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 <linux/highmem.h>
67
68struct datalink_proto *ddp_dl, *aarp_dl;
69static const struct proto_ops atalk_dgram_ops;
70
71/**************************************************************************\
72*                                                                          *
73* Handlers for the socket list.                                            *
74*                                                                          *
75\**************************************************************************/
76
77HLIST_HEAD(atalk_sockets);
78DEFINE_RWLOCK(atalk_sockets_lock);
79
80static inline void __atalk_insert_socket(struct sock *sk)
81{
82	sk_add_node(sk, &atalk_sockets);
83}
84
85static 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
92static struct sock *atalk_search_socket(struct sockaddr_at *to,
93					struct atalk_iface *atif)
94{
95	struct sock *s;
96
97	read_lock_bh(&atalk_sockets_lock);
98	sk_for_each(s, &atalk_sockets) {
99		struct atalk_sock *at = at_sk(s);
100
101		if (to->sat_port != at->src_port)
102			continue;
103
104		if (to->sat_addr.s_net == ATADDR_ANYNET &&
105		    to->sat_addr.s_node == ATADDR_BCAST)
106			goto found;
107
108		if (to->sat_addr.s_net == at->src_net &&
109		    (to->sat_addr.s_node == at->src_node ||
110		     to->sat_addr.s_node == ATADDR_BCAST ||
111		     to->sat_addr.s_node == ATADDR_ANYNODE))
112			goto found;
113
114		/* XXXX.0 -- we got a request for this router. make sure
115		 * that the node is appropriately set. */
116		if (to->sat_addr.s_node == ATADDR_ANYNODE &&
117		    to->sat_addr.s_net != ATADDR_ANYNET &&
118		    atif->address.s_node == at->src_node) {
119			to->sat_addr.s_node = atif->address.s_node;
120			goto found;
121		}
122	}
123	s = NULL;
124found:
125	read_unlock_bh(&atalk_sockets_lock);
126	return s;
127}
128
129/**
130 * atalk_find_or_insert_socket - Try to find a socket matching ADDR
131 * @sk: socket to insert in the list if it is not there already
132 * @sat: address to search for
133 *
134 * Try to find a socket matching ADDR in the socket list, if found then return
135 * it. If not, insert SK into the socket list.
136 *
137 * This entire operation must execute atomically.
138 */
139static struct sock *atalk_find_or_insert_socket(struct sock *sk,
140						struct sockaddr_at *sat)
141{
142	struct sock *s;
143	struct atalk_sock *at;
144
145	write_lock_bh(&atalk_sockets_lock);
146	sk_for_each(s, &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. */
156found:
157	write_unlock_bh(&atalk_sockets_lock);
158	return s;
159}
160
161static void atalk_destroy_timer(unsigned long data)
162{
163	struct sock *sk = (struct sock *)data;
164
165	if (sk_has_allocations(sk)) {
166		sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
167		add_timer(&sk->sk_timer);
168	} else
169		sock_put(sk);
170}
171
172static inline void atalk_destroy_socket(struct sock *sk)
173{
174	atalk_remove_socket(sk);
175	skb_queue_purge(&sk->sk_receive_queue);
176
177	if (sk_has_allocations(sk)) {
178		setup_timer(&sk->sk_timer, atalk_destroy_timer,
179				(unsigned long)sk);
180		sk->sk_timer.expires	= jiffies + SOCK_DESTROY_TIME;
181		add_timer(&sk->sk_timer);
182	} else
183		sock_put(sk);
184}
185
186/**************************************************************************\
187*                                                                          *
188* Routing tables for the AppleTalk socket layer.                           *
189*                                                                          *
190\**************************************************************************/
191
192/* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
193struct atalk_route *atalk_routes;
194DEFINE_RWLOCK(atalk_routes_lock);
195
196struct atalk_iface *atalk_interfaces;
197DEFINE_RWLOCK(atalk_interfaces_lock);
198
199/* For probing devices or in a routerless network */
200struct atalk_route atrtr_default;
201
202/* AppleTalk interface control */
203/*
204 * Drop a device. Doesn't drop any of its routes - that is the caller's
205 * problem. Called when we down the interface or delete the address.
