev: network device where the packet comes from
1412 * @pt: packet type
1413 * @orig_dev: the original receive net device
1414 *
1415 * Receive a packet (in skb) from device dev. This has come from the SNAP
1416 * decoder, and on entry skb->transport_header is the DDP header, skb->len
1417 * is the DDP header, skb->len is the DDP length. The physical headers
1418 * have been extracted. PPP should probably pass frames marked as for this
1419 * layer. [ie ARPHRD_ETHERTALK]
1420 */
atalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1421 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1422 struct packet_type *pt, struct net_device *orig_dev)
1423 {
1424 struct ddpehdr *ddp;
1425 struct sock *sock;
1426 struct atalk_iface *atif;
1427 struct sockaddr_at tosat;
1428 int origlen;
1429 __u16 len_hops;
1430
1431 if (!net_eq(dev_net(dev), &init_net))
1432 goto drop;
1433
1434 /* Don't mangle buffer if shared */
1435 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1436 goto out;
1437
1438 /* Size check and make sure header is contiguous */
1439 if (!pskb_may_pull(skb, sizeof(*ddp)))
1440 goto drop;
1441
1442 ddp = ddp_hdr(skb);
1443
1444 len_hops = ntohs(ddp->deh_len_hops);
1445
1446 /* Trim buffer in case of stray trailing data */
1447 origlen = skb->len;
1448 skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1449
1450 /*
1451 * Size check to see if ddp->deh_len was crap
1452 * (Otherwise we'll detonate most spectacularly
1453 * in the middle of atalk_checksum() or recvmsg()).
1454 */
1455 if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1456 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1457 "skb->len=%u)\n", len_hops & 1023, skb->len);
1458 goto drop;
1459 }
1460
1461 /*
1462 * Any checksums. Note we don't do htons() on this == is assumed to be
1463 * valid for net byte orders all over the networking code...
1464 */
1465 if (ddp->deh_sum &&
1466 atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1467 /* Not a valid AppleTalk frame - dustbin time */
1468 goto drop;
1469
1470 /* Check the packet is aimed at us */
1471 if (!ddp->deh_dnet) /* Net 0 is 'this network' */
1472 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1473 else
1474 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1475
1476 if (!atif) {
1477 /* Not ours, so we route the packet via the correct
1478 * AppleTalk iface
1479 */
1480 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1481 }
1482
1483 /* if IP over DDP is not selected this code will be optimized out */
1484 if (is_ip_over_ddp(skb))
1485 return handle_ip_over_ddp(skb);
1486 /*
1487 * Which socket - atalk_search_socket() looks for a *full match*
1488 * of the <net, node, port> tuple.
1489 */
1490 tosat.sat_addr.s_net = ddp->deh_dnet;
1491 tosat.sat_addr.s_node = ddp->deh_dnode;
1492 tosat.sat_port = ddp->deh_dport;
1493
1494 sock = atalk_search_socket(&tosat, atif);
1495 if (!sock) /* But not one of our sockets */
1496 goto drop;
1497
1498 /* Queue packet (standard) */
1499 if (sock_queue_rcv_skb(sock, skb) < 0)
1500 goto drop;
1501
1502 return NET_RX_SUCCESS;
1503
1504 drop:
1505 kfree_skb(skb);
1506 out:
1507 return NET_RX_DROP;
1508
1509 }
1510
1511 /*
1512 * Receive a LocalTalk frame. We make some demands on the caller here.
1513 * Caller must provide enough headroom on the packet to pull the short
1514 * header and append a long one.
1515 */
ltalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1516 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1517 struct packet_type *pt, struct net_device *orig_dev)
1518 {
1519 if (!net_eq(dev_net(dev), &init_net))
1520 goto freeit;
1521
1522 /* Expand any short form frames */
1523 if (skb_mac_header(skb)[2] == 1) {
1524 struct ddpehdr *ddp;
1525 /* Find our address */
1526 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1527
1528 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1529 goto freeit;
1530
1531 /* Don't mangle buffer if shared */
1532 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1533 return 0;
1534
1535 /*
1536 * The push leaves us with a ddephdr not an shdr, and
1537 * handily the port bytes in the right place preset.
