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 <net/datalink.h>
59 #include <net/psnap.h>
60 #include <net/sock.h>
61 #include <net/tcp_states.h>
62 #include <net/route.h>
63 #include <linux/atalk.h>
64 #include "../core/kmap_skb.h"
65
66 struct datalink_proto *ddp_dl, *aarp_dl;
67 static const struct proto_ops atalk_dgram_ops;
68
69 /**************************************************************************\
70 * *
71 * Handlers for the socket list. *
72 * *
73 \**************************************************************************/
74
75 HLIST_HEAD(atalk_sockets);
76 DEFINE_RWLOCK(atalk_sockets_lock);
77
__atalk_insert_socket(struct sock * sk)78 static inline void __atalk_insert_socket(struct sock *sk)
79 {
80 sk_add_node(sk, &atalk_sockets);
81 }
82
atalk_remove_socket(struct sock * sk)83 static inline void atalk_remove_socket(struct sock *sk)
84 {
85 write_lock_bh(&atalk_sockets_lock);
86 sk_del_node_init(sk);
87 write_unlock_bh(&atalk_sockets_lock);
88 }
89
atalk_search_socket(struct sockaddr_at * to,struct atalk_iface * atif)90 static struct sock *atalk_search_socket(struct sockaddr_at *to,
91 struct atalk_iface *atif)
92 {
93 struct sock *s;
94 struct hlist_node *node;
95
96 read_lock_bh(&atalk_sockets_lock);
97 sk_for_each(s, node, &atalk_sockets) {
98 struct atalk_sock *at = at_sk(s);
99
100 if (to->sat_port != at->src_port)
101 continue;
102
103 if (to->sat_addr.s_net == ATADDR_ANYNET &&
104 to->sat_addr.s_node == ATADDR_BCAST)
105 goto found;
106
107 if (to->sat_addr.s_net == at->src_net &&
108 (to->sat_addr.s_node == at->src_node ||
109 to->sat_addr.s_node == ATADDR_BCAST ||
110 to->sat_addr.s_node == ATADDR_ANYNODE))
111 goto found;
112
113 /* XXXX.0 -- we got a request for this router. make sure
114 * that the node is appropriately set. */
115 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
116 to->sat_addr.s_net != ATADDR_ANYNET &&
117 atif->address.s_node == at->src_node) {
118 to->sat_addr.s_node = atif->address.s_node;
119 goto found;
120 }
121 }
122 s = NULL;
123 found:
124 read_unlock_bh(&atalk_sockets_lock);
125 return s;
126 }
127
128 /**
129 * atalk_find_or_insert_socket - Try to find a socket matching ADDR
130 * @sk - socket to insert in the list if it is not there already
131 * @sat - address to search for
132 *
133 * Try to find a socket matching ADDR in the socket list, if found then return
134 * it. If not, insert SK into the socket list.
135 *
136 * This entire operation must execute atomically.
137 */
atalk_find_or_insert_socket(struct sock * sk,struct sockaddr_at * sat)138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
139 struct sockaddr_at *sat)
140 {
141 struct sock *s;
142 struct hlist_node *node;
143 struct atalk_sock *at;
144
145 write_lock_bh(&atalk_sockets_lock);
146 sk_for_each(s, node, &atalk_sockets) {
147 at = at_sk(s);
148
149 if (at->src_net == sat->sat_addr.s_net &&
150 at->src_node == sat->sat_addr.s_node &&
151 at->src_port == sat->sat_port)
152 goto found;
153 }
154 s = NULL;
155 __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
156 found:
157 write_unlock_bh(&atalk_sockets_lock);
158 return s;
159 }
160
atalk_destroy_timer(unsigned long data)161 static void atalk_destroy_timer(unsigned long data)
162 {
163 struct sock *sk = (struct sock *)data;
164
165 if (atomic_read(&sk->sk_wmem_alloc) ||
166 atomic_read(&sk->sk_rmem_alloc)) {
167 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
168 add_timer(&sk->sk_timer);
169 } else
170 sock_put(sk);
171 }
172
atalk_destroy_socket(struct sock * sk)173 static inline void atalk_destroy_socket(struct sock *sk)
174 {
175 atalk_remove_socket(sk);
176 skb_queue_purge(&sk->sk_receive_queue);
177
178 if (atomic_read(&sk->sk_wmem_alloc) ||
179 atomic_read(&sk->sk_rmem_alloc)) {
180 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(dev, aarp_mcast, 6, 1);