206 */
207static void atif_drop_device(struct net_device *dev)
208{
209	struct atalk_iface **iface = &atalk_interfaces;
210	struct atalk_iface *tmp;
211
212	write_lock_bh(&atalk_interfaces_lock);
213	while ((tmp = *iface) != NULL) {
214		if (tmp->dev == dev) {
215			*iface = tmp->next;
216			dev_put(dev);
217			kfree(tmp);
218			dev->atalk_ptr = NULL;
219		} else
220			iface = &tmp->next;
221	}
222	write_unlock_bh(&atalk_interfaces_lock);
223}
224
225static struct atalk_iface *atif_add_device(struct net_device *dev,
226					   struct atalk_addr *sa)
227{
228	struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
229
230	if (!iface)
231		goto out;
232
233	dev_hold(dev);
234	iface->dev = dev;
235	dev->atalk_ptr = iface;
236	iface->address = *sa;
237	iface->status = 0;
238
239	write_lock_bh(&atalk_interfaces_lock);
240	iface->next = atalk_interfaces;
241	atalk_interfaces = iface;
242	write_unlock_bh(&atalk_interfaces_lock);
243out:
244	return iface;
245}
246
247/* Perform phase 2 AARP probing on our tentative address */
248static int atif_probe_device(struct atalk_iface *atif)
249{
250	int netrange = ntohs(atif->nets.nr_lastnet) -
251			ntohs(atif->nets.nr_firstnet) + 1;
252	int probe_net = ntohs(atif->address.s_net);
253	int probe_node = atif->address.s_node;
254	int netct, nodect;
255
256	/* Offset the network we start probing with */
257	if (probe_net == ATADDR_ANYNET) {
258		probe_net = ntohs(atif->nets.nr_firstnet);
259		if (netrange)
260			probe_net += jiffies % netrange;
261	}
262	if (probe_node == ATADDR_ANYNODE)
263		probe_node = jiffies & 0xFF;
264
265	/* Scan the networks */
266	atif->status |= ATIF_PROBE;
267	for (netct = 0; netct <= netrange; netct++) {
268		/* Sweep the available nodes from a given start */
269		atif->address.s_net = htons(probe_net);
270		for (nodect = 0; nodect < 256; nodect++) {
271			atif->address.s_node = (nodect + probe_node) & 0xFF;
272			if (atif->address.s_node > 0 &&
273			    atif->address.s_node < 254) {
274				/* Probe a proposed address */
275				aarp_probe_network(atif);
276
277				if (!(atif->status & ATIF_PROBE_FAIL)) {
278					atif->status &= ~ATIF_PROBE;
279					return 0;
280				}
281			}
282			atif->status &= ~ATIF_PROBE_FAIL;
283		}
284		probe_net++;
285		if (probe_net > ntohs(atif->nets.nr_lastnet))
286			probe_net = ntohs(atif->nets.nr_firstnet);
287	}
288	atif->status &= ~ATIF_PROBE;
289
290	return -EADDRINUSE;	/* Network is full... */
291}
292
293
294/* Perform AARP probing for a proxy address */
295static int atif_proxy_probe_device(struct atalk_iface *atif,
296				   struct atalk_addr *proxy_addr)
297{
298	int netrange = ntohs(atif->nets.nr_lastnet) -
299			ntohs(atif->nets.nr_firstnet) + 1;
300	/* we probe the interface's network */
301	int probe_net = ntohs(atif->address.s_net);
302	int probe_node = ATADDR_ANYNODE;	    /* we'll take anything */
303	int netct, nodect;
304
305	/* Offset the network we start probing with */
306	if (probe_net == ATADDR_ANYNET) {
307		probe_net = ntohs(atif->nets.nr_firstnet);
308		if (netrange)
309			probe_net += jiffies % netrange;
310	}
311
312	if (probe_node == ATADDR_ANYNODE)
313		probe_node = jiffies & 0xFF;
314
315	/* Scan the networks */
316	for (netct = 0; netct <= netrange; netct++) {
317		/* Sweep the available nodes from a given start */
318		proxy_addr->s_net = htons(probe_net);
319		for (nodect = 0; nodect < 256; nodect++) {
320			proxy_addr->s_node = (nodect + probe_node) & 0xFF;
321			if (proxy_addr->s_node > 0 &&
322			    proxy_addr->s_node < 254) {
323				/* Tell AARP to probe a proposed address */
324				int ret = aarp_proxy_probe_network(atif,
325								    proxy_addr);
326
327				if (ret != -EADDRINUSE)
328					return ret;
329			}
330		}
331		probe_net++;
332		if (probe_net > ntohs(atif->nets.nr_lastnet))
333			probe_net = ntohs(atif->nets.nr_firstnet);
334	}
335
336	return -EADDRINUSE;	/* Network is full... */
337}
338
339
340struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
341{
342	struct atalk_iface *iface = dev->atalk_ptr;
343	return iface ? &iface->address : NULL;
344}
345
346static struct atalk_addr *atalk_find_primary(void)
347{
348	struct atalk_iface *fiface = NULL;
349	struct atalk_addr *retval;
350	struct atalk_iface *iface;
351
352	/*
353	 * Return a point-to-point interface only if
354	 * there is no non-ptp interface available.
355	 */
356	read_lock_bh(&atalk_interfaces_lock);
357	for (iface = atalk_interfaces; iface; iface = iface->next) {
358		if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
359			fiface = iface;
360		if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
361			retval = &iface->address;
362			goto out;
363		}
364	}
365
366	if (fiface)
367		retval = &fiface->address;
368	else if (atalk_interfaces)
369		retval = &atalk_interfaces->address;
370	else
371		retval = NULL;
372out:
373	read_unlock_bh(&atalk_interfaces_lock);
374	return retval;
375}
376
377/*
378 * Find a match for 'any network' - ie any of our interfaces with that
379 * node number will do just nicely.
380 */
381static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
382{
383	struct atalk_iface *iface = dev->atalk_ptr;
384
385	if (!iface || iface->status & ATIF_PROBE)
386		goto out_err;
387
388	if (node != ATADDR_BCAST &&
389	    iface->address.s_node != node &&
390	    node != ATADDR_ANYNODE)
391		goto out_err;
392out:
393	return iface;
394out_err:
395	iface = NULL;
396	goto out;
397}
398
399/* Find a match for a specific network:node pair */
400static struct atalk_iface *atalk_find_interface(__be16 net, int node)
401{
402	struct atalk_iface *iface;
403
404	read_lock_bh(&atalk_interfaces_lock);
405	for (iface = atalk_interfaces; iface; iface = iface->next) {
406		if ((node == ATADDR_BCAST ||
407		     node == ATADDR_ANYNODE ||
408		     iface->address.s_node == node) &&
409		    iface->address.s_net == net &&
410		    !(iface->status & ATIF_PROBE))
411			break;
412
413		/* XXXX.0 -- net.0 returns the iface associated with net */
414		if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
415		    ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
416		    ntohs(net) <= ntohs(iface->nets.nr_lastnet))
417			break;
418	}
419	read_unlock_bh(&atalk_interfaces_lock);
420	return iface;
421}
422
423
424/*
425 * Find a route for an AppleTalk packet. This ought to get cached in
426 * the socket (later on...). We know about host routes and the fact
427 * that a route must be direct to broadcast.