1538 */
1539 ddp = skb_push(skb, sizeof(*ddp) - 4);
1540
1541 /* Now fill in the long header */
1542
1543 /*
1544 * These two first. The mac overlays the new source/dest
1545 * network information so we MUST copy these before
1546 * we write the network numbers !
1547 */
1548
1549 ddp->deh_dnode = skb_mac_header(skb)[0]; /* From physical header */
1550 ddp->deh_snode = skb_mac_header(skb)[1]; /* From physical header */
1551
1552 ddp->deh_dnet = ap->s_net; /* Network number */
1553 ddp->deh_snet = ap->s_net;
1554 ddp->deh_sum = 0; /* No checksum */
1555 /*
1556 * Not sure about this bit...
1557 */
1558 /* Non routable, so force a drop if we slip up later */
1559 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1560 }
1561 skb_reset_transport_header(skb);
1562
1563 return atalk_rcv(skb, dev, pt, orig_dev);
1564 freeit:
1565 kfree_skb(skb);
1566 return 0;
1567 }
1568
atalk_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)1569 static int atalk_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1570 {
1571 struct sock *sk = sock->sk;
1572 struct atalk_sock *at = at_sk(sk);
1573 DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
1574 int flags = msg->msg_flags;
1575 int loopback = 0;
1576 struct sockaddr_at local_satalk, gsat;
1577 struct sk_buff *skb;
1578 struct net_device *dev;
1579 struct ddpehdr *ddp;
1580 int size, hard_header_len;
1581 struct atalk_route *rt, *rt_lo = NULL;
1582 int err;
1583
1584 if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1585 return -EINVAL;
1586
1587 if (len > DDP_MAXSZ)
1588 return -EMSGSIZE;
1589
1590 lock_sock(sk);
1591 if (usat) {
1592 err = -EBUSY;
1593 if (sock_flag(sk, SOCK_ZAPPED))
1594 if (atalk_autobind(sk) < 0)
1595 goto out;
1596
1597 err = -EINVAL;
1598 if (msg->msg_namelen < sizeof(*usat) ||
1599 usat->sat_family != AF_APPLETALK)
1600 goto out;
1601
1602 err = -EPERM;
1603 /* netatalk didn't implement this check */
1604 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1605 !sock_flag(sk, SOCK_BROADCAST)) {
1606 goto out;
1607 }
1608 } else {
1609 err = -ENOTCONN;
1610 if (sk->sk_state != TCP_ESTABLISHED)
1611 goto out;
1612 usat = &local_satalk;
1613 usat->sat_family = AF_APPLETALK;
1614 usat->sat_port = at->dest_port;
1615 usat->sat_addr.s_node = at->dest_node;
1616 usat->sat_addr.s_net = at->dest_net;
1617 }
1618
1619 /* Build a packet */
1620 SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1621
1622 /* For headers */
1623 size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1624
1625 if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1626 rt = atrtr_find(&usat->sat_addr);
1627 } else {
1628 struct atalk_addr at_hint;
1629
1630 at_hint.s_node = 0;
1631 at_hint.s_net = at->src_net;
1632
1633 rt = atrtr_find(&at_hint);
1634 }
1635 err = -ENETUNREACH;
1636 if (!rt)
1637 goto out;
1638
1639 dev = rt->dev;
1640
1641 SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1642 sk, size, dev->name);
1643
1644 hard_header_len = dev->hard_header_len;
1645 /* Leave room for loopback hardware header if necessary */
1646 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1647 (dev->flags & IFF_LOOPBACK || !(rt->flags & RTF_GATEWAY))) {
1648 struct atalk_addr at_lo;
1649
1650 at_lo.s_node = 0;
1651 at_lo.s_net = 0;
1652
1653 rt_lo = atrtr_find(&at_lo);
1654
1655 if (rt_lo && rt_lo->dev->hard_header_len > hard_header_len)
1656 hard_header_len = rt_lo->dev->hard_header_len;
1657 }
1658
1659 size += hard_header_len;
1660 release_sock(sk);
1661 skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1662 lock_sock(sk);