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 <<= 1;
928 if (sum & 0x10000) {
929 sum++;
930 sum &= 0xffff;
931 }
932 data++;
933 }
934 return sum;
935 }
936
937 /* Checksum skb data -- similar to skb_checksum */
atalk_sum_skb(const struct sk_buff * skb,int offset,int len,unsigned long sum)938 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
939 int len, unsigned long sum)
940 {
941 int start = skb_headlen(skb);
942 int i, copy;
943
944 /* checksum stuff in header space */
945 if ( (copy = start - offset) > 0) {
946 if (copy > len)
947 copy = len;
948 sum = atalk_sum_partial(skb->data + offset, copy, sum);
949 if ( (len -= copy) == 0)
950 return sum;
951
952 offset += copy;
953 }
954
955 /* checksum stuff in frags */
956 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
957 int end;
958
959 WARN_ON(start > offset + len);
960
961 end = start + skb_shinfo(skb)->frags[i].size;
962 if ((copy = end - offset) > 0) {
963 u8 *vaddr;
964 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
965
966 if (copy > len)
967 copy = len;
968 vaddr = kmap_skb_frag(frag);
969 sum = atalk_sum_partial(vaddr + frag->page_offset +
970 offset - start, copy, sum);
971 kunmap_skb_frag(vaddr);
972
973 if (!(len -= copy))
974 return sum;
975 offset += copy;
976 }
977 start = end;
978 }
979
980 if (skb_shinfo(skb)->frag_list) {
981 struct sk_buff *list = skb_shinfo(skb)->frag_list;
982
983 for (; list; list = list->next) {
984 int end;
985
986 WARN_ON(start > offset + len);
987
988 end = start + list->len;
989 if ((copy = end - offset) > 0) {
990 if (copy > len)
991 copy = len;
992 sum = atalk_sum_skb(list, offset - start,
993 copy, sum);
994 if ((len -= copy) == 0)
995 return sum;
996 offset += copy;
997 }
998 start = end;
999 }
1000 }
1001
1002 BUG_ON(len > 0);
1003
1004 return sum;
1005 }
1006
atalk_checksum(const struct sk_buff * skb,int len)1007 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1008 {
1009 unsigned long sum;
1010
1011 /* skip header 4 bytes */
1012 sum = atalk_sum_skb(skb, 4, len-4, 0);
1013
1014 /* Use 0xFFFF for 0. 0 itself means none */
1015 return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1016 }
1017
1018 static struct proto ddp_proto = {
1019 .name = "DDP",
1020 .owner = THIS_MODULE,
1021 .obj_size = sizeof(struct atalk_sock),
1022 };
1023
1024 /*
1025 * Create a socket. Initialise the socket, blank the addresses
1026 * set the state.
1027 */
atalk_create(struct net * net,struct socket * sock,int protocol)1028 static int atalk_create(struct net *net, struct socket *sock, int protocol)
1029 {
1030 struct sock *sk;
1031 int rc = -ESOCKTNOSUPPORT;
1032
1033 if (net != &init_net)
1034 return -EAFNOSUPPORT;
1035
1036 /*
1037 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1038 * and gives you the full ELAP frame. Should be handy for CAP 8)
1039 */
1040 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1041 goto out;
1042 rc = -ENOMEM;
1043 sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1044 if (!sk)
1045 goto out;
1046 rc = 0;
1047 sock->ops = &atalk_dgram_ops;
1048 sock_init_data(sock, sk);
1049
1050 /* Checksums on by default */
1051 sock_set_flag(sk, SOCK_ZAPPED);
1052 out:
1053 return rc;
1054 }
1055
1056 /* Free a socket. No work needed */
atalk_release(struct socket * sock)1057 static int atalk_release(struct socket *sock)
1058 {
1059 struct sock *sk = sock->sk;
1060
1061 if (sk) {
1062 sock_orphan(sk);
1063 sock->sk = NULL;
1064 atalk_destroy_socket(sk);
1065 }
1066 return 0;
1067 }
1068
1069 /**
1070 * atalk_pick_and_bind_port - Pick a source port when one is not given
1071 * @sk - socket to insert into the tables
1072 * @sat - address to search for
1073 *
1074 * Pick a source port when one is not given. If we can find a suitable free
1075 * one, we insert the socket into the tables using it.
1076 *
1077 * This whole operation must be atomic.
