1 /*
2 * DDP: An implementation of the AppleTalk DDP protocol for
3 * Ethernet 'ELAP'.
4 *
5 * Alan Cox <alan@lxorguk.ukuu.org.uk>
6 *
7 * With more than a little assistance from
8 *
9 * Wesley Craig <netatalk@umich.edu>
10 *
11 * Fixes:
12 * Neil Horman : Added missing device ioctls
13 * Michael Callahan : Made routing work
14 * Wesley Craig : Fix probing to listen to a
15 * passed node id.
16 * Alan Cox : Added send/recvmsg support
17 * Alan Cox : Moved at. to protinfo in
18 * socket.
19 * Alan Cox : Added firewall hooks.
20 * Alan Cox : Supports new ARPHRD_LOOPBACK
21 * Christer Weinigel : Routing and /proc fixes.
22 * Bradford Johnson : LocalTalk.
23 * Tom Dyas : Module support.
24 * Alan Cox : Hooks for PPP (based on the
25 * LocalTalk hook).
26 * Alan Cox : Posix bits
27 * Alan Cox/Mike Freeman : Possible fix to NBP problems
28 * Bradford Johnson : IP-over-DDP (experimental)
29 * Jay Schulist : Moved IP-over-DDP to its own
30 * driver file. (ipddp.c & ipddp.h)
31 * Jay Schulist : Made work as module with
32 * AppleTalk drivers, cleaned it.
33 * Rob Newberry : Added proxy AARP and AARP
34 * procfs, moved probing to AARP
35 * module.
36 * Adrian Sun/
37 * Michael Zuelsdorff : fix for net.0 packets. don't
38 * allow illegal ether/tokentalk
39 * port assignment. we lose a
40 * valid localtalk port as a
41 * result.
42 * Arnaldo C. de Melo : Cleanup, in preparation for
43 * shared skb support 8)
44 * Arnaldo C. de Melo : Move proc stuff to atalk_proc.c,
45 * use seq_file
46 *
47 * This program is free software; you can redistribute it and/or
48 * modify it under the terms of the GNU General Public License
49 * as published by the Free Software Foundation; either version
50 * 2 of the License, or (at your option) any later version.
51 *
52 */
53
54 #include <linux/capability.h>
55 #include <linux/module.h>
56 #include <linux/if_arp.h>
57 #include <linux/termios.h> /* For TIOCOUTQ/INQ */
58 #include <linux/compat.h>
59 #include <linux/slab.h>
60 #include <net/datalink.h>
61 #include <net/psnap.h>
62 #include <net/sock.h>
63 #include <net/tcp_states.h>
64 #include <net/route.h>
65 #include <linux/atalk.h>
66 #include "../core/kmap_skb.h"
67
68 struct datalink_proto *ddp_dl, *aarp_dl;
69 static const struct proto_ops atalk_dgram_ops;
70
71 /**************************************************************************\
72 * *
73 * Handlers for the socket list. *
74 * *
75 \**************************************************************************/
76
77 HLIST_HEAD(atalk_sockets);
78 DEFINE_RWLOCK(atalk_sockets_lock);
79
__atalk_insert_socket(struct sock * sk)80 static inline void __atalk_insert_socket(struct sock *sk)
81 {
82 sk_add_node(sk, &atalk_sockets);
83 }
84
atalk_remove_socket(struct sock * sk)85 static inline void atalk_remove_socket(struct sock *sk)
86 {
87 write_lock_bh(&atalk_sockets_lock);
88 sk_del_node_init(sk);
89 write_unlock_bh(&atalk_sockets_lock);
90 }
91
atalk_search_socket(struct sockaddr_at * to,struct atalk_iface * atif)92 static struct sock *atalk_search_socket(struct sockaddr_at *to,
93 struct atalk_iface *atif)
94 {
95 struct sock *s;
96 struct hlist_node *node;
97
98 read_lock_bh(&atalk_sockets_lock);
99 sk_for_each(s, node, &atalk_sockets) {
100 struct atalk_sock *at = at_sk(s);
101
102 if (to->sat_port != at->src_port)
103 continue;
104
105 if (to->sat_addr.s_net == ATADDR_ANYNET &&
106 to->sat_addr.s_node == ATADDR_BCAST)
107 goto found;
108
109 if (to->sat_addr.s_net == at->src_net &&
110 (to->sat_addr.s_node == at->src_node ||
111 to->sat_addr.s_node == ATADDR_BCAST ||
112 to->sat_addr.s_node == ATADDR_ANYNODE))
113 goto found;
114
115 /* XXXX.0 -- we got a request for this router. make sure
116 * that the node is appropriately set. */
117 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
118 to->sat_addr.s_net != ATADDR_ANYNET &&
119 atif->address.s_node == at->src_node) {
120 to->sat_addr.s_node = atif->address.s_node;
121 goto found;
122 }
123 }
124 s = NULL;
125 found:
126 read_unlock_bh(&atalk_sockets_lock);
127 return s;
128 }
129
130 /**
131 * atalk_find_or_insert_socket - Try to find a socket matching ADDR
132 * @sk - socket to insert in the list if it is not there already
133 * @sat - address to search for
134 *
135 * Try to find a socket matching ADDR in the socket list, if found then return
136 * it. If not, insert SK into the socket list.
137 *
138 * This entire operation must execute atomically.
139 */
atalk_find_or_insert_socket(struct sock * sk,struct sockaddr_at * sat)140 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
141 struct sockaddr_at *sat)
142 {
143 struct sock *s;
144 struct hlist_node *node;
145 struct atalk_sock *at;
146
147 write_lock_bh(&atalk_sockets_lock);
148 sk_for_each(s, node, &atalk_sockets) {
149 at = at_sk(s);
150
151 if (at->src_net == sat->sat_addr.s_net &&
152 at->src_node == sat->sat_addr.s_node &&
153 at->src_port == sat->sat_port)
154 goto found;
155 }
156 s = NULL;
157 __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
158 found:
159 write_unlock_bh(&atalk_sockets_lock);
160 return s;
161 }
162
atalk_destroy_timer(unsigned long data)163 static void atalk_destroy_timer(unsigned long data)
164 {
165 struct sock *sk = (struct sock *)data;
166
167 if (sk_has_allocations(sk)) {
168 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
169 add_timer(&sk->sk_timer);
170 } else
171 sock_put(sk);
172 }
173
atalk_destroy_socket(struct sock * sk)174 static inline void atalk_destroy_socket(struct sock *sk)
175 {
176 atalk_remove_socket(sk);
177 skb_queue_purge(&sk->sk_receive_queue);
178
179 if (sk_has_allocations(sk)) {
180 setup_timer(&sk->sk_timer, atalk_destroy_timer,
181 (unsigned long)sk);
182 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
183 add_timer(&sk->sk_timer);
184 } else
185 sock_put(sk);
186 }
187
188 /**************************************************************************\
189 * *
190 * Routing tables for the AppleTalk socket layer. *
191 * *
192 \**************************************************************************/
193
194 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
195 struct atalk_route *atalk_routes;
196 DEFINE_RWLOCK(atalk_routes_lock);
197
198 struct atalk_iface *atalk_interfaces;
199 DEFINE_RWLOCK(atalk_interfaces_lock);
200
201 /* For probing devices or in a routerless network */
202 struct atalk_route atrtr_default;
203
204 /* AppleTalk interface control */
205 /*
206 * Drop a device. Doesn't drop any of its routes - that is the caller's
207 * problem. Called when we down the interface or delete the address.