428 */
429static struct atalk_route *atrtr_find(struct atalk_addr *target)
430{
431	/*
432	 * we must search through all routes unless we find a
433	 * host route, because some host routes might overlap
434	 * network routes
435	 */
436	struct atalk_route *net_route = NULL;
437	struct atalk_route *r;
438
439	read_lock_bh(&atalk_routes_lock);
440	for (r = atalk_routes; r; r = r->next) {
441		if (!(r->flags & RTF_UP))
442			continue;
443
444		if (r->target.s_net == target->s_net) {
445			if (r->flags & RTF_HOST) {
446				/*
447				 * if this host route is for the target,
448				 * the we're done
449				 */
450				if (r->target.s_node == target->s_node)
451					goto out;
452			} else
453				/*
454				 * this route will work if there isn't a
455				 * direct host route, so cache it
456				 */
457				net_route = r;
458		}
459	}
460
461	/*
462	 * if we found a network route but not a direct host
463	 * route, then return it
464	 */
465	if (net_route)
466		r = net_route;
467	else if (atrtr_default.dev)
468		r = &atrtr_default;
469	else /* No route can be found */
470		r = NULL;
471out:
472	read_unlock_bh(&atalk_routes_lock);
473	return r;
474}
475
476
477/*
478 * Given an AppleTalk network, find the device to use. This can be
479 * a simple lookup.
480 */
481struct net_device *atrtr_get_dev(struct atalk_addr *sa)
482{
483	struct atalk_route *atr = atrtr_find(sa);
484	return atr ? atr->dev : NULL;
485}
486
487/* Set up a default router */
488static void atrtr_set_default(struct net_device *dev)
489{
490	atrtr_default.dev	     = dev;
491	atrtr_default.flags	     = RTF_UP;
492	atrtr_default.gateway.s_net  = htons(0);
493	atrtr_default.gateway.s_node = 0;
494}
495
496/*
497 * Add a router. Basically make sure it looks valid and stuff the
498 * entry in the list. While it uses netranges we always set them to one
499 * entry to work like netatalk.
500 */
501static int atrtr_create(struct rtentry *r, struct net_device *devhint)
502{
503	struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
504	struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
505	struct atalk_route *rt;
506	struct atalk_iface *iface, *riface;
507	int retval = -EINVAL;
508
509	/*
510	 * Fixme: Raise/Lower a routing change semaphore for these
511	 * operations.
512	 */
513
514	/* Validate the request */
515	if (ta->sat_family != AF_APPLETALK ||
516	    (!devhint && ga->sat_family != AF_APPLETALK))
517		goto out;
518
519	/* Now walk the routing table and make our decisions */
520	write_lock_bh(&atalk_routes_lock);
521	for (rt = atalk_routes; rt; rt = rt->next) {
522		if (r->rt_flags != rt->flags)
523			continue;
524
525		if (ta->sat_addr.s_net == rt->target.s_net) {
526			if (!(rt->flags & RTF_HOST))
527				break;
528			if (ta->sat_addr.s_node == rt->target.s_node)
529				break;
530		}
531	}
532
533	if (!devhint) {
534		riface = NULL;
535
536		read_lock_bh(&atalk_interfaces_lock);
537		for (iface = atalk_interfaces; iface; iface = iface->next) {
538			if (!riface &&
539			    ntohs(ga->sat_addr.s_net) >=
540					ntohs(iface->nets.nr_firstnet) &&
541			    ntohs(ga->sat_addr.s_net) <=
542					ntohs(iface->nets.nr_lastnet))
543				riface = iface;
544
545			if (ga->sat_addr.s_net == iface->address.s_net &&
546			    ga->sat_addr.s_node == iface->address.s_node)
547				riface = iface;
548		}
549		read_unlock_bh(&atalk_interfaces_lock);
550
551		retval = -ENETUNREACH;
552		if (!riface)
553			goto out_unlock;
554
555		devhint = riface->dev;
556	}
557
558	if (!rt) {
559		rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
560
561		retval = -ENOBUFS;
562		if (!rt)
563			goto out_unlock;
564
565		rt->next = atalk_routes;
566		atalk_routes = rt;
567	}
568
569	/* Fill in the routing entry */
570	rt->target  = ta->sat_addr;
571	dev_hold(devhint);
572	rt->dev     = devhint;
573	rt->flags   = r->rt_flags;
574	rt->gateway = ga->sat_addr;
575
576	retval = 0;
577out_unlock:
578	write_unlock_bh(&atalk_routes_lock);
579out:
580	return retval;
581}
582
583/* Delete a route. Find it and discard it */
584static int atrtr_delete(struct atalk_addr *addr)
585{
586	struct atalk_route **r = &atalk_routes;
587	int retval = 0;
588	struct atalk_route *tmp;
589
590	write_lock_bh(&atalk_routes_lock);
591	while ((tmp = *r) != NULL) {
592		if (tmp->target.s_net == addr->s_net &&
593		    (!(tmp->flags&RTF_GATEWAY) ||
594		     tmp->target.s_node == addr->s_node)) {
595			*r = tmp->next;
596			dev_put(tmp->dev);
597			kfree(tmp);
598			goto out;
599		}
600		r = &tmp->next;
601	}
602	retval = -ENOENT;
603out:
604	write_unlock_bh(&atalk_routes_lock);
605	return retval;
606}
607
608/*
609 * Called when a device is downed. Just throw away any routes
610 * via it.
611 */
612static void atrtr_device_down(struct net_device *dev)
613{
614	struct atalk_route **r = &atalk_routes;
615	struct atalk_route *tmp;
616
617	write_lock_bh(&atalk_routes_lock);
618	while ((tmp = *r) != NULL) {
619		if (tmp->dev == dev) {
620			*r = tmp->next;
621			dev_put(dev);
622			kfree(tmp);
623		} else
624			r = &tmp->next;
625	}
626	write_unlock_bh(&atalk_routes_lock);
627
628	if (atrtr_default.dev == dev)
629		atrtr_set_default(NULL);
630}
631
632/* Actually down the interface */
633static inline void atalk_dev_down(struct net_device *dev)
634{
635	atrtr_device_down(dev);	/* Remove all routes for the device */
636	aarp_device_down(dev);	/* Remove AARP entries for the device */
637	atif_drop_device(dev);	/* Remove the device */
638}
639
640/*
641 * A device event has occurred. Watch for devices going down and
642 * delete our use of them (iface and route).