1078 */
atalk_pick_and_bind_port(struct sock * sk,struct sockaddr_at * sat)1079 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1080 {
1081 int retval;
1082
1083 write_lock_bh(&atalk_sockets_lock);
1084
1085 for (sat->sat_port = ATPORT_RESERVED;
1086 sat->sat_port < ATPORT_LAST;
1087 sat->sat_port++) {
1088 struct sock *s;
1089 struct hlist_node *node;
1090
1091 sk_for_each(s, node, &atalk_sockets) {
1092 struct atalk_sock *at = at_sk(s);
1093
1094 if (at->src_net == sat->sat_addr.s_net &&
1095 at->src_node == sat->sat_addr.s_node &&
1096 at->src_port == sat->sat_port)
1097 goto try_next_port;
1098 }
1099
1100 /* Wheee, it's free, assign and insert. */
1101 __atalk_insert_socket(sk);
1102 at_sk(sk)->src_port = sat->sat_port;
1103 retval = 0;
1104 goto out;
1105
1106 try_next_port:;
1107 }
1108
1109 retval = -EBUSY;
1110 out:
1111 write_unlock_bh(&atalk_sockets_lock);
1112 return retval;
1113 }
1114
atalk_autobind(struct sock * sk)1115 static int atalk_autobind(struct sock *sk)
1116 {
1117 struct atalk_sock *at = at_sk(sk);
1118 struct sockaddr_at sat;
1119 struct atalk_addr *ap = atalk_find_primary();
1120 int n = -EADDRNOTAVAIL;
1121
1122 if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1123 goto out;
1124
1125 at->src_net = sat.sat_addr.s_net = ap->s_net;
1126 at->src_node = sat.sat_addr.s_node = ap->s_node;
1127
1128 n = atalk_pick_and_bind_port(sk, &sat);
1129 if (!n)
1130 sock_reset_flag(sk, SOCK_ZAPPED);
1131 out:
1132 return n;
1133 }
1134
1135 /* Set the address 'our end' of the connection */
atalk_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)1136 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1137 {
1138 struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1139 struct sock *sk = sock->sk;
1140 struct atalk_sock *at = at_sk(sk);
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 if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1150 struct atalk_addr *ap = atalk_find_primary();
1151
1152 if (!ap)
1153 return -EADDRNOTAVAIL;
1154
1155 at->src_net = addr->sat_addr.s_net = ap->s_net;
1156 at->src_node = addr->sat_addr.s_node= ap->s_node;
1157 } else {
1158 if (!atalk_find_interface(addr->sat_addr.s_net,
1159 addr->sat_addr.s_node))
1160 return -EADDRNOTAVAIL;
1161
1162 at->src_net = addr->sat_addr.s_net;
1163 at->src_node = addr->sat_addr.s_node;
1164 }
1165
1166 if (addr->sat_port == ATADDR_ANYPORT) {
1167 int n = atalk_pick_and_bind_port(sk, addr);
1168
1169 if (n < 0)
1170 return n;
1171 } else {
1172 at->src_port = addr->sat_port;
1173
1174 if (atalk_find_or_insert_socket(sk, addr))
1175 return -EADDRINUSE;
1176 }
1177
1178 sock_reset_flag(sk, SOCK_ZAPPED);
1179 return 0;
1180 }
1181
1182 /* Set the address we talk to */
atalk_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)1183 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1184 int addr_len, int flags)
1185 {
1186 struct sock *sk = sock->sk;
1187 struct atalk_sock *at = at_sk(sk);
1188 struct sockaddr_at *addr;
1189
1190 sk->sk_state = TCP_CLOSE;
1191 sock->state = SS_UNCONNECTED;
1192
1193 if (addr_len != sizeof(*addr))
1194 return -EINVAL;
1195
1196 addr = (struct sockaddr_at *)uaddr;
1197
1198 if (addr->sat_family != AF_APPLETALK)
1199 return -EAFNOSUPPORT;
1200
1201 if (addr->sat_addr.s_node == ATADDR_BCAST &&
1202 !sock_flag(sk, SOCK_BROADCAST)) {
1203 #if 1
1204 printk(KERN_WARNING "%s is broken and did not set "
1205 "SO_BROADCAST. It will break when 2.2 is "
1206 "released.\n",
1207 current->comm);
1208 #else
1209 return -EACCES;
1210 #endif
1211 }
1212
1213 if (sock_flag(sk, SOCK_ZAPPED))
1214 if (atalk_autobind(sk) < 0)
1215 return -EBUSY;
1216
1217 if (!atrtr_get_dev(&addr->sat_addr))
1218 return -ENETUNREACH;
1219
1220 at->dest_port = addr->sat_port;
1221 at->dest_net = addr->sat_addr.s_net;
1222 at->dest_node = addr->sat_addr.s_node;
1223
1224 sock->state = SS_CONNECTED;
1225 sk->sk_state = TCP_ESTABLISHED;
1226 return 0;
1227 }
1228
1229 /*
1230 * Find the name of an AppleTalk socket. Just copy the right
1231 * fields into the sockaddr.