208 */
atif_drop_device(struct net_device * dev)209 static void atif_drop_device(struct net_device *dev)
210 {
211 struct atalk_iface **iface = &atalk_interfaces;
212 struct atalk_iface *tmp;
213
214 write_lock_bh(&atalk_interfaces_lock);
215 while ((tmp = *iface) != NULL) {
216 if (tmp->dev == dev) {
217 *iface = tmp->next;
218 dev_put(dev);
219 kfree(tmp);
220 dev->atalk_ptr = NULL;
221 } else
222 iface = &tmp->next;
223 }
224 write_unlock_bh(&atalk_interfaces_lock);
225 }
226
atif_add_device(struct net_device * dev,struct atalk_addr * sa)227 static struct atalk_iface *atif_add_device(struct net_device *dev,
228 struct atalk_addr *sa)
229 {
230 struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
231
232 if (!iface)
233 goto out;
234
235 dev_hold(dev);
236 iface->dev = dev;
237 dev->atalk_ptr = iface;
238 iface->address = *sa;
239 iface->status = 0;
240
241 write_lock_bh(&atalk_interfaces_lock);
242 iface->next = atalk_interfaces;
243 atalk_interfaces = iface;
244 write_unlock_bh(&atalk_interfaces_lock);
245 out:
246 return iface;
247 }
248
249 /* Perform phase 2 AARP probing on our tentative address */
atif_probe_device(struct atalk_iface * atif)250 static int atif_probe_device(struct atalk_iface *atif)
251 {
252 int netrange = ntohs(atif->nets.nr_lastnet) -
253 ntohs(atif->nets.nr_firstnet) + 1;
254 int probe_net = ntohs(atif->address.s_net);
255 int probe_node = atif->address.s_node;
256 int netct, nodect;
257
258 /* Offset the network we start probing with */
259 if (probe_net == ATADDR_ANYNET) {
260 probe_net = ntohs(atif->nets.nr_firstnet);
261 if (netrange)
262 probe_net += jiffies % netrange;
263 }
264 if (probe_node == ATADDR_ANYNODE)
265 probe_node = jiffies & 0xFF;
266
267 /* Scan the networks */
268 atif->status |= ATIF_PROBE;
269 for (netct = 0; netct <= netrange; netct++) {
270 /* Sweep the available nodes from a given start */
271 atif->address.s_net = htons(probe_net);
272 for (nodect = 0; nodect < 256; nodect++) {
273 atif->address.s_node = (nodect + probe_node) & 0xFF;
274 if (atif->address.s_node > 0 &&
275 atif->address.s_node < 254) {
276 /* Probe a proposed address */
277 aarp_probe_network(atif);
278
279 if (!(atif->status & ATIF_PROBE_FAIL)) {
280 atif->status &= ~ATIF_PROBE;
281 return 0;
282 }
283 }
284 atif->status &= ~ATIF_PROBE_FAIL;
285 }
286 probe_net++;
287 if (probe_net > ntohs(atif->nets.nr_lastnet))
288 probe_net = ntohs(atif->nets.nr_firstnet);
289 }
290 atif->status &= ~ATIF_PROBE;
291
292 return -EADDRINUSE; /* Network is full... */
293 }
294
295
296 /* Perform AARP probing for a proxy address */
atif_proxy_probe_device(struct atalk_iface * atif,struct atalk_addr * proxy_addr)297 static int atif_proxy_probe_device(struct atalk_iface *atif,
298 struct atalk_addr* proxy_addr)
299 {
300 int netrange = ntohs(atif->nets.nr_lastnet) -
301 ntohs(atif->nets.nr_firstnet) + 1;
302 /* we probe the interface's network */
303 int probe_net = ntohs(atif->address.s_net);
304 int probe_node = ATADDR_ANYNODE; /* we'll take anything */
305 int netct, nodect;
306
307 /* Offset the network we start probing with */
308 if (probe_net == ATADDR_ANYNET) {
309 probe_net = ntohs(atif->nets.nr_firstnet);
310 if (netrange)
311 probe_net += jiffies % netrange;
312 }
313
314 if (probe_node == ATADDR_ANYNODE)
315 probe_node = jiffies & 0xFF;
316
317 /* Scan the networks */
318 for (netct = 0; netct <= netrange; netct++) {
319 /* Sweep the available nodes from a given start */
320 proxy_addr->s_net = htons(probe_net);
321 for (nodect = 0; nodect < 256; nodect++) {
322 proxy_addr->s_node = (nodect + probe_node) & 0xFF;
323 if (proxy_addr->s_node > 0 &&
324 proxy_addr->s_node < 254) {
325 /* Tell AARP to probe a proposed address */
326 int ret = aarp_proxy_probe_network(atif,
327 proxy_addr);
328
329 if (ret != -EADDRINUSE)
330 return ret;
331 }
332 }
333 probe_net++;
334 if (probe_net > ntohs(atif->nets.nr_lastnet))
335 probe_net = ntohs(atif->nets.nr_firstnet);
336 }
337
338 return -EADDRINUSE; /* Network is full... */
339 }
340
341
atalk_find_dev_addr(struct net_device * dev)342 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
343 {
344 struct atalk_iface *iface = dev->atalk_ptr;
345 return iface ? &iface->address : NULL;
346 }
347
atalk_find_primary(void)348 static struct atalk_addr *atalk_find_primary(void)
349 {
350 struct atalk_iface *fiface = NULL;
351 struct atalk_addr *retval;
352 struct atalk_iface *iface;
353
354 /*
355 * Return a point-to-point interface only if
356 * there is no non-ptp interface available.
357 */
358 read_lock_bh(&atalk_interfaces_lock);
359 for (iface = atalk_interfaces; iface; iface = iface->next) {
360 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
361 fiface = iface;
362 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
363 retval = &iface->address;
364 goto out;
365 }
366 }
367
368 if (fiface)
369 retval = &fiface->address;
370 else if (atalk_interfaces)
371 retval = &atalk_interfaces->address;
372 else
373 retval = NULL;
374 out:
375 read_unlock_bh(&atalk_interfaces_lock);
376 return retval;
377 }
378
379 /*
380 * Find a match for 'any network' - ie any of our interfaces with that
381 * node number will do just nicely.
382 */
atalk_find_anynet(int node,struct net_device * dev)383 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
384 {
385 struct atalk_iface *iface = dev->atalk_ptr;
386
387 if (!iface || iface->status & ATIF_PROBE)
388 goto out_err;
389
390 if (node != ATADDR_BCAST &&
391 iface->address.s_node != node &&
392 node != ATADDR_ANYNODE)
393 goto out_err;
394 out:
395 return iface;
396 out_err:
397 iface = NULL;
398 goto out;
399 }
400
401 /* Find a match for a specific network:node pair */
atalk_find_interface(__be16 net,int node)402 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
403 {
404 struct atalk_iface *iface;
405
406 read_lock_bh(&atalk_interfaces_lock);
407 for (iface = atalk_interfaces; iface; iface = iface->next) {
408 if ((node == ATADDR_BCAST ||
409 node == ATADDR_ANYNODE ||
410 iface->address.s_node == node) &&
411 iface->address.s_net == net &&
412 !(iface->status & ATIF_PROBE))
413 break;
414
415 /* XXXX.0 -- net.0 returns the iface associated with net */
416 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
417 ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
418 ntohs(net) <= ntohs(iface->nets.nr_lastnet))
419 break;
420 }
421 read_unlock_bh(&atalk_interfaces_lock);
422 return iface;
423 }
424
425
426 /*
427 * Find a route for an AppleTalk packet. This ought to get cached in
428 * the socket (later on...). We know about host routes and the fact
429 * that a route must be direct to broadcast.