643 */
644static int ddp_device_event(struct notifier_block *this, unsigned long event,
645			    void *ptr)
646{
647	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
648
649	if (!net_eq(dev_net(dev), &init_net))
650		return NOTIFY_DONE;
651
652	if (event == NETDEV_DOWN)
653		/* Discard any use of this */
654		atalk_dev_down(dev);
655
656	return NOTIFY_DONE;
657}
658
659/* ioctl calls. Shouldn't even need touching */
660/* Device configuration ioctl calls */
661static int atif_ioctl(int cmd, void __user *arg)
662{
663	static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
664	struct ifreq atreq;
665	struct atalk_netrange *nr;
666	struct sockaddr_at *sa;
667	struct net_device *dev;
668	struct atalk_iface *atif;
669	int ct;
670	int limit;
671	struct rtentry rtdef;
672	int add_route;
673
674	if (copy_from_user(&atreq, arg, sizeof(atreq)))
675		return -EFAULT;
676
677	dev = __dev_get_by_name(&init_net, atreq.ifr_name);
678	if (!dev)
679		return -ENODEV;
680
681	sa = (struct sockaddr_at *)&atreq.ifr_addr;
682	atif = atalk_find_dev(dev);
683
684	switch (cmd) {
685	case SIOCSIFADDR:
686		if (!capable(CAP_NET_ADMIN))
687			return -EPERM;
688		if (sa->sat_family != AF_APPLETALK)
689			return -EINVAL;
690		if (dev->type != ARPHRD_ETHER &&
691		    dev->type != ARPHRD_LOOPBACK &&
692		    dev->type != ARPHRD_LOCALTLK &&
693		    dev->type != ARPHRD_PPP)
694			return -EPROTONOSUPPORT;
695
696		nr = (struct atalk_netrange *)&sa->sat_zero[0];
697		add_route = 1;
698
699		/*
700		 * if this is a point-to-point iface, and we already
701		 * have an iface for this AppleTalk address, then we
702		 * should not add a route
703		 */
704		if ((dev->flags & IFF_POINTOPOINT) &&
705		    atalk_find_interface(sa->sat_addr.s_net,
706					 sa->sat_addr.s_node)) {
707			printk(KERN_DEBUG "AppleTalk: point-to-point "
708			       "interface added with "
709			       "existing address\n");
710			add_route = 0;
711		}
712
713		/*
714		 * Phase 1 is fine on LocalTalk but we don't do
715		 * EtherTalk phase 1. Anyone wanting to add it go ahead.
716		 */
717		if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
718			return -EPROTONOSUPPORT;
719		if (sa->sat_addr.s_node == ATADDR_BCAST ||
720		    sa->sat_addr.s_node == 254)
721			return -EINVAL;
722		if (atif) {
723			/* Already setting address */
724			if (atif->status & ATIF_PROBE)
725				return -EBUSY;
726
727			atif->address.s_net  = sa->sat_addr.s_net;
728			atif->address.s_node = sa->sat_addr.s_node;
729			atrtr_device_down(dev);	/* Flush old routes */
730		} else {
731			atif = atif_add_device(dev, &sa->sat_addr);
732			if (!atif)
733				return -ENOMEM;
734		}
735		atif->nets = *nr;
736
737		/*
738		 * Check if the chosen address is used. If so we
739		 * error and atalkd will try another.
740		 */
741
742		if (!(dev->flags & IFF_LOOPBACK) &&
743		    !(dev->flags & IFF_POINTOPOINT) &&
744		    atif_probe_device(atif) < 0) {
745			atif_drop_device(dev);
746			return -EADDRINUSE;
747		}
748
749		/* Hey it worked - add the direct routes */
750		sa = (struct sockaddr_at *)&rtdef.rt_gateway;
751		sa->sat_family = AF_APPLETALK;
752		sa->sat_addr.s_net  = atif->address.s_net;
753		sa->sat_addr.s_node = atif->address.s_node;
754		sa = (struct sockaddr_at *)&rtdef.rt_dst;
755		rtdef.rt_flags = RTF_UP;
756		sa->sat_family = AF_APPLETALK;
757		sa->sat_addr.s_node = ATADDR_ANYNODE;
758		if (dev->flags & IFF_LOOPBACK ||
759		    dev->flags & IFF_POINTOPOINT)
760			rtdef.rt_flags |= RTF_HOST;
761
762		/* Routerless initial state */
763		if (nr->nr_firstnet == htons(0) &&
764		    nr->nr_lastnet == htons(0xFFFE)) {
765			sa->sat_addr.s_net = atif->address.s_net;
766			atrtr_create(&rtdef, dev);
767			atrtr_set_default(dev);
768		} else {
769			limit = ntohs(nr->nr_lastnet);
770			if (limit - ntohs(nr->nr_firstnet) > 4096) {
771				printk(KERN_WARNING "Too many routes/"
772				       "iface.\n");
773				return -EINVAL;
774			}
775			if (add_route)
776				for (ct = ntohs(nr->nr_firstnet);
777				     ct <= limit; ct++) {
778					sa->sat_addr.s_net = htons(ct);
779					atrtr_create(&rtdef, dev);
780				}
781		}
782		dev_mc_add_global(dev, aarp_mcast);
783		return 0;
784
785	case SIOCGIFADDR:
786		if (!atif)
787			return -EADDRNOTAVAIL;
788
789		sa->sat_family = AF_APPLETALK;
790		sa->sat_addr = atif->address;
791		break;
792
793	case SIOCGIFBRDADDR:
794		if (!atif)
795			return -EADDRNOTAVAIL;
796
797		sa->sat_family = AF_APPLETALK;
798		sa->sat_addr.s_net = atif->address.s_net;
799		sa->sat_addr.s_node = ATADDR_BCAST;
800		break;
801
802	case SIOCATALKDIFADDR:
803	case SIOCDIFADDR:
804		if (!capable(CAP_NET_ADMIN))
805			return -EPERM;
806		if (sa->sat_family != AF_APPLETALK)
807			return -EINVAL;
808		atalk_dev_down(dev);
809		break;
810
811	case SIOCSARP:
812		if (!capable(CAP_NET_ADMIN))
813			return -EPERM;
814		if (sa->sat_family != AF_APPLETALK)
815			return -EINVAL;
816		/*
817		 * for now, we only support proxy AARP on ELAP;
818		 * we should be able to do it for LocalTalk, too.