1232 */
atalk_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)1233 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1234 int *uaddr_len, int peer)
1235 {
1236 struct sockaddr_at sat;
1237 struct sock *sk = sock->sk;
1238 struct atalk_sock *at = at_sk(sk);
1239
1240 if (sock_flag(sk, SOCK_ZAPPED))
1241 if (atalk_autobind(sk) < 0)
1242 return -ENOBUFS;
1243
1244 *uaddr_len = sizeof(struct sockaddr_at);
1245
1246 if (peer) {
1247 if (sk->sk_state != TCP_ESTABLISHED)
1248 return -ENOTCONN;
1249
1250 sat.sat_addr.s_net = at->dest_net;
1251 sat.sat_addr.s_node = at->dest_node;
1252 sat.sat_port = at->dest_port;
1253 } else {
1254 sat.sat_addr.s_net = at->src_net;
1255 sat.sat_addr.s_node = at->src_node;
1256 sat.sat_port = at->src_port;
1257 }
1258
1259 sat.sat_family = AF_APPLETALK;
1260 memcpy(uaddr, &sat, sizeof(sat));
1261 return 0;
1262 }
1263
1264 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
is_ip_over_ddp(struct sk_buff * skb)1265 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1266 {
1267 return skb->data[12] == 22;
1268 }
1269
handle_ip_over_ddp(struct sk_buff * skb)1270 static int handle_ip_over_ddp(struct sk_buff *skb)
1271 {
1272 struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1273 struct net_device_stats *stats;
1274
1275 /* This needs to be able to handle ipddp"N" devices */
1276 if (!dev)
1277 return -ENODEV;
1278
1279 skb->protocol = htons(ETH_P_IP);
1280 skb_pull(skb, 13);
1281 skb->dev = dev;
1282 skb_reset_transport_header(skb);
1283
1284 stats = netdev_priv(dev);
1285 stats->rx_packets++;
1286 stats->rx_bytes += skb->len + 13;
1287 netif_rx(skb); /* Send the SKB up to a higher place. */
1288 return 0;
1289 }
1290 #else
1291 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1292 #define is_ip_over_ddp(skb) 0
1293 #define handle_ip_over_ddp(skb) 0
1294 #endif
1295
atalk_route_packet(struct sk_buff * skb,struct net_device * dev,struct ddpehdr * ddp,__u16 len_hops,int origlen)1296 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1297 struct ddpehdr *ddp, __u16 len_hops,
1298 int origlen)
1299 {
1300 struct atalk_route *rt;
1301 struct atalk_addr ta;
1302
1303 /*
1304 * Don't route multicast, etc., packets, or packets sent to "this
1305 * network"
1306 */
1307 if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1308 /*
1309 * FIXME:
1310 *
1311 * Can it ever happen that a packet is from a PPP iface and
1312 * needs to be broadcast onto the default network?
1313 */
1314 if (dev->type == ARPHRD_PPP)
1315 printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1316 "packet received from PPP iface\n");
1317 goto free_it;
1318 }
1319
1320 ta.s_net = ddp->deh_dnet;
1321 ta.s_node = ddp->deh_dnode;
1322
1323 /* Route the packet */
1324 rt = atrtr_find(&ta);
1325 /* increment hops count */
1326 len_hops += 1 << 10;
1327 if (!rt || !(len_hops & (15 << 10)))
1328 goto free_it;
1329
1330 /* FIXME: use skb->cb to be able to use shared skbs */
1331
1332 /*
1333 * Route goes through another gateway, so set the target to the
1334 * gateway instead.
1335 */
1336
1337 if (rt->flags & RTF_GATEWAY) {
1338 ta.s_net = rt->gateway.s_net;
1339 ta.s_node = rt->gateway.s_node;
1340 }
1341
1342 /* Fix up skb->len field */
1343 skb_trim(skb, min_t(unsigned int, origlen,
1344 (rt->dev->hard_header_len +
1345 ddp_dl->header_length + (len_hops & 1023))));
1346
1347 /* FIXME: use skb->cb to be able to use shared skbs */
1348 ddp->deh_len_hops = htons(len_hops);
1349
1350 /*
1351 * Send the buffer onwards
1352 *
1353 * Now we must always be careful. If it's come from LocalTalk to
1354 * EtherTalk it might not fit
1355 *
1356 * Order matters here: If a packet has to be copied to make a new
1357 * headroom (rare hopefully) then it won't need unsharing.
1358 *
1359 * Note. ddp-> becomes invalid at the realloc.