430 */
atrtr_find(struct atalk_addr * target)431 static struct atalk_route *atrtr_find(struct atalk_addr *target)
432 {
433 /*
434 * we must search through all routes unless we find a
435 * host route, because some host routes might overlap
436 * network routes
437 */
438 struct atalk_route *net_route = NULL;
439 struct atalk_route *r;
440
441 read_lock_bh(&atalk_routes_lock);
442 for (r = atalk_routes; r; r = r->next) {
443 if (!(r->flags & RTF_UP))
444 continue;
445
446 if (r->target.s_net == target->s_net) {
447 if (r->flags & RTF_HOST) {
448 /*
449 * if this host route is for the target,
450 * the we're done
451 */
452 if (r->target.s_node == target->s_node)
453 goto out;
454 } else
455 /*
456 * this route will work if there isn't a
457 * direct host route, so cache it
458 */
459 net_route = r;
460 }
461 }
462
463 /*
464 * if we found a network route but not a direct host
465 * route, then return it
466 */
467 if (net_route)
468 r = net_route;
469 else if (atrtr_default.dev)
470 r = &atrtr_default;
471 else /* No route can be found */
472 r = NULL;
473 out:
474 read_unlock_bh(&atalk_routes_lock);
475 return r;
476 }
477
478
479 /*
480 * Given an AppleTalk network, find the device to use. This can be
481 * a simple lookup.
482 */
atrtr_get_dev(struct atalk_addr * sa)483 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
484 {
485 struct atalk_route *atr = atrtr_find(sa);
486 return atr ? atr->dev : NULL;
487 }
488
489 /* Set up a default router */
atrtr_set_default(struct net_device * dev)490 static void atrtr_set_default(struct net_device *dev)
491 {
492 atrtr_default.dev = dev;
493 atrtr_default.flags = RTF_UP;
494 atrtr_default.gateway.s_net = htons(0);
495 atrtr_default.gateway.s_node = 0;
496 }
497
498 /*
499 * Add a router. Basically make sure it looks valid and stuff the
500 * entry in the list. While it uses netranges we always set them to one
501 * entry to work like netatalk.
502 */
atrtr_create(struct rtentry * r,struct net_device * devhint)503 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
504 {
505 struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
506 struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
507 struct atalk_route *rt;
508 struct atalk_iface *iface, *riface;
509 int retval = -EINVAL;
510
511 /*
512 * Fixme: Raise/Lower a routing change semaphore for these
513 * operations.
514 */
515
516 /* Validate the request */
517 if (ta->sat_family != AF_APPLETALK ||
518 (!devhint && ga->sat_family != AF_APPLETALK))
519 goto out;
520
521 /* Now walk the routing table and make our decisions */
522 write_lock_bh(&atalk_routes_lock);
523 for (rt = atalk_routes; rt; rt = rt->next) {
524 if (r->rt_flags != rt->flags)
525 continue;
526
527 if (ta->sat_addr.s_net == rt->target.s_net) {
528 if (!(rt->flags & RTF_HOST))
529 break;
530 if (ta->sat_addr.s_node == rt->target.s_node)
531 break;
532 }
533 }
534
535 if (!devhint) {
536 riface = NULL;
537
538 read_lock_bh(&atalk_interfaces_lock);
539 for (iface = atalk_interfaces; iface; iface = iface->next) {
540 if (!riface &&
541 ntohs(ga->sat_addr.s_net) >=
542 ntohs(iface->nets.nr_firstnet) &&
543 ntohs(ga->sat_addr.s_net) <=
544 ntohs(iface->nets.nr_lastnet))
545 riface = iface;
546
547 if (ga->sat_addr.s_net == iface->address.s_net &&
548 ga->sat_addr.s_node == iface->address.s_node)
549 riface = iface;
550 }
551 read_unlock_bh(&atalk_interfaces_lock);
552
553 retval = -ENETUNREACH;
554 if (!riface)
555 goto out_unlock;
556
557 devhint = riface->dev;
558 }
559
560 if (!rt) {
561 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
562
563 retval = -ENOBUFS;
564 if (!rt)
565 goto out_unlock;
566
567 rt->next = atalk_routes;
568 atalk_routes = rt;
569 }
570
571 /* Fill in the routing entry */
572 rt->target = ta->sat_addr;
573 dev_hold(devhint);
574 rt->dev = devhint;
575 rt->flags = r->rt_flags;
576 rt->gateway = ga->sat_addr;
577
578 retval = 0;
579 out_unlock:
580 write_unlock_bh(&atalk_routes_lock);
581 out:
582 return retval;
583 }
584
585 /* Delete a route. Find it and discard it */
atrtr_delete(struct atalk_addr * addr)586 static int atrtr_delete(struct atalk_addr * addr)
587 {
588 struct atalk_route **r = &atalk_routes;
589 int retval = 0;
590 struct atalk_route *tmp;
591
592 write_lock_bh(&atalk_routes_lock);
593 while ((tmp = *r) != NULL) {
594 if (tmp->target.s_net == addr->s_net &&
595 (!(tmp->flags&RTF_GATEWAY) ||
596 tmp->target.s_node == addr->s_node)) {
597 *r = tmp->next;
598 dev_put(tmp->dev);
599 kfree(tmp);
600 goto out;
601 }
602 r = &tmp->next;
603 }
604 retval = -ENOENT;
605 out:
606 write_unlock_bh(&atalk_routes_lock);
607 return retval;
608 }
609
610 /*
611 * Called when a device is downed. Just throw away any routes
612 * via it.
613 */
atrtr_device_down(struct net_device * dev)614 static void atrtr_device_down(struct net_device *dev)
615 {
616 struct atalk_route **r = &atalk_routes;
617 struct atalk_route *tmp;
618
619 write_lock_bh(&atalk_routes_lock);
620 while ((tmp = *r) != NULL) {
621 if (tmp->dev == dev) {
622 *r = tmp->next;
623 dev_put(dev);
624 kfree(tmp);
625 } else
626 r = &tmp->next;
627 }
628 write_unlock_bh(&atalk_routes_lock);
629
630 if (atrtr_default.dev == dev)
631 atrtr_set_default(NULL);
632 }
633
634 /* Actually down the interface */
atalk_dev_down(struct net_device * dev)635 static inline void atalk_dev_down(struct net_device *dev)
636 {
637 atrtr_device_down(dev); /* Remove all routes for the device */
638 aarp_device_down(dev); /* Remove AARP entries for the device */
639 atif_drop_device(dev); /* Remove the device */
640 }
641
642 /*
643 * A device event has occurred. Watch for devices going down and
644 * delete our use of them (iface and route).