1663 if (!skb)
1664 goto out;
1665
1666 skb_reserve(skb, ddp_dl->header_length);
1667 skb_reserve(skb, hard_header_len);
1668 skb->dev = dev;
1669
1670 SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1671
1672 ddp = skb_put(skb, sizeof(struct ddpehdr));
1673 ddp->deh_len_hops = htons(len + sizeof(*ddp));
1674 ddp->deh_dnet = usat->sat_addr.s_net;
1675 ddp->deh_snet = at->src_net;
1676 ddp->deh_dnode = usat->sat_addr.s_node;
1677 ddp->deh_snode = at->src_node;
1678 ddp->deh_dport = usat->sat_port;
1679 ddp->deh_sport = at->src_port;
1680
1681 SOCK_DEBUG(sk, "SK %p: Copy user data (%zd bytes).\n", sk, len);
1682
1683 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1684 if (err) {
1685 kfree_skb(skb);
1686 err = -EFAULT;
1687 goto out;
1688 }
1689
1690 if (sk->sk_no_check_tx)
1691 ddp->deh_sum = 0;
1692 else
1693 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1694
1695 /*
1696 * Loopback broadcast packets to non gateway targets (ie routes
1697 * to group we are in)
1698 */
1699 if (ddp->deh_dnode == ATADDR_BCAST &&
1700 !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1701 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1702
1703 if (skb2) {
1704 loopback = 1;
1705 SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1706 /*
1707 * If it fails it is queued/sent above in the aarp queue
1708 */
1709 aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1710 }
1711 }
1712
1713 if (dev->flags & IFF_LOOPBACK || loopback) {
1714 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1715 /* loop back */
1716 skb_orphan(skb);
1717 if (ddp->deh_dnode == ATADDR_BCAST) {
1718 if (!rt_lo) {
1719 kfree_skb(skb);
1720 err = -ENETUNREACH;
1721 goto out;
1722 }
1723 dev = rt_lo->dev;
1724 skb->dev = dev;
1725 }
1726 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1727 } else {
1728 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1729 if (rt->flags & RTF_GATEWAY) {
1730 gsat.sat_addr = rt->gateway;
1731 usat = &gsat;
1732 }
1733
1734 /*
1735 * If it fails it is queued/sent above in the aarp queue
1736 */
1737 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1738 }
1739 SOCK_DEBUG(sk, "SK %p: Done write (%zd).\n", sk, len);
1740
1741 out:
1742 release_sock(sk);
1743 return err ? : len;
1744 }
1745
atalk_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1746 static int atalk_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1747 int flags)
1748 {
1749 struct sock *sk = sock->sk;
1750 struct ddpehdr *ddp;
1751 int copied = 0;
1752 int offset = 0;
1753 int err = 0;
1754 struct sk_buff *skb;
1755
1756 skb = skb_recv_datagram(sk, flags, &err);
1757 lock_sock(sk);
1758
1759 if (!skb)
1760 goto out;
1761
1762 /* FIXME: use skb->cb to be able to use shared skbs */
1763 ddp = ddp_hdr(skb);
1764 copied = ntohs(ddp->deh_len_hops) & 1023;
1765
1766 if (sk->sk_type != SOCK_RAW) {
1767 offset = sizeof(*ddp);
1768 copied -= offset;
1769 }
1770
1771 if (copied > size) {
1772 copied = size;
1773 msg->msg_flags |= MSG_TRUNC;
1774 }
1775 err = skb_copy_datagram_msg(skb, offset, msg, copied);
1776
1777 if (!err && msg->msg_name) {
1778 DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
1779 sat->sat_family = AF_APPLETALK;
1780 sat->sat_port = ddp->deh_sport;
1781 sat->sat_addr.s_node = ddp->deh_snode;
1782 sat->sat_addr.s_net = ddp->deh_snet;
1783 msg->msg_namelen = sizeof(*sat);
1784 }
1785
1786 skb_free_datagram(sk, skb); /* Free the datagram. */
1787
1788 out:
1789 release_sock(sk);
1790 return err ? : copied;
1791 }
1792
1793
1794 /*
1795 * AppleTalk ioctl calls.