1360 */
1361 if (skb_headroom(skb) < 22) {
1362 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1363 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1364 kfree_skb(skb);
1365 if (!nskb)
1366 goto out;
1367 skb = nskb;
1368 } else
1369 skb = skb_unshare(skb, GFP_ATOMIC);
1370
1371 /*
1372 * If the buffer didn't vanish into the lack of space bitbucket we can
1373 * send it.
1374 */
1375 if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1376 goto free_it;
1377 out:
1378 return;
1379 free_it:
1380 kfree_skb(skb);
1381 }
1382
1383 /**
1384 * atalk_rcv - Receive a packet (in skb) from device dev
1385 * @skb - packet received
1386 * @dev - network device where the packet comes from
1387 * @pt - packet type
1388 *
1389 * Receive a packet (in skb) from device dev. This has come from the SNAP
1390 * decoder, and on entry skb->transport_header is the DDP header, skb->len
1391 * is the DDP header, skb->len is the DDP length. The physical headers
1392 * have been extracted. PPP should probably pass frames marked as for this
1393 * layer. [ie ARPHRD_ETHERTALK]
1394 */
atalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1395 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1396 struct packet_type *pt, struct net_device *orig_dev)
1397 {
1398 struct ddpehdr *ddp;
1399 struct sock *sock;
1400 struct atalk_iface *atif;
1401 struct sockaddr_at tosat;
1402 int origlen;
1403 __u16 len_hops;
1404
1405 if (!net_eq(dev_net(dev), &init_net))
1406 goto freeit;
1407
1408 /* Don't mangle buffer if shared */
1409 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1410 goto out;
1411
1412 /* Size check and make sure header is contiguous */
1413 if (!pskb_may_pull(skb, sizeof(*ddp)))
1414 goto freeit;
1415
1416 ddp = ddp_hdr(skb);
1417
1418 len_hops = ntohs(ddp->deh_len_hops);
1419
1420 /* Trim buffer in case of stray trailing data */
1421 origlen = skb->len;
1422 skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1423
1424 /*
1425 * Size check to see if ddp->deh_len was crap
1426 * (Otherwise we'll detonate most spectacularly
1427 * in the middle of atalk_checksum() or recvmsg()).
1428 */
1429 if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1430 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1431 "skb->len=%u)\n", len_hops & 1023, skb->len);
1432 goto freeit;
1433 }
1434
1435 /*
1436 * Any checksums. Note we don't do htons() on this == is assumed to be
1437 * valid for net byte orders all over the networking code...
1438 */
1439 if (ddp->deh_sum &&
1440 atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1441 /* Not a valid AppleTalk frame - dustbin time */
1442 goto freeit;
1443
1444 /* Check the packet is aimed at us */
1445 if (!ddp->deh_dnet) /* Net 0 is 'this network' */
1446 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1447 else
1448 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1449
1450 if (!atif) {
1451 /* Not ours, so we route the packet via the correct
1452 * AppleTalk iface
1453 */
1454 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1455 goto out;
1456 }
1457
1458 /* if IP over DDP is not selected this code will be optimized out */
1459 if (is_ip_over_ddp(skb))
1460 return handle_ip_over_ddp(skb);
1461 /*
1462 * Which socket - atalk_search_socket() looks for a *full match*
1463 * of the <net, node, port> tuple.
1464 */
1465 tosat.sat_addr.s_net = ddp->deh_dnet;
1466 tosat.sat_addr.s_node = ddp->deh_dnode;
1467 tosat.sat_port = ddp->deh_dport;
1468
1469 sock = atalk_search_socket(&tosat, atif);
1470 if (!sock) /* But not one of our sockets */
1471 goto freeit;
1472
1473 /* Queue packet (standard) */
1474 skb->sk = sock;
1475
1476 if (sock_queue_rcv_skb(sock, skb) < 0)
1477 goto freeit;
1478 out:
1479 return 0;
1480 freeit:
1481 kfree_skb(skb);
1482 goto out;
1483 }
1484
1485 /*
1486 * Receive a LocalTalk frame. We make some demands on the caller here.
1487 * Caller must provide enough headroom on the packet to pull the short
1488 * header and append a long one.
1489 */
ltalk_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)1490 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1491 struct packet_type *pt, struct net_device *orig_dev)
1492 {
1493 if (!net_eq(dev_net(dev), &init_net))
1494 goto freeit;
1495
1496 /* Expand any short form frames */
1497 if (skb_mac_header(skb)[2] == 1) {
1498 struct ddpehdr *ddp;
1499 /* Find our address */
1500 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1501
1502 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1503 goto freeit;
1504
1505 /* Don't mangle buffer if shared */
1506 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1507 return 0;
1508
1509 /*
1510 * The push leaves us with a ddephdr not an shdr, and
1511 * handily the port bytes in the right place preset.