645 */
ddp_device_event(struct notifier_block * this,unsigned long event,void * ptr)646 static int ddp_device_event(struct notifier_block *this, unsigned long event,
647 void *ptr)
648 {
649 struct net_device *dev = ptr;
650
651 if (!net_eq(dev_net(dev), &init_net))
652 return NOTIFY_DONE;
653
654 if (event == NETDEV_DOWN)
655 /* Discard any use of this */
656 atalk_dev_down(dev);
657
658 return NOTIFY_DONE;
659 }
660
661 /* ioctl calls. Shouldn't even need touching */
662 /* Device configuration ioctl calls */
atif_ioctl(int cmd,void __user * arg)663 static int atif_ioctl(int cmd, void __user *arg)
664 {
665 static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
666 struct ifreq atreq;
667 struct atalk_netrange *nr;
668 struct sockaddr_at *sa;
669 struct net_device *dev;
670 struct atalk_iface *atif;
671 int ct;
672 int limit;
673 struct rtentry rtdef;
674 int add_route;
675
676 if (copy_from_user(&atreq, arg, sizeof(atreq)))
677 return -EFAULT;
678
679 dev = __dev_get_by_name(&init_net, atreq.ifr_name);
680 if (!dev)
681 return -ENODEV;
682
683 sa = (struct sockaddr_at *)&atreq.ifr_addr;
684 atif = atalk_find_dev(dev);
685
686 switch (cmd) {
687 case SIOCSIFADDR:
688 if (!capable(CAP_NET_ADMIN))
689 return -EPERM;
690 if (sa->sat_family != AF_APPLETALK)
691 return -EINVAL;
692 if (dev->type != ARPHRD_ETHER &&
693 dev->type != ARPHRD_LOOPBACK &&
694 dev->type != ARPHRD_LOCALTLK &&
695 dev->type != ARPHRD_PPP)
696 return -EPROTONOSUPPORT;
697
698 nr = (struct atalk_netrange *)&sa->sat_zero[0];
699 add_route = 1;
700
701 /*
702 * if this is a point-to-point iface, and we already
703 * have an iface for this AppleTalk address, then we
704 * should not add a route
705 */
706 if ((dev->flags & IFF_POINTOPOINT) &&
707 atalk_find_interface(sa->sat_addr.s_net,
708 sa->sat_addr.s_node)) {
709 printk(KERN_DEBUG "AppleTalk: point-to-point "
710 "interface added with "
711 "existing address\n");
712 add_route = 0;
713 }
714
715 /*
716 * Phase 1 is fine on LocalTalk but we don't do
717 * EtherTalk phase 1. Anyone wanting to add it go ahead.
718 */
719 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
720 return -EPROTONOSUPPORT;
721 if (sa->sat_addr.s_node == ATADDR_BCAST ||
722 sa->sat_addr.s_node == 254)
723 return -EINVAL;
724 if (atif) {
725 /* Already setting address */
726 if (atif->status & ATIF_PROBE)
727 return -EBUSY;
728
729 atif->address.s_net = sa->sat_addr.s_net;
730 atif->address.s_node = sa->sat_addr.s_node;
731 atrtr_device_down(dev); /* Flush old routes */
732 } else {
733 atif = atif_add_device(dev, &sa->sat_addr);
734 if (!atif)
735 return -ENOMEM;
736 }
737 atif->nets = *nr;
738
739 /*
740 * Check if the chosen address is used. If so we
741 * error and atalkd will try another.
742 */
743
744 if (!(dev->flags & IFF_LOOPBACK) &&
745 !(dev->flags & IFF_POINTOPOINT) &&
746 atif_probe_device(atif) < 0) {
747 atif_drop_device(dev);
748 return -EADDRINUSE;
749 }
750
751 /* Hey it worked - add the direct routes */
752 sa = (struct sockaddr_at *)&rtdef.rt_gateway;
753 sa->sat_family = AF_APPLETALK;
754 sa->sat_addr.s_net = atif->address.s_net;
755 sa->sat_addr.s_node = atif->address.s_node;
756 sa = (struct sockaddr_at *)&rtdef.rt_dst;
757 rtdef.rt_flags = RTF_UP;
758 sa->sat_family = AF_APPLETALK;
759 sa->sat_addr.s_node = ATADDR_ANYNODE;
760 if (dev->flags & IFF_LOOPBACK ||
761 dev->flags & IFF_POINTOPOINT)
762 rtdef.rt_flags |= RTF_HOST;
763
764 /* Routerless initial state */
765 if (nr->nr_firstnet == htons(0) &&
766 nr->nr_lastnet == htons(0xFFFE)) {
767 sa->sat_addr.s_net = atif->address.s_net;
768 atrtr_create(&rtdef, dev);
769 atrtr_set_default(dev);
770 } else {
771 limit = ntohs(nr->nr_lastnet);
772 if (limit - ntohs(nr->nr_firstnet) > 4096) {
773 printk(KERN_WARNING "Too many routes/"
774 "iface.\n");
775 return -EINVAL;
776 }
777 if (add_route)
778 for (ct = ntohs(nr->nr_firstnet);
779 ct <= limit; ct++) {
780 sa->sat_addr.s_net = htons(ct);
781 atrtr_create(&rtdef, dev);
782 }
783 }
784 dev_mc_add_global(dev, aarp_mcast);
785 return 0;
786
787 case SIOCGIFADDR:
788 if (!atif)
789 return -EADDRNOTAVAIL;
790
791 sa->sat_family = AF_APPLETALK;
792 sa->sat_addr = atif->address;
793 break;
794
795 case SIOCGIFBRDADDR:
796 if (!atif)
797 return -EADDRNOTAVAIL;
798
799 sa->sat_family = AF_APPLETALK;
800 sa->sat_addr.s_net = atif->address.s_net;
801 sa->sat_addr.s_node = ATADDR_BCAST;
802 break;
803
804 case SIOCATALKDIFADDR:
805 case SIOCDIFADDR:
806 if (!capable(CAP_NET_ADMIN))
807 return -EPERM;
808 if (sa->sat_family != AF_APPLETALK)
809 return -EINVAL;
810 atalk_dev_down(dev);
811 break;
812
813 case SIOCSARP:
814 if (!capable(CAP_NET_ADMIN))
815 return -EPERM;
816 if (sa->sat_family != AF_APPLETALK)
817 return -EINVAL;
818 /*
819 * for now, we only support proxy AARP on ELAP;
820 * we should be able to do it for LocalTalk, too.
821 */
822 if (dev->type != ARPHRD_ETHER)
823 return -EPROTONOSUPPORT;
824
825 /*
826 * atif points to the current interface on this network;
827 * we aren't concerned about its current status (at
828 * least for now), but it has all the settings about
829 * the network we're going to probe. Consequently, it
830 * must exist.
831 */
832 if (!atif)
833 return -EADDRNOTAVAIL;
834
835 nr = (struct atalk_netrange *)&(atif->nets);
836 /*
837 * Phase 1 is fine on Localtalk but we don't do
838 * Ethertalk phase 1. Anyone wanting to add it go ahead.
839 */
840 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
841 return -EPROTONOSUPPORT;
842
843 if (sa->sat_addr.s_node == ATADDR_BCAST ||
844 sa->sat_addr.s_node == 254)
845 return -EINVAL;
846
847 /*
848 * Check if the chosen address is used. If so we
849 * error and ATCP will try another.
850 */
851 if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
852 return -EADDRINUSE;
853
854 /*
855 * We now have an address on the local network, and
856 * the AARP code will defend it for us until we take it
857 * down. We don't set up any routes right now, because
858 * ATCP will install them manually via SIOCADDRT.