819		 */
820		if (dev->type != ARPHRD_ETHER)
821			return -EPROTONOSUPPORT;
822
823		/*
824		 * atif points to the current interface on this network;
825		 * we aren't concerned about its current status (at
826		 * least for now), but it has all the settings about
827		 * the network we're going to probe. Consequently, it
828		 * must exist.
829		 */
830		if (!atif)
831			return -EADDRNOTAVAIL;
832
833		nr = (struct atalk_netrange *)&(atif->nets);
834		/*
835		 * Phase 1 is fine on Localtalk but we don't do
836		 * Ethertalk phase 1. Anyone wanting to add it go ahead.
837		 */
838		if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
839			return -EPROTONOSUPPORT;
840
841		if (sa->sat_addr.s_node == ATADDR_BCAST ||
842		    sa->sat_addr.s_node == 254)
843			return -EINVAL;
844
845		/*
846		 * Check if the chosen address is used. If so we
847		 * error and ATCP will try another.
848		 */
849		if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
850			return -EADDRINUSE;
851
852		/*
853		 * We now have an address on the local network, and
854		 * the AARP code will defend it for us until we take it
855		 * down. We don't set up any routes right now, because
856		 * ATCP will install them manually via SIOCADDRT.
857		 */
858		break;
859
860	case SIOCDARP:
861		if (!capable(CAP_NET_ADMIN))
862			return -EPERM;
863		if (sa->sat_family != AF_APPLETALK)
864			return -EINVAL;
865		if (!atif)
866			return -EADDRNOTAVAIL;
867
868		/* give to aarp module to remove proxy entry */
869		aarp_proxy_remove(atif->dev, &(sa->sat_addr));
870		return 0;
871	}
872
873	return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
874}
875
876/* Routing ioctl() calls */
877static int atrtr_ioctl(unsigned int cmd, void __user *arg)
878{
879	struct rtentry rt;
880
881	if (copy_from_user(&rt, arg, sizeof(rt)))
882		return -EFAULT;
883
884	switch (cmd) {
885	case SIOCDELRT:
886		if (rt.rt_dst.sa_family != AF_APPLETALK)
887			return -EINVAL;
888		return atrtr_delete(&((struct sockaddr_at *)
889				      &rt.rt_dst)->sat_addr);
890
891	case SIOCADDRT: {
892		struct net_device *dev = NULL;
893		if (rt.rt_dev) {
894			char name[IFNAMSIZ];
895			if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
896				return -EFAULT;
897			name[IFNAMSIZ-1] = '\0';
898			dev = __dev_get_by_name(&init_net, name);
899			if (!dev)
900				return -ENODEV;
901		}
902		return atrtr_create(&rt, dev);
903	}
904	}
905	return -EINVAL;
906}
907
908/**************************************************************************\
909*                                                                          *
910* Handling for system calls applied via the various interfaces to an       *
911* AppleTalk socket object.                                                 *
912*                                                                          *
913\**************************************************************************/
914
915/*
916 * Checksum: This is 'optional'. It's quite likely also a good
917 * candidate for assembler hackery 8)
918 */
919static unsigned long atalk_sum_partial(const unsigned char *data,
920				       int len, unsigned long sum)
921{
922	/* This ought to be unwrapped neatly. I'll trust gcc for now */
923	while (len--) {
924		sum += *data++;
925		sum = rol16(sum, 1);
926	}
927	return sum;
928}
929
930/*  Checksum skb data --  similar to skb_checksum  */
931static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
932				   int len, unsigned long sum)
933{
934	int start = skb_headlen(skb);
935	struct sk_buff *frag_iter;
936	int i, copy;
937
938	/* checksum stuff in header space */
939	if ((copy = start - offset) > 0) {
940		if (copy > len)
941			copy = len;
942		sum = atalk_sum_partial(skb->data + offset, copy, sum);
943		if ((len -= copy) == 0)
944			return sum;
945
946		offset += copy;
947	}
948
949	/* checksum stuff in frags */
950	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
951		int end;
952		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
953		WARN_ON(start > offset + len);
954
955		end = start + skb_frag_size(frag);
956		if ((copy = end - offset) > 0) {
957			u8 *vaddr;
958
959			if (copy > len)
960				copy = len;
961			vaddr = kmap_atomic(skb_frag_page(frag));
962			sum = atalk_sum_partial(vaddr + frag->page_offset +
963						  offset - start, copy, sum);
964			kunmap_atomic(vaddr);
965
966			if (!(len -= copy))
967				return sum;
968			offset += copy;
969		}
970		start = end;
971	}
972
973	skb_walk_frags(skb, frag_iter) {
974		int end;
975
976		WARN_ON(start > offset + len);
977
978		end = start + frag_iter->len;
979		if ((copy = end - offset) > 0) {
980			if (copy > len)
981				copy = len;
982			sum = atalk_sum_skb(frag_iter, offset - start,
983					    copy, sum);
984			if ((len -= copy) == 0)
985				return sum;
986			offset += copy;
987		}
988		start = end;
989	}
990
991	BUG_ON(len > 0);
992
993	return sum;
994}
995
996static __be16 atalk_checksum(const struct sk_buff *skb, int len)
997{
998	unsigned long sum;
999
1000	/* skip header 4 bytes */
1001	sum = atalk_sum_skb(skb, 4, len-4, 0);
1002
1003	/* Use 0xFFFF for 0. 0 itself means none */
1004	return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1005}
1006
1007static struct proto ddp_proto = {
1008	.name	  = "DDP",
1009	.owner	  = THIS_MODULE,
1010	.obj_size = sizeof(struct atalk_sock),
1011};
1012
1013/*
1014 * Create a socket. Initialise the socket, blank the addresses
1015 * set the state.