1512 */
1513 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1514
1515 /* Now fill in the long header */
1516
1517 /*
1518 * These two first. The mac overlays the new source/dest
1519 * network information so we MUST copy these before
1520 * we write the network numbers !
1521 */
1522
1523 ddp->deh_dnode = skb_mac_header(skb)[0]; /* From physical header */
1524 ddp->deh_snode = skb_mac_header(skb)[1]; /* From physical header */
1525
1526 ddp->deh_dnet = ap->s_net; /* Network number */
1527 ddp->deh_snet = ap->s_net;
1528 ddp->deh_sum = 0; /* No checksum */
1529 /*
1530 * Not sure about this bit...
1531 */
1532 /* Non routable, so force a drop if we slip up later */
1533 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1534 }
1535 skb_reset_transport_header(skb);
1536
1537 return atalk_rcv(skb, dev, pt, orig_dev);
1538 freeit:
1539 kfree_skb(skb);
1540 return 0;
1541 }
1542
atalk_sendmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t len)1543 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1544 size_t len)
1545 {
1546 struct sock *sk = sock->sk;
1547 struct atalk_sock *at = at_sk(sk);
1548 struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1549 int flags = msg->msg_flags;
1550 int loopback = 0;
1551 struct sockaddr_at local_satalk, gsat;
1552 struct sk_buff *skb;
1553 struct net_device *dev;
1554 struct ddpehdr *ddp;
1555 int size;
1556 struct atalk_route *rt;
1557 int err;
1558
1559 if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1560 return -EINVAL;
1561
1562 if (len > DDP_MAXSZ)
1563 return -EMSGSIZE;
1564
1565 if (usat) {
1566 if (sock_flag(sk, SOCK_ZAPPED))
1567 if (atalk_autobind(sk) < 0)
1568 return -EBUSY;
1569
1570 if (msg->msg_namelen < sizeof(*usat) ||
1571 usat->sat_family != AF_APPLETALK)
1572 return -EINVAL;
1573
1574 /* netatalk doesn't implement this check */
1575 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1576 !sock_flag(sk, SOCK_BROADCAST)) {
1577 printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1578 "it will break before 2.2\n");
1579 #if 0
1580 return -EPERM;
1581 #endif
1582 }
1583 } else {
1584 if (sk->sk_state != TCP_ESTABLISHED)
1585 return -ENOTCONN;
1586 usat = &local_satalk;
1587 usat->sat_family = AF_APPLETALK;
1588 usat->sat_port = at->dest_port;
1589 usat->sat_addr.s_node = at->dest_node;
1590 usat->sat_addr.s_net = at->dest_net;
1591 }
1592
1593 /* Build a packet */
1594 SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1595
1596 /* For headers */
1597 size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1598
1599 if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1600 rt = atrtr_find(&usat->sat_addr);
1601 } else {
1602 struct atalk_addr at_hint;
1603
1604 at_hint.s_node = 0;
1605 at_hint.s_net = at->src_net;
1606
1607 rt = atrtr_find(&at_hint);
1608 }
1609 if (!rt)
1610 return -ENETUNREACH;
1611
1612 dev = rt->dev;
1613
1614 SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1615 sk, size, dev->name);
1616
1617 size += dev->hard_header_len;
1618 skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1619 if (!skb)
1620 return err;
1621
1622 skb->sk = sk;
1623 skb_reserve(skb, ddp_dl->header_length);
1624 skb_reserve(skb, dev->hard_header_len);
1625 skb->dev = dev;
1626
1627 SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1628
1629 ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1630 ddp->deh_len_hops = htons(len + sizeof(*ddp));
1631 ddp->deh_dnet = usat->sat_addr.s_net;
1632 ddp->deh_snet = at->src_net;
1633 ddp->deh_dnode = usat->sat_addr.s_node;
1634 ddp->deh_snode = at->src_node;
1635 ddp->deh_dport = usat->sat_port;
1636 ddp->deh_sport = at->src_port;
1637
1638 SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1639
1640 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1641 if (err) {
1642 kfree_skb(skb);
1643 return -EFAULT;
1644 }
1645
1646 if (sk->sk_no_check == 1)
1647 ddp->deh_sum = 0;
1648 else
1649 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1650
1651 /*
1652 * Loopback broadcast packets to non gateway targets (ie routes
1653 * to group we are in)
1654 */
1655 if (ddp->deh_dnode == ATADDR_BCAST &&
1656 !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1657 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1658
1659 if (skb2) {
1660 loopback = 1;