859 */
860 break;
861
862 case SIOCDARP:
863 if (!capable(CAP_NET_ADMIN))
864 return -EPERM;
865 if (sa->sat_family != AF_APPLETALK)
866 return -EINVAL;
867 if (!atif)
868 return -EADDRNOTAVAIL;
869
870 /* give to aarp module to remove proxy entry */
871 aarp_proxy_remove(atif->dev, &(sa->sat_addr));
872 return 0;
873 }
874
875 return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
876 }
877
878 /* Routing ioctl() calls */
atrtr_ioctl(unsigned int cmd,void __user * arg)879 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
880 {
881 struct rtentry rt;
882
883 if (copy_from_user(&rt, arg, sizeof(rt)))
884 return -EFAULT;
885
886 switch (cmd) {
887 case SIOCDELRT:
888 if (rt.rt_dst.sa_family != AF_APPLETALK)
889 return -EINVAL;
890 return atrtr_delete(&((struct sockaddr_at *)
891 &rt.rt_dst)->sat_addr);
892
893 case SIOCADDRT: {
894 struct net_device *dev = NULL;
895 if (rt.rt_dev) {
896 char name[IFNAMSIZ];
897 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
898 return -EFAULT;
899 name[IFNAMSIZ-1] = '\0';
900 dev = __dev_get_by_name(&init_net, name);
901 if (!dev)
902 return -ENODEV;
903 }
904 return atrtr_create(&rt, dev);
905 }
906 }
907 return -EINVAL;
908 }
909
910 /**************************************************************************\
911 * *
912 * Handling for system calls applied via the various interfaces to an *
913 * AppleTalk socket object. *
914 * *
915 \**************************************************************************/
916
917 /*
918 * Checksum: This is 'optional'. It's quite likely also a good
919 * candidate for assembler hackery 8)
920 */
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
955 WARN_ON(start > offset + len);
956
957 end = start + skb_shinfo(skb)->frags[i].size;
958 if ((copy = end - offset) > 0) {
959 u8 *vaddr;
960 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
961
962 if (copy > len)
963 copy = len;
964 vaddr = kmap_skb_frag(frag);
965 sum = atalk_sum_partial(vaddr + frag->page_offset +
966 offset - start, copy, sum);
967 kunmap_skb_frag(vaddr);
968
969 if (!(len -= copy))
970 return sum;
971 offset += copy;
972 }
973 start = end;
974 }
975
976 skb_walk_frags(skb, frag_iter) {
977 int end;
978
979 WARN_ON(start > offset + len);
980
981 end = start + frag_iter->len;
982 if ((copy = end - offset) > 0) {
983 if (copy > len)
984 copy = len;
985 sum = atalk_sum_skb(frag_iter, offset - start,
986 copy, sum);
987 if ((len -= copy) == 0)
988 return sum;
989 offset += copy;
990 }
991 start = end;
992 }
993
994 BUG_ON(len > 0);
995
996 return sum;
997 }
998
atalk_checksum(const struct sk_buff * skb,int len)999 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1000 {
1001 unsigned long sum;
1002
1003 /* skip header 4 bytes */
1004 sum = atalk_sum_skb(skb, 4, len-4, 0);
1005
1006 /* Use 0xFFFF for 0. 0 itself means none */
1007 return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1008 }
1009
1010 static struct proto ddp_proto = {
1011 .name = "DDP",
1012 .owner = THIS_MODULE,
1013 .obj_size = sizeof(struct atalk_sock),
1014 };
1015
1016 /*
1017 * Create a socket. Initialise the socket, blank the addresses
1018 * set the state.
1019 */
atalk_create(struct net * net,struct socket * sock,int protocol,int kern)1020 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1021 int kern)
1022 {
1023 struct sock *sk;
1024 int rc = -ESOCKTNOSUPPORT;
1025
1026 if (!net_eq(net, &init_net))
1027 return -EAFNOSUPPORT;
1028
1029 /*
1030 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1031 * and gives you the full ELAP frame. Should be handy for CAP 8)
1032 */
1033 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1034 goto out;
1035 rc = -ENOMEM;
1036 sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1037 if (!sk)
1038 goto out;
1039 rc = 0;
1040 sock->ops = &atalk_dgram_ops;
1041 sock_init_data(sock, sk);
1042
1043 /* Checksums on by default */
1044 sock_set_flag(sk, SOCK_ZAPPED);
1045 out:
1046 return rc;
1047 }
1048
1049 /* Free a socket. No work needed */
atalk_release(struct socket * sock)1050 static int atalk_release(struct socket *sock)
1051 {
1052 struct sock *sk = sock->sk;
1053
1054 if (sk) {
1055 sock_hold(sk);
1056 lock_sock(sk);
1057
1058 sock_orphan(sk);
1059 sock->sk = NULL;
1060 atalk_destroy_socket(sk);
1061
1062 release_sock(sk);
1063 sock_put(sk);
1064 }
1065 return 0;
1066 }
1067
1068 /**
1069 * atalk_pick_and_bind_port - Pick a source port when one is not given
1070 * @sk - socket to insert into the tables
1071 * @sat - address to search for
1072 *
1073 * Pick a source port when one is not given. If we can find a suitable free
1074 * one, we insert the socket into the tables using it.
1075 *
1076 * This whole operation must be atomic.