1796 */
atalk_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1797 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1798 {
1799 int rc = -ENOIOCTLCMD;
1800 struct sock *sk = sock->sk;
1801 void __user *argp = (void __user *)arg;
1802
1803 switch (cmd) {
1804 /* Protocol layer */
1805 case TIOCOUTQ: {
1806 long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1807
1808 if (amount < 0)
1809 amount = 0;
1810 rc = put_user(amount, (int __user *)argp);
1811 break;
1812 }
1813 case TIOCINQ: {
1814 struct sk_buff *skb;
1815 long amount = 0;
1816
1817 spin_lock_irq(&sk->sk_receive_queue.lock);
1818 skb = skb_peek(&sk->sk_receive_queue);
1819 if (skb)
1820 amount = skb->len - sizeof(struct ddpehdr);
1821 spin_unlock_irq(&sk->sk_receive_queue.lock);
1822 rc = put_user(amount, (int __user *)argp);
1823 break;
1824 }
1825 /* Routing */
1826 case SIOCADDRT:
1827 case SIOCDELRT:
1828 rc = -EPERM;
1829 if (capable(CAP_NET_ADMIN))
1830 rc = atrtr_ioctl(cmd, argp);
1831 break;
1832 /* Interface */
1833 case SIOCGIFADDR:
1834 case SIOCSIFADDR:
1835 case SIOCGIFBRDADDR:
1836 case SIOCATALKDIFADDR:
1837 case SIOCDIFADDR:
1838 case SIOCSARP: /* proxy AARP */
1839 case SIOCDARP: /* proxy AARP */
1840 rtnl_lock();
1841 rc = atif_ioctl(cmd, argp);
1842 rtnl_unlock();
1843 break;
1844 }
1845
1846 return rc;
1847 }
1848
1849
1850 #ifdef CONFIG_COMPAT
atalk_compat_routing_ioctl(struct sock * sk,unsigned int cmd,struct compat_rtentry __user * ur)1851 static int atalk_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1852 struct compat_rtentry __user *ur)
1853 {
1854 compat_uptr_t rtdev;
1855 struct rtentry rt;
1856
1857 if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1858 3 * sizeof(struct sockaddr)) ||
1859 get_user(rt.rt_flags, &ur->rt_flags) ||
1860 get_user(rt.rt_metric, &ur->rt_metric) ||
1861 get_user(rt.rt_mtu, &ur->rt_mtu) ||
1862 get_user(rt.rt_window, &ur->rt_window) ||
1863 get_user(rt.rt_irtt, &ur->rt_irtt) ||
1864 get_user(rtdev, &ur->rt_dev))
1865 return -EFAULT;
1866
1867 switch (cmd) {
1868 case SIOCDELRT:
1869 if (rt.rt_dst.sa_family != AF_APPLETALK)
1870 return -EINVAL;
1871 return atrtr_delete(&((struct sockaddr_at *)
1872 &rt.rt_dst)->sat_addr);
1873
1874 case SIOCADDRT:
1875 rt.rt_dev = compat_ptr(rtdev);
1876 return atrtr_ioctl_addrt(&rt);
1877 default:
1878 return -EINVAL;
1879 }
1880 }
atalk_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1881 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1882 {
1883 void __user *argp = compat_ptr(arg);
1884 struct sock *sk = sock->sk;
1885
1886 switch (cmd) {
1887 case SIOCADDRT:
1888 case SIOCDELRT:
1889 return atalk_compat_routing_ioctl(sk, cmd, argp);
1890 /*
1891 * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1892 * cannot handle it in common code. The data we access if ifreq
1893 * here is compatible, so we can simply call the native
1894 * handler.