1016 */
1017static int atalk_create(struct net *net, struct socket *sock, int protocol,
1018			int kern)
1019{
1020	struct sock *sk;
1021	int rc = -ESOCKTNOSUPPORT;
1022
1023	if (!net_eq(net, &init_net))
1024		return -EAFNOSUPPORT;
1025
1026	/*
1027	 * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1028	 * and gives you the full ELAP frame. Should be handy for CAP 8)
1029	 */
1030	if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1031		goto out;
1032	rc = -ENOMEM;
1033	sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto);
1034	if (!sk)
1035		goto out;
1036	rc = 0;
1037	sock->ops = &atalk_dgram_ops;
1038	sock_init_data(sock, sk);
1039
1040	/* Checksums on by default */
1041	sock_set_flag(sk, SOCK_ZAPPED);
1042out:
1043	return rc;
1044}
1045
1046/* Free a socket. No work needed */
1047static int atalk_release(struct socket *sock)
1048{
1049	struct sock *sk = sock->sk;
1050
1051	if (sk) {
1052		sock_hold(sk);
1053		lock_sock(sk);
1054
1055		sock_orphan(sk);
1056		sock->sk = NULL;
1057		atalk_destroy_socket(sk);
1058
1059		release_sock(sk);
1060		sock_put(sk);
1061	}
1062	return 0;
1063}
1064
1065/**
1066 * atalk_pick_and_bind_port - Pick a source port when one is not given
1067 * @sk: socket to insert into the tables
1068 * @sat: address to search for
1069 *
1070 * Pick a source port when one is not given. If we can find a suitable free
1071 * one, we insert the socket into the tables using it.
1072 *
1073 * This whole operation must be atomic.
1074 */
1075static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1076{
1077	int retval;
1078
1079	write_lock_bh(&atalk_sockets_lock);
1080
1081	for (sat->sat_port = ATPORT_RESERVED;
1082	     sat->sat_port < ATPORT_LAST;
1083	     sat->sat_port++) {
1084		struct sock *s;
1085
1086		sk_for_each(s, &atalk_sockets) {
1087			struct atalk_sock *at = at_sk(s);
1088
1089			if (at->src_net == sat->sat_addr.s_net &&
1090			    at->src_node == sat->sat_addr.s_node &&
1091			    at->src_port == sat->sat_port)
1092				goto try_next_port;
1093		}
1094
1095		/* Wheee, it's free, assign and insert. */
1096		__atalk_insert_socket(sk);
1097		at_sk(sk)->src_port = sat->sat_port;
1098		retval = 0;
1099		goto out;
1100
1101try_next_port:;
1102	}
1103
1104	retval = -EBUSY;
1105out:
1106	write_unlock_bh(&atalk_sockets_lock);
1107	return retval;
1108}
1109
1110static int atalk_autobind(struct sock *sk)
1111{
1112	struct atalk_sock *at = at_sk(sk);
1113	struct sockaddr_at sat;
1114	struct atalk_addr *ap = atalk_find_primary();
1115	int n = -EADDRNOTAVAIL;
1116
1117	if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1118		goto out;
1119
1120	at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1121	at->src_node = sat.sat_addr.s_node = ap->s_node;
1122
1123	n = atalk_pick_and_bind_port(sk, &sat);
1124	if (!n)
1125		sock_reset_flag(sk, SOCK_ZAPPED);
1126out:
1127	return n;
1128}
1129
1130/* Set the address 'our end' of the connection */
1131static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1132{
1133	struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1134	struct sock *sk = sock->sk;
1135	struct atalk_sock *at = at_sk(sk);
1136	int err;
1137
1138	if (!sock_flag(sk, SOCK_ZAPPED) ||
1139	    addr_len != sizeof(struct sockaddr_at))
1140		return -EINVAL;
1141
1142	if (addr->sat_family != AF_APPLETALK)
1143		return -EAFNOSUPPORT;
1144
1145	lock_sock(sk);
1146	if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1147		struct atalk_addr *ap = atalk_find_primary();
1148
1149		err = -EADDRNOTAVAIL;
1150		if (!ap)
1151			goto out;
1152
1153		at->src_net  = addr->sat_addr.s_net = ap->s_net;
1154		at->src_node = addr->sat_addr.s_node = ap->s_node;
1155	} else {
1156		err = -EADDRNOTAVAIL;
1157		if (!atalk_find_interface(addr->sat_addr.s_net,
1158					  addr->sat_addr.s_node))
1159			goto out;
1160
1161		at->src_net  = addr->sat_addr.s_net;
1162		at->src_node = addr->sat_addr.s_node;
1163	}
1164
1165	if (addr->sat_port == ATADDR_ANYPORT) {
1166		err = atalk_pick_and_bind_port(sk, addr);
1167
1168		if (err < 0)
1169			goto out;
1170	} else {
1171		at->src_port = addr->sat_port;
1172
1173		err = -EADDRINUSE;
1174		if (atalk_find_or_insert_socket(sk, addr))
1175			goto out;
1176	}
1177
1178	sock_reset_flag(sk, SOCK_ZAPPED);
1179	err = 0;
1180out:
1181	release_sock(sk);
1182	return err;
1183}
1184
1185/* Set the address we talk to */