1077 */
atalk_pick_and_bind_port(struct sock * sk,struct sockaddr_at * sat)1078 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1079 {
1080 int retval;
1081
1082 write_lock_bh(&atalk_sockets_lock);
1083
1084 for (sat->sat_port = ATPORT_RESERVED;
1085 sat->sat_port < ATPORT_LAST;
1086 sat->sat_port++) {
1087 struct sock *s;
1088 struct hlist_node *node;
1089
1090 sk_for_each(s, node, &atalk_sockets) {
1091 struct atalk_sock *at = at_sk(s);
1092
1093 if (at->src_net == sat->sat_addr.s_net &&
1094 at->src_node == sat->sat_addr.s_node &&
1095 at->src_port == sat->sat_port)
1096 goto try_next_port;
1097 }
1098
1099 /* Wheee, it's free, assign and insert. */
1100 __atalk_insert_socket(sk);
1101 at_sk(sk)->src_port = sat->sat_port;
1102 retval = 0;
1103 goto out;
1104
1105 try_next_port:;
1106 }
1107
1108 retval = -EBUSY;
1109 out:
1110 write_unlock_bh(&atalk_sockets_lock);
1111 return retval;
1112 }
1113
atalk_autobind(struct sock * sk)1114 static int atalk_autobind(struct sock *sk)
1115 {
1116 struct atalk_sock *at = at_sk(sk);
1117 struct sockaddr_at sat;
1118 struct atalk_addr *ap = atalk_find_primary();
1119 int n = -EADDRNOTAVAIL;
1120
1121 if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1122 goto out;
1123
1124 at->src_net = sat.sat_addr.s_net = ap->s_net;
1125 at->src_node = sat.sat_addr.s_node = ap->s_node;
1126
1127 n = atalk_pick_and_bind_port(sk, &sat);
1128 if (!n)
1129 sock_reset_flag(sk, SOCK_ZAPPED);
1130 out:
1131 return n;
1132 }
1133
1134 /* Set the address 'our end' of the connection */
atalk_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)1135 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1136 {
1137 struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1138 struct sock *sk = sock->sk;
1139 struct atalk_sock *at = at_sk(sk);
1140 int err;
1141
1142 if (!sock_flag(sk, SOCK_ZAPPED) ||
1143 addr_len != sizeof(struct sockaddr_at))
1144 return -EINVAL;
1145
1146 if (addr->sat_family != AF_APPLETALK)
1147 return -EAFNOSUPPORT;
1148
1149 lock_sock(sk);
1150 if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1151 struct atalk_addr *ap = atalk_find_primary();
1152
1153 err = -EADDRNOTAVAIL;
1154 if (!ap)
1155 goto out;
1156
1157 at->src_net = addr->sat_addr.s_net = ap->s_net;
1158 at->src_node = addr->sat_addr.s_node= ap->s_node;
1159 } else {
1160 err = -EADDRNOTAVAIL;
1161 if (!atalk_find_interface(addr->sat_addr.s_net,
1162 addr->sat_addr.s_node))
1163 goto out;
1164
1165 at->src_net = addr->sat_addr.s_net;
1166 at->src_node = addr->sat_addr.s_node;
1167 }
1168
1169 if (addr->sat_port == ATADDR_ANYPORT) {
1170 err = atalk_pick_and_bind_port(sk, addr);
1171
1172 if (err < 0)
1173 goto out;
1174 } else {
1175 at->src_port = addr->sat_port;
1176
1177 err = -EADDRINUSE;
1178 if (atalk_find_or_insert_socket(sk, addr))
1179 goto out;
1180 }
1181
1182 sock_reset_flag(sk, SOCK_ZAPPED);
1183 err = 0;
1184 out:
1185 release_sock(sk);
1186 return err;
1187 }
1188
1189 /* Set the address we talk to */
atalk_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)1190 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1191 int addr_len, int flags)
1192 {
1193 struct sock *sk = sock->sk;
1194 struct atalk_sock *at = at_sk(sk);
1195 struct sockaddr_at *addr;
1196 int err;
1197
1198 sk->sk_state = TCP_CLOSE;
1199 sock->state = SS_UNCONNECTED;
1200
1201 if (addr_len != sizeof(*addr))
1202 return -EINVAL;
1203
1204 addr = (struct sockaddr_at *)uaddr;
1205
1206 if (addr->sat_family != AF_APPLETALK)
1207 return -EAFNOSUPPORT;
1208
1209 if (addr->sat_addr.s_node == ATADDR_BCAST &&
1210 !sock_flag(sk, SOCK_BROADCAST)) {
1211 #if 1
1212 printk(KERN_WARNING "%s is broken and did not set "
1213 "SO_BROADCAST. It will break when 2.2 is "
1214 "released.\n",
1215 current->comm);
1216 #else
1217 return -EACCES;
1218 #endif
1219 }
1220
1221 lock_sock(sk);
1222 err = -EBUSY;
1223 if (sock_flag(sk, SOCK_ZAPPED))
1224 if (atalk_autobind(sk) < 0)
1225 goto out;
1226
1227 err = -ENETUNREACH;
1228 if (!atrtr_get_dev(&addr->sat_addr))
1229 goto out;
1230
1231 at->dest_port = addr->sat_port;
1232 at->dest_net = addr->sat_addr.s_net;
1233 at->dest_node = addr->sat_addr.s_node;
1234
1235 sock->state = SS_CONNECTED;
1236 sk->sk_state = TCP_ESTABLISHED;
1237 err = 0;
1238 out:
1239 release_sock(sk);
1240 return err;
1241 }
1242
1243 /*
1244 * Find the name of an AppleTalk socket. Just copy the right
1245 * fields into the sockaddr.
1246 */
atalk_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)1247 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1248 int *uaddr_len, int peer)
1249 {
1250 struct sockaddr_at sat;
1251 struct sock *sk = sock->sk;
1252 struct atalk_sock *at = at_sk(sk);
1253 int err;
1254
1255 lock_sock(sk);
1256 err = -ENOBUFS;
1257 if (sock_flag(sk, SOCK_ZAPPED))
1258 if (atalk_autobind(sk) < 0)
1259 goto out;
1260
1261 *uaddr_len = sizeof(struct sockaddr_at);
1262 memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
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 err = 0;
1279 sat.sat_family = AF_APPLETALK;
1280 memcpy(uaddr, &sat, sizeof(sat));
1281
1282 out:
1283 release_sock(sk);
1284 return err;
1285 }
1286
1287 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
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 *
1414 * Receive a packet (in skb) from device dev. This has come from the SNAP
1415 * decoder, and on entry skb->transport_header is the DDP header, skb->len
1416 * is the DDP header, skb->len is the DDP length. The physical headers
1417 * have been extracted. PPP should probably pass frames marked as for this
1418 * layer. [ie ARPHRD_ETHERTALK]
1419 */
atalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1420 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1421 struct packet_type *pt, struct net_device *orig_dev)
1422 {
1423 struct ddpehdr *ddp;
1424 struct sock *sock;
1425 struct atalk_iface *atif;
1426 struct sockaddr_at tosat;
1427 int origlen;
1428 __u16 len_hops;
1429
1430 if (!net_eq(dev_net(dev), &init_net))
1431 goto drop;
1432
1433 /* Don't mangle buffer if shared */
1434 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1435 goto out;
1436
1437 /* Size check and make sure header is contiguous */
1438 if (!pskb_may_pull(skb, sizeof(*ddp)))
1439 goto drop;
1440
1441 ddp = ddp_hdr(skb);
1442
1443 len_hops = ntohs(ddp->deh_len_hops);
1444
1445 /* Trim buffer in case of stray trailing data */
1446 origlen = skb->len;
1447 skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1448
1449 /*
1450 * Size check to see if ddp->deh_len was crap
1451 * (Otherwise we'll detonate most spectacularly
1452 * in the middle of atalk_checksum() or recvmsg()).
1453 */
1454 if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1455 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1456 "skb->len=%u)\n", len_hops & 1023, skb->len);
1457 goto drop;
1458 }
1459
1460 /*
1461 * Any checksums. Note we don't do htons() on this == is assumed to be
1462 * valid for net byte orders all over the networking code...
1463 */
1464 if (ddp->deh_sum &&
1465 atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1466 /* Not a valid AppleTalk frame - dustbin time */
1467 goto drop;
1468
1469 /* Check the packet is aimed at us */
1470 if (!ddp->deh_dnet) /* Net 0 is 'this network' */
1471 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1472 else
1473 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1474
1475 if (!atif) {
1476 /* Not ours, so we route the packet via the correct
1477 * AppleTalk iface
1478 */
1479 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1480 }
1481
1482 /* if IP over DDP is not selected this code will be optimized out */
1483 if (is_ip_over_ddp(skb))
1484 return handle_ip_over_ddp(skb);
1485 /*
1486 * Which socket - atalk_search_socket() looks for a *full match*
1487 * of the <net, node, port> tuple.
1488 */
1489 tosat.sat_addr.s_net = ddp->deh_dnet;
1490 tosat.sat_addr.s_node = ddp->deh_dnode;
1491 tosat.sat_port = ddp->deh_dport;
1492
1493 sock = atalk_search_socket(&tosat, atif);
1494 if (!sock) /* But not one of our sockets */
1495 goto drop;
1496
1497 /* Queue packet (standard) */
1498 skb->sk = sock;
1499
1500 if (sock_queue_rcv_skb(sock, skb) < 0)
1501 goto drop;
1502
1503 return NET_RX_SUCCESS;
1504
1505 drop:
1506 kfree_skb(skb);
1507 out:
1508 return NET_RX_DROP;
1509
1510 }
1511
1512 /*
1513 * Receive a LocalTalk frame. We make some demands on the caller here.