1661 SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1662 if (aarp_send_ddp(dev, skb2,
1663 &usat->sat_addr, NULL) == -1)
1664 kfree_skb(skb2);
1665 /* else queued/sent above in the aarp queue */
1666 }
1667 }
1668
1669 if (dev->flags & IFF_LOOPBACK || loopback) {
1670 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1671 /* loop back */
1672 skb_orphan(skb);
1673 if (ddp->deh_dnode == ATADDR_BCAST) {
1674 struct atalk_addr at_lo;
1675
1676 at_lo.s_node = 0;
1677 at_lo.s_net = 0;
1678
1679 rt = atrtr_find(&at_lo);
1680 if (!rt) {
1681 kfree_skb(skb);
1682 return -ENETUNREACH;
1683 }
1684 dev = rt->dev;
1685 skb->dev = dev;
1686 }
1687 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1688 } else {
1689 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1690 if (rt->flags & RTF_GATEWAY) {
1691 gsat.sat_addr = rt->gateway;
1692 usat = &gsat;
1693 }
1694
1695 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1696 kfree_skb(skb);
1697 /* else queued/sent above in the aarp queue */
1698 }
1699 SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1700
1701 return len;
1702 }
1703
atalk_recvmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size,int flags)1704 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1705 size_t size, int flags)
1706 {
1707 struct sock *sk = sock->sk;
1708 struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1709 struct ddpehdr *ddp;
1710 int copied = 0;
1711 int offset = 0;
1712 int err = 0;
1713 struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1714 flags & MSG_DONTWAIT, &err);
1715 if (!skb)
1716 return err;
1717
1718 /* FIXME: use skb->cb to be able to use shared skbs */
1719 ddp = ddp_hdr(skb);
1720 copied = ntohs(ddp->deh_len_hops) & 1023;
1721
1722 if (sk->sk_type != SOCK_RAW) {
1723 offset = sizeof(*ddp);
1724 copied -= offset;
1725 }
1726
1727 if (copied > size) {
1728 copied = size;
1729 msg->msg_flags |= MSG_TRUNC;
1730 }
1731 err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
1732
1733 if (!err) {
1734 if (sat) {
1735 sat->sat_family = AF_APPLETALK;
1736 sat->sat_port = ddp->deh_sport;
1737 sat->sat_addr.s_node = ddp->deh_snode;
1738 sat->sat_addr.s_net = ddp->deh_snet;
1739 }
1740 msg->msg_namelen = sizeof(*sat);
1741 }
1742
1743 skb_free_datagram(sk, skb); /* Free the datagram. */
1744 return err ? : copied;
1745 }
1746
1747
1748 /*
1749 * AppleTalk ioctl calls.
1750 */
atalk_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1751 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1752 {
1753 int rc = -ENOIOCTLCMD;
1754 struct sock *sk = sock->sk;
1755 void __user *argp = (void __user *)arg;
1756
1757 switch (cmd) {
1758 /* Protocol layer */
1759 case TIOCOUTQ: {
1760 long amount = sk->sk_sndbuf -
1761 atomic_read(&sk->sk_wmem_alloc);
1762
1763 if (amount < 0)
1764 amount = 0;
1765 rc = put_user(amount, (int __user *)argp);
1766 break;
1767 }
1768 case TIOCINQ: {
1769 /*
1770 * These two are safe on a single CPU system as only
1771 * user tasks fiddle here
1772 */
1773 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1774 long amount = 0;
1775
1776 if (skb)
1777 amount = skb->len - sizeof(struct ddpehdr);
1778 rc = put_user(amount, (int __user *)argp);
1779 break;
1780 }
1781 case SIOCGSTAMP:
1782 rc = sock_get_timestamp(sk, argp);
1783 break;
1784 case SIOCGSTAMPNS:
1785 rc = sock_get_timestampns(sk, argp);
1786 break;
1787 /* Routing */
1788 case SIOCADDRT:
1789 case SIOCDELRT:
1790 rc = -EPERM;
1791 if (capable(CAP_NET_ADMIN))
1792 rc = atrtr_ioctl(cmd, argp);
1793 break;
1794 /* Interface */
1795 case SIOCGIFADDR:
1796 case SIOCSIFADDR:
1797 case SIOCGIFBRDADDR:
1798 case SIOCATALKDIFADDR:
1799 case SIOCDIFADDR:
1800 case SIOCSARP: /* proxy AARP */
1801 case SIOCDARP: /* proxy AARP */
1802 rtnl_lock();
1803 rc = atif_ioctl(cmd, argp);
1804 rtnl_unlock();
1805 break;
1806 }
1807
1808 return rc;
1809 }
1810
1811
1812 #ifdef CONFIG_COMPAT
atalk_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1813 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1814 {
1815 /*
1816 * All Appletalk ioctls except SIOCATALKDIFADDR are standard. And
1817 * SIOCATALKDIFADDR is handled by upper layer as well, so there is
1818 * nothing to do. Eventually SIOCATALKDIFADDR should be moved
1819 * here so there is no generic SIOCPROTOPRIVATE translation in the
1820 * system.