1186static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1187			 int addr_len, int flags)
1188{
1189	struct sock *sk = sock->sk;
1190	struct atalk_sock *at = at_sk(sk);
1191	struct sockaddr_at *addr;
1192	int err;
1193
1194	sk->sk_state   = TCP_CLOSE;
1195	sock->state = SS_UNCONNECTED;
1196
1197	if (addr_len != sizeof(*addr))
1198		return -EINVAL;
1199
1200	addr = (struct sockaddr_at *)uaddr;
1201
1202	if (addr->sat_family != AF_APPLETALK)
1203		return -EAFNOSUPPORT;
1204
1205	if (addr->sat_addr.s_node == ATADDR_BCAST &&
1206	    !sock_flag(sk, SOCK_BROADCAST)) {
1207#if 1
1208		pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
1209			current->comm);
1210#else
1211		return -EACCES;
1212#endif
1213	}
1214
1215	lock_sock(sk);
1216	err = -EBUSY;
1217	if (sock_flag(sk, SOCK_ZAPPED))
1218		if (atalk_autobind(sk) < 0)
1219			goto out;
1220
1221	err = -ENETUNREACH;
1222	if (!atrtr_get_dev(&addr->sat_addr))
1223		goto out;
1224
1225	at->dest_port = addr->sat_port;
1226	at->dest_net  = addr->sat_addr.s_net;
1227	at->dest_node = addr->sat_addr.s_node;
1228
1229	sock->state  = SS_CONNECTED;
1230	sk->sk_state = TCP_ESTABLISHED;
1231	err = 0;
1232out:
1233	release_sock(sk);
1234	return err;
1235}
1236
1237/*
1238 * Find the name of an AppleTalk socket. Just copy the right
1239 * fields into the sockaddr.
1240 */
1241static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1242			 int *uaddr_len, int peer)
1243{
1244	struct sockaddr_at sat;
1245	struct sock *sk = sock->sk;
1246	struct atalk_sock *at = at_sk(sk);
1247	int err;
1248
1249	lock_sock(sk);
1250	err = -ENOBUFS;
1251	if (sock_flag(sk, SOCK_ZAPPED))
1252		if (atalk_autobind(sk) < 0)
1253			goto out;
1254
1255	*uaddr_len = sizeof(struct sockaddr_at);
1256	memset(&sat, 0, sizeof(sat));
1257
1258	if (peer) {
1259		err = -ENOTCONN;
1260		if (sk->sk_state != TCP_ESTABLISHED)
1261			goto out;
1262
1263		sat.sat_addr.s_net  = at->dest_net;
1264		sat.sat_addr.s_node = at->dest_node;
1265		sat.sat_port	    = at->dest_port;
1266	} else {
1267		sat.sat_addr.s_net  = at->src_net;
1268		sat.sat_addr.s_node = at->src_node;
1269		sat.sat_port	    = at->src_port;
1270	}
1271
1272	err = 0;
1273	sat.sat_family = AF_APPLETALK;
1274	memcpy(uaddr, &sat, sizeof(sat));
1275
1276out:
1277	release_sock(sk);
1278	return err;
1279}
1280
1281#if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1282static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1283{
1284	return skb->data[12] == 22;
1285}
1286
1287static int handle_ip_over_ddp(struct sk_buff *skb)
1288{
1289	struct net_device *dev = __dev_get_by_name(&init_net, "ipddp0");
1290	struct net_device_stats *stats;
1291
1292	/* This needs to be able to handle ipddp"N" devices */
1293	if (!dev) {
1294		kfree_skb(skb);
1295		return NET_RX_DROP;
1296	}
1297
1298	skb->protocol = htons(ETH_P_IP);
1299	skb_pull(skb, 13);
1300	skb->dev   = dev;
1301	skb_reset_transport_header(skb);
1302
1303	stats = netdev_priv(dev);
1304	stats->rx_packets++;
1305	stats->rx_bytes += skb->len + 13;
1306	return netif_rx(skb);  /* Send the SKB up to a higher place. */
1307}
1308#else
1309/* make it easy for gcc to optimize this test out, i.e. kill the code */
1310#define is_ip_over_ddp(skb) 0
1311#define handle_ip_over_ddp(skb) 0
1312#endif
1313
1314static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1315			      struct ddpehdr *ddp, __u16 len_hops, int origlen)
1316{
1317	struct atalk_route *rt;
1318	struct atalk_addr ta;
1319
1320	/*
1321	 * Don't route multicast, etc., packets, or packets sent to "this
1322	 * network"
1323	 */
1324	if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1325		/*
1326		 * FIXME:
1327		 *
1328		 * Can it ever happen that a packet is from a PPP iface and
1329		 * needs to be broadcast onto the default network?
1330		 */
1331		if (dev->type == ARPHRD_PPP)
1332			printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1333					  "packet received from PPP iface\n");
1334		goto free_it;
1335	}
1336
1337	ta.s_net  = ddp->deh_dnet;
1338	ta.s_node = ddp->deh_dnode;
1339
1340	/* Route the packet */
1341	rt = atrtr_find(&ta);
1342	/* increment hops count */
1343	len_hops += 1 << 10;
1344	if (!rt || !(len_hops & (15 << 10)))
1345		goto free_it;
1346
1347	/* FIXME: use skb->cb to be able to use shared skbs */
1348
1349	/*
1350	 * Route goes through another gateway, so set the target to the
1351	 * gateway instead.