1514 * Caller must provide enough headroom on the packet to pull the short
1515 * header and append a long one.
1516 */
ltalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1517 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1518 struct packet_type *pt, struct net_device *orig_dev)
1519 {
1520 if (!net_eq(dev_net(dev), &init_net))
1521 goto freeit;
1522
1523 /* Expand any short form frames */
1524 if (skb_mac_header(skb)[2] == 1) {
1525 struct ddpehdr *ddp;
1526 /* Find our address */
1527 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1528
1529 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1530 goto freeit;
1531
1532 /* Don't mangle buffer if shared */
1533 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1534 return 0;
1535
1536 /*
1537 * The push leaves us with a ddephdr not an shdr, and
1538 * handily the port bytes in the right place preset.
1539 */
1540 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1541
1542 /* Now fill in the long header */
1543
1544 /*
1545 * These two first. The mac overlays the new source/dest
1546 * network information so we MUST copy these before
1547 * we write the network numbers !
1548 */
1549
1550 ddp->deh_dnode = skb_mac_header(skb)[0]; /* From physical header */
1551 ddp->deh_snode = skb_mac_header(skb)[1]; /* From physical header */
1552
1553 ddp->deh_dnet = ap->s_net; /* Network number */
1554 ddp->deh_snet = ap->s_net;
1555 ddp->deh_sum = 0; /* No checksum */
1556 /*
1557 * Not sure about this bit...
1558 */
1559 /* Non routable, so force a drop if we slip up later */
1560 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1561 }
1562 skb_reset_transport_header(skb);
1563
1564 return atalk_rcv(skb, dev, pt, orig_dev);
1565 freeit:
1566 kfree_skb(skb);
1567 return 0;
1568 }
1569
atalk_sendmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t len)1570 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1571 size_t len)
1572 {
1573 struct sock *sk = sock->sk;
1574 struct atalk_sock *at = at_sk(sk);
1575 struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1576 int flags = msg->msg_flags;
1577 int loopback = 0;
1578 struct sockaddr_at local_satalk, gsat;
1579 struct sk_buff *skb;
1580 struct net_device *dev;
1581 struct ddpehdr *ddp;
1582 int size;
1583 struct atalk_route *rt;
1584 int err;
1585
1586 if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1587 return -EINVAL;
1588
1589 if (len > DDP_MAXSZ)
1590 return -EMSGSIZE;
1591
1592 lock_sock(sk);
1593 if (usat) {
1594 err = -EBUSY;
1595 if (sock_flag(sk, SOCK_ZAPPED))
1596 if (atalk_autobind(sk) < 0)
1597 goto out;
1598
1599 err = -EINVAL;
1600 if (msg->msg_namelen < sizeof(*usat) ||
1601 usat->sat_family != AF_APPLETALK)
1602 goto out;
1603
1604 err = -EPERM;
1605 /* netatalk didn't implement this check */
1606 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1607 !sock_flag(sk, SOCK_BROADCAST)) {
1608 goto out;
1609 }
1610 } else {
1611 err = -ENOTCONN;
1612 if (sk->sk_state != TCP_ESTABLISHED)
1613 goto out;
1614 usat = &local_satalk;
1615 usat->sat_family = AF_APPLETALK;
1616 usat->sat_port = at->dest_port;
1617 usat->sat_addr.s_node = at->dest_node;
1618 usat->sat_addr.s_net = at->dest_net;
1619 }
1620
1621 /* Build a packet */
1622 SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1623
1624 /* For headers */
1625 size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1626
1627 if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1628 rt = atrtr_find(&usat->sat_addr);
1629 } else {
1630 struct atalk_addr at_hint;
1631
1632 at_hint.s_node = 0;
1633 at_hint.s_net = at->src_net;
1634
1635 rt = atrtr_find(&at_hint);
1636 }
1637 err = ENETUNREACH;
1638 if (!rt)
1639 goto out;
1640
1641 dev = rt->dev;
1642
1643 SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1644 sk, size, dev->name);
1645
1646 size += dev->hard_header_len;
1647 release_sock(sk);
1648 skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1649 lock_sock(sk);
1650 if (!skb)
1651 goto out;
1652
1653 skb->sk = sk;
1654 skb_reserve(skb, ddp_dl->header_length);
1655 skb_reserve(skb, dev->hard_header_len);
1656 skb->dev = dev;
1657
1658 SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1659
1660 ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1661 ddp->deh_len_hops = htons(len + sizeof(*ddp));
1662 ddp->deh_dnet = usat->sat_addr.s_net;
1663 ddp->deh_snet = at->src_net;
1664 ddp->deh_dnode = usat->sat_addr.s_node;
1665 ddp->deh_snode = at->src_node;
1666 ddp->deh_dport = usat->sat_port;
1667 ddp->deh_sport = at->src_port;
1668
1669 SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1670
1671 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1672 if (err) {
1673 kfree_skb(skb);
1674 err = -EFAULT;
1675 goto out;
1676 }
1677
1678 if (sk->sk_no_check == 1)
1679 ddp->deh_sum = 0;
1680 else
1681 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1682
1683 /*
1684 * Loopback broadcast packets to non gateway targets (ie routes
1685 * to group we are in)
1686 */
1687 if (ddp->deh_dnode == ATADDR_BCAST &&
1688 !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1689 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1690
1691 if (skb2) {
1692 loopback = 1;
1693 SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1694 /*
1695 * If it fails it is queued/sent above in the aarp queue
1696 */
1697 aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1698 }
1699 }
1700
1701 if (dev->flags & IFF_LOOPBACK || loopback) {
1702 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1703 /* loop back */
1704 skb_orphan(skb);
1705 if (ddp->deh_dnode == ATADDR_BCAST) {
1706 struct atalk_addr at_lo;
1707
1708 at_lo.s_node = 0;
1709 at_lo.s_net = 0;
1710
1711 rt = atrtr_find(&at_lo);
1712 if (!rt) {
1713 kfree_skb(skb);
1714 err = -ENETUNREACH;
1715 goto out;
1716 }
1717 dev = rt->dev;
1718 skb->dev = dev;
1719 }
1720 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1721 } else {
1722 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1723 if (rt->flags & RTF_GATEWAY) {
1724 gsat.sat_addr = rt->gateway;
1725 usat = &gsat;
1726 }
1727
1728 /*
1729 * If it fails it is queued/sent above in the aarp queue
1730 */
1731 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1732 }
1733 SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1734
1735 out:
1736 release_sock(sk);
1737 return err ? : len;
1738 }
1739
atalk_recvmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size,int flags)1740 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1741 size_t size, int flags)
1742 {
1743 struct sock *sk = sock->sk;
1744 struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1745 struct ddpehdr *ddp;
1746 int copied = 0;
1747 int offset = 0;
1748 int err = 0;
1749 struct sk_buff *skb;
1750
1751 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1752 flags & MSG_DONTWAIT, &err);
1753 lock_sock(sk);
1754
1755 if (!skb)
1756 goto out;
1757
1758 /* FIXME: use skb->cb to be able to use shared skbs */
1759 ddp = ddp_hdr(skb);
1760 copied = ntohs(ddp->deh_len_hops) & 1023;
1761
1762 if (sk->sk_type != SOCK_RAW) {
1763 offset = sizeof(*ddp);
1764 copied -= offset;
1765 }
1766
1767 if (copied > size) {
1768 copied = size;
1769 msg->msg_flags |= MSG_TRUNC;
1770 }
1771 err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1772
1773 if (!err) {
1774 if (sat) {
1775 sat->sat_family = AF_APPLETALK;
1776 sat->sat_port = ddp->deh_sport;
1777 sat->sat_addr.s_node = ddp->deh_snode;
1778 sat->sat_addr.s_net = ddp->deh_snet;
1779 }
1780 msg->msg_namelen = sizeof(*sat);
1781 }
1782
1783 skb_free_datagram(sk, skb); /* Free the datagram. */
1784
1785 out:
1786 release_sock(sk);
1787 return err ? : copied;
1788 }
1789
1790
1791 /*
1792 * AppleTalk ioctl calls.