1895 */
1896 case SIOCATALKDIFADDR:
1897 return atalk_ioctl(sock, cmd, (unsigned long)argp);
1898 default:
1899 return -ENOIOCTLCMD;
1900 }
1901 }
1902 #endif /* CONFIG_COMPAT */
1903
1904
1905 static const struct net_proto_family atalk_family_ops = {
1906 .family = PF_APPLETALK,
1907 .create = atalk_create,
1908 .owner = THIS_MODULE,
1909 };
1910
1911 static const struct proto_ops atalk_dgram_ops = {
1912 .family = PF_APPLETALK,
1913 .owner = THIS_MODULE,
1914 .release = atalk_release,
1915 .bind = atalk_bind,
1916 .connect = atalk_connect,
1917 .socketpair = sock_no_socketpair,
1918 .accept = sock_no_accept,
1919 .getname = atalk_getname,
1920 .poll = datagram_poll,
1921 .ioctl = atalk_ioctl,
1922 .gettstamp = sock_gettstamp,
1923 #ifdef CONFIG_COMPAT
1924 .compat_ioctl = atalk_compat_ioctl,
1925 #endif
1926 .listen = sock_no_listen,
1927 .shutdown = sock_no_shutdown,
1928 .sendmsg = atalk_sendmsg,
1929 .recvmsg = atalk_recvmsg,
1930 .mmap = sock_no_mmap,
1931 };
1932
1933 static struct notifier_block ddp_notifier = {
1934 .notifier_call = ddp_device_event,
1935 };
1936
1937 static struct packet_type ltalk_packet_type __read_mostly = {
1938 .type = cpu_to_be16(ETH_P_LOCALTALK),
1939 .func = ltalk_rcv,
1940 };
1941
1942 static struct packet_type ppptalk_packet_type __read_mostly = {
1943 .type = cpu_to_be16(ETH_P_PPPTALK),
1944 .func = atalk_rcv,
1945 };
1946
1947 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1948
1949 /* Export symbols for use by drivers when AppleTalk is a module */
1950 EXPORT_SYMBOL(atrtr_get_dev);
1951 EXPORT_SYMBOL(atalk_find_dev_addr);
1952
1953 /* Called by proto.c on kernel start up */
atalk_init(void)1954 static int __init atalk_init(void)
1955 {
1956 int rc;
1957
1958 rc = proto_register(&ddp_proto, 0);
1959 if (rc)
1960 goto out;
1961
1962 rc = sock_register(&atalk_family_ops);
1963 if (rc)
1964 goto out_proto;
1965
1966 ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1967 if (!ddp_dl) {
1968 pr_crit("Unable to register DDP with SNAP.\n");
1969 rc = -ENOMEM;
1970 goto out_sock;
1971 }
1972
1973 dev_add_pack(<alk_packet_type);
1974 dev_add_pack(&ppptalk_packet_type);
1975
1976 rc = register_netdevice_notifier(&ddp_notifier);
1977 if (rc)
1978 goto out_snap;
1979
1980 rc = aarp_proto_init();
1981 if (rc)
1982 goto out_dev;
1983
1984 rc = atalk_proc_init();
1985 if (rc)
1986 goto out_aarp;
1987
1988 rc = atalk_register_sysctl();
1989 if (rc)
1990 goto out_proc;
1991 out:
1992 return rc;
1993 out_proc:
1994 atalk_proc_exit();
1995 out_aarp:
1996 aarp_cleanup_module();
1997 out_dev:
1998 unregister_netdevice_notifier(&ddp_notifier);
1999 out_snap:
2000 dev_remove_pack(&ppptalk_packet_type);
2001 dev_remove_pack(<alk_packet_type);
2002 unregister_snap_client(ddp_dl);
2003 out_sock:
2004 sock_unregister(PF_APPLETALK);
2005 out_proto:
2006 proto_unregister(&ddp_proto);
2007 goto out;
2008 }
2009 module_init(atalk_init);
2010
2011 /*
2012 * No explicit module reference count manipulation is needed in the
2013 * protocol. Socket layer sets module reference count for us
2014 * and interfaces reference counting is done
2015 * by the network device layer.
2016 *
2017 * Ergo, before the AppleTalk module can be removed, all AppleTalk
2018 * sockets should be closed from user space.
2019 */
atalk_exit(void)2020 static void __exit atalk_exit(void)
2021 {
2022 #ifdef CONFIG_SYSCTL
2023 atalk_unregister_sysctl();
2024 #endif /* CONFIG_SYSCTL */
2025 atalk_proc_exit();
2026 aarp_cleanup_module(); /* General aarp clean-up. */
2027 unregister_netdevice_notifier(&ddp_notifier);
2028 dev_remove_pack(<alk_packet_type);
2029 dev_remove_pack(&ppptalk_packet_type);
2030 unregister_snap_client(ddp_dl);
2031 sock_unregister(PF_APPLETALK);
2032 proto_unregister(&ddp_proto);
2033 }
2034 module_exit(atalk_exit);
2035
2036 MODULE_LICENSE("GPL");
2037 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
2038 MODULE_DESCRIPTION("AppleTalk 0.20\n");
2039 MODULE_ALIAS_NETPROTO(PF_APPLETALK);
2040