1821 */
1822 return -ENOIOCTLCMD;
1823 }
1824 #endif
1825
1826
1827 static struct net_proto_family atalk_family_ops = {
1828 .family = PF_APPLETALK,
1829 .create = atalk_create,
1830 .owner = THIS_MODULE,
1831 };
1832
1833 static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1834 .family = PF_APPLETALK,
1835 .owner = THIS_MODULE,
1836 .release = atalk_release,
1837 .bind = atalk_bind,
1838 .connect = atalk_connect,
1839 .socketpair = sock_no_socketpair,
1840 .accept = sock_no_accept,
1841 .getname = atalk_getname,
1842 .poll = datagram_poll,
1843 .ioctl = atalk_ioctl,
1844 #ifdef CONFIG_COMPAT
1845 .compat_ioctl = atalk_compat_ioctl,
1846 #endif
1847 .listen = sock_no_listen,
1848 .shutdown = sock_no_shutdown,
1849 .setsockopt = sock_no_setsockopt,
1850 .getsockopt = sock_no_getsockopt,
1851 .sendmsg = atalk_sendmsg,
1852 .recvmsg = atalk_recvmsg,
1853 .mmap = sock_no_mmap,
1854 .sendpage = sock_no_sendpage,
1855 };
1856
1857 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1858
1859 static struct notifier_block ddp_notifier = {
1860 .notifier_call = ddp_device_event,
1861 };
1862
1863 static struct packet_type ltalk_packet_type = {
1864 .type = __constant_htons(ETH_P_LOCALTALK),
1865 .func = ltalk_rcv,
1866 };
1867
1868 static struct packet_type ppptalk_packet_type = {
1869 .type = __constant_htons(ETH_P_PPPTALK),
1870 .func = atalk_rcv,
1871 };
1872
1873 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1874
1875 /* Export symbols for use by drivers when AppleTalk is a module */
1876 EXPORT_SYMBOL(aarp_send_ddp);
1877 EXPORT_SYMBOL(atrtr_get_dev);
1878 EXPORT_SYMBOL(atalk_find_dev_addr);
1879
1880 static char atalk_err_snap[] __initdata =
1881 KERN_CRIT "Unable to register DDP with SNAP.\n";
1882
1883 /* Called by proto.c on kernel start up */
atalk_init(void)1884 static int __init atalk_init(void)
1885 {
1886 int rc = proto_register(&ddp_proto, 0);
1887
1888 if (rc != 0)
1889 goto out;
1890
1891 (void)sock_register(&atalk_family_ops);
1892 ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1893 if (!ddp_dl)
1894 printk(atalk_err_snap);
1895
1896 dev_add_pack(<alk_packet_type);
1897 dev_add_pack(&ppptalk_packet_type);
1898
1899 register_netdevice_notifier(&ddp_notifier);
1900 aarp_proto_init();
1901 atalk_proc_init();
1902 atalk_register_sysctl();
1903 out:
1904 return rc;
1905 }
1906 module_init(atalk_init);
1907
1908 /*
1909 * No explicit module reference count manipulation is needed in the
1910 * protocol. Socket layer sets module reference count for us
1911 * and interfaces reference counting is done
1912 * by the network device layer.
1913 *
1914 * Ergo, before the AppleTalk module can be removed, all AppleTalk
1915 * sockets be closed from user space.
1916 */
atalk_exit(void)1917 static void __exit atalk_exit(void)
1918 {
1919 #ifdef CONFIG_SYSCTL
1920 atalk_unregister_sysctl();
1921 #endif /* CONFIG_SYSCTL */
1922 atalk_proc_exit();
1923 aarp_cleanup_module(); /* General aarp clean-up. */
1924 unregister_netdevice_notifier(&ddp_notifier);
1925 dev_remove_pack(<alk_packet_type);
1926 dev_remove_pack(&ppptalk_packet_type);
1927 unregister_snap_client(ddp_dl);
1928 sock_unregister(PF_APPLETALK);
1929 proto_unregister(&ddp_proto);
1930 }
1931 module_exit(atalk_exit);
1932
1933 MODULE_LICENSE("GPL");
1934 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1935 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1936 MODULE_ALIAS_NETPROTO(PF_APPLETALK);
1937