1793 */
atalk_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1794 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1795 {
1796 int rc = -ENOIOCTLCMD;
1797 struct sock *sk = sock->sk;
1798 void __user *argp = (void __user *)arg;
1799
1800 switch (cmd) {
1801 /* Protocol layer */
1802 case TIOCOUTQ: {
1803 long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1804
1805 if (amount < 0)
1806 amount = 0;
1807 rc = put_user(amount, (int __user *)argp);
1808 break;
1809 }
1810 case TIOCINQ: {
1811 /*
1812 * These two are safe on a single CPU system as only
1813 * user tasks fiddle here
1814 */
1815 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1816 long amount = 0;
1817
1818 if (skb)
1819 amount = skb->len - sizeof(struct ddpehdr);
1820 rc = put_user(amount, (int __user *)argp);
1821 break;
1822 }
1823 case SIOCGSTAMP:
1824 rc = sock_get_timestamp(sk, argp);
1825 break;
1826 case SIOCGSTAMPNS:
1827 rc = sock_get_timestampns(sk, argp);
1828 break;
1829 /* Routing */
1830 case SIOCADDRT:
1831 case SIOCDELRT:
1832 rc = -EPERM;
1833 if (capable(CAP_NET_ADMIN))
1834 rc = atrtr_ioctl(cmd, argp);
1835 break;
1836 /* Interface */
1837 case SIOCGIFADDR:
1838 case SIOCSIFADDR:
1839 case SIOCGIFBRDADDR:
1840 case SIOCATALKDIFADDR:
1841 case SIOCDIFADDR:
1842 case SIOCSARP: /* proxy AARP */
1843 case SIOCDARP: /* proxy AARP */
1844 rtnl_lock();
1845 rc = atif_ioctl(cmd, argp);
1846 rtnl_unlock();
1847 break;
1848 }
1849
1850 return rc;
1851 }
1852
1853
1854 #ifdef CONFIG_COMPAT
atalk_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1855 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1856 {
1857 /*
1858 * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1859 * cannot handle it in common code. The data we access if ifreq
1860 * here is compatible, so we can simply call the native
1861 * handler.
1862 */
1863 if (cmd == SIOCATALKDIFADDR)
1864 return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1865
1866 return -ENOIOCTLCMD;
1867 }
1868 #endif
1869
1870
1871 static const struct net_proto_family atalk_family_ops = {
1872 .family = PF_APPLETALK,
1873 .create = atalk_create,
1874 .owner = THIS_MODULE,
1875 };
1876
1877 static const struct proto_ops atalk_dgram_ops = {
1878 .family = PF_APPLETALK,
1879 .owner = THIS_MODULE,
1880 .release = atalk_release,
1881 .bind = atalk_bind,
1882 .connect = atalk_connect,
1883 .socketpair = sock_no_socketpair,
1884 .accept = sock_no_accept,
1885 .getname = atalk_getname,
1886 .poll = datagram_poll,
1887 .ioctl = atalk_ioctl,
1888 #ifdef CONFIG_COMPAT
1889 .compat_ioctl = atalk_compat_ioctl,
1890 #endif
1891 .listen = sock_no_listen,
1892 .shutdown = sock_no_shutdown,
1893 .setsockopt = sock_no_setsockopt,
1894 .getsockopt = sock_no_getsockopt,
1895 .sendmsg = atalk_sendmsg,
1896 .recvmsg = atalk_recvmsg,
1897 .mmap = sock_no_mmap,
1898 .sendpage = sock_no_sendpage,
1899 };
1900
1901 static struct notifier_block ddp_notifier = {
1902 .notifier_call = ddp_device_event,
1903 };
1904
1905 static struct packet_type ltalk_packet_type __read_mostly = {
1906 .type = cpu_to_be16(ETH_P_LOCALTALK),
1907 .func = ltalk_rcv,
1908 };
1909
1910 static struct packet_type ppptalk_packet_type __read_mostly = {
1911 .type = cpu_to_be16(ETH_P_PPPTALK),
1912 .func = atalk_rcv,
1913 };
1914
1915 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1916
1917 /* Export symbols for use by drivers when AppleTalk is a module */
1918 EXPORT_SYMBOL(atrtr_get_dev);
1919 EXPORT_SYMBOL(atalk_find_dev_addr);
1920
1921 static const char atalk_err_snap[] __initconst =
1922 KERN_CRIT "Unable to register DDP with SNAP.\n";
1923
1924 /* Called by proto.c on kernel start up */
atalk_init(void)1925 static int __init atalk_init(void)
1926 {
1927 int rc = proto_register(&ddp_proto, 0);
1928
1929 if (rc != 0)
1930 goto out;
1931
1932 (void)sock_register(&atalk_family_ops);
1933 ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1934 if (!ddp_dl)
1935 printk(atalk_err_snap);
1936
1937 dev_add_pack(<alk_packet_type);
1938 dev_add_pack(&ppptalk_packet_type);
1939
1940 register_netdevice_notifier(&ddp_notifier);
1941 aarp_proto_init();
1942 atalk_proc_init();
1943 atalk_register_sysctl();
1944 out:
1945 return rc;
1946 }
1947 module_init(atalk_init);
1948
1949 /*
1950 * No explicit module reference count manipulation is needed in the
1951 * protocol. Socket layer sets module reference count for us
1952 * and interfaces reference counting is done
1953 * by the network device layer.
1954 *
1955 * Ergo, before the AppleTalk module can be removed, all AppleTalk
1956 * sockets be closed from user space.
1957 */
atalk_exit(void)1958 static void __exit atalk_exit(void)
1959 {
1960 #ifdef CONFIG_SYSCTL
1961 atalk_unregister_sysctl();
1962 #endif /* CONFIG_SYSCTL */
1963 atalk_proc_exit();
1964 aarp_cleanup_module(); /* General aarp clean-up. */
1965 unregister_netdevice_notifier(&ddp_notifier);
1966 dev_remove_pack(<alk_packet_type);
1967 dev_remove_pack(&ppptalk_packet_type);
1968 unregister_snap_client(ddp_dl);
1969 sock_unregister(PF_APPLETALK);
1970 proto_unregister(&ddp_proto);
1971 }
1972 module_exit(atalk_exit);
1973
1974 MODULE_LICENSE("GPL");
1975 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1976 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1977 MODULE_ALIAS_NETPROTO(PF_APPLETALK);
1978