1352	 */
1353
1354	if (rt->flags & RTF_GATEWAY) {
1355		ta.s_net  = rt->gateway.s_net;
1356		ta.s_node = rt->gateway.s_node;
1357	}
1358
1359	/* Fix up skb->len field */
1360	skb_trim(skb, min_t(unsigned int, origlen,
1361			    (rt->dev->hard_header_len +
1362			     ddp_dl->header_length + (len_hops & 1023))));
1363
1364	/* FIXME: use skb->cb to be able to use shared skbs */
1365	ddp->deh_len_hops = htons(len_hops);
1366
1367	/*
1368	 * Send the buffer onwards
1369	 *
1370	 * Now we must always be careful. If it's come from LocalTalk to
1371	 * EtherTalk it might not fit
1372	 *
1373	 * Order matters here: If a packet has to be copied to make a new
1374	 * headroom (rare hopefully) then it won't need unsharing.
1375	 *
1376	 * Note. ddp-> becomes invalid at the realloc.
1377	 */
1378	if (skb_headroom(skb) < 22) {
1379		/* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1380		struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1381		kfree_skb(skb);
1382		skb = nskb;
1383	} else
1384		skb = skb_unshare(skb, GFP_ATOMIC);
1385
1386	/*
1387	 * If the buffer didn't vanish into the lack of space bitbucket we can
1388	 * send it.
1389	 */
1390	if (skb == NULL)
1391		goto drop;
1392
1393	if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1394		return NET_RX_DROP;
1395	return NET_RX_SUCCESS;
1396free_it:
1397	kfree_skb(skb);
1398drop:
1399	return NET_RX_DROP;
1400}
1401
1402/**
1403 *	atalk_rcv - Receive a packet (in skb) from device dev
1404 *	@skb - packet received
1405 *	@dev - network device where the packet comes from
1406 *	@pt - packet type
1407 *
1408 *	Receive a packet (in skb) from device dev. This has come from the SNAP
1409 *	decoder, and on entry skb->transport_header is the DDP header, skb->len
1410 *	is the DDP header, skb->len is the DDP length. The physical headers
1411 *	have been extracted. PPP should probably pass frames marked as for this
1412 *	layer.  [ie ARPHRD_ETHERTALK]
1413 */
1414static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1415		     struct packet_type *pt, struct net_device *orig_dev)
1416{
1417	struct ddpehdr *ddp;
1418	struct sock *sock;
1419	struct atalk_iface *atif;
1420	struct sockaddr_at tosat;
1421	int origlen;
1422	__u16 len_hops;
1423
1424	if (!net_eq(dev_net(dev), &init_net))
1425		goto drop;
1426
1427	/* Don't mangle buffer if shared */
1428	if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1429		goto out;
1430
1431	/* Size check and make sure header is contiguous */
1432	if (!pskb_may_pull(skb, sizeof(*ddp)))
1433		goto drop;
1434
1435	ddp = ddp_hdr(skb);
1436
1437	len_hops = ntohs(ddp->deh_len_hops);
1438
1439	/* Trim buffer in case of stray trailing data */
1440	origlen = skb->len;
1441	skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1442
1443	/*
1444	 * Size check to see if ddp->deh_len was crap
1445	 * (Otherwise we'll detonate most spectacularly
1446	 * in the middle of atalk_checksum() or recvmsg()).
1447	 */
1448	if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1449		pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1450			 "skb->len=%u)\n", len_hops & 1023, skb->len);
1451		goto drop;
1452	}
1453
1454	/*
1455	 * Any checksums. Note we don't do htons() on this == is assumed to be
1456	 * valid for net byte orders all over the networking code...
1457	 */
1458	if (ddp->deh_sum &&
1459	    atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1460		/* Not a valid AppleTalk frame - dustbin time */
1461		goto drop;
1462
1463	/* Check the packet is aimed at us */
1464	if (!ddp->deh_dnet)	/* Net 0 is 'this network' */
1465		atif = atalk_find_anynet(ddp->deh_dnode, dev);
1466	else
1467		atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1468
1469	if (!atif) {
1470		/* Not ours, so we route the packet via the correct
1471		 * AppleTalk iface
1472		 */
1473		return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1474	}
1475
1476	/* if IP over DDP is not selected this code will be optimized out */
1477	if (is_ip_over_ddp(skb))
1478		return handle_ip_over_ddp(skb);
1479	/*
1480	 * Which socket - atalk_search_socket() looks for a *full match*
1481	 * of the <net, node, port> tuple.
1482	 */
1483	tosat.sat_addr.s_net  = ddp->deh_dnet;
1484	tosat.sat_addr.s_node = ddp->deh_dnode;
1485	tosat.sat_port	      = ddp->deh_dport;
1486
1487	sock = atalk_search_socket(&tosat, atif);
1488	if (!sock) /* But not one of our sockets */
1489		goto drop;
1490
1491	/* Queue packet (standard) */
1492	if (sock_queue_rcv_skb(sock, skb) < 0)
1493		goto drop;
1494
1495	return NET_RX_SUCCESS;
1496
1497drop:
1498	kfree_skb(skb);
1499out:
1500	return NET_RX_DROP;
1501
1502}
1503
1504/*
1505 * Receive a LocalTalk frame. We make some demands on the caller here.
1506 * Caller must provide enough headroom on the packet to pull the short
1507 * header and append a long one.
1508 */
1509static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1510		     struct packet_type *pt, struct net_device *orig_dev)
1511{
1512	if (!net_eq(dev_net(dev), &init_net))
1513		goto freeit;
1514
1515	/* Expand any short form frames */
1516	if (skb_mac_header(skb)[2] == 1) {
1517		struct ddpehdr *ddp;
1518		/* Find our address */
1519		struct atalk_addr *ap = atalk_find_dev_addr(dev);
1520
1521		if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1522			goto freeit;
1523
1524		/* Don't mangle buffer if shared */
1525		if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1526			return 0;
1527
1528		/*
1529		 * The push leaves us with a ddephdr not an shdr, and
1530		 * handily the port bytes in the right place preset.
1531		 */
1532		ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1533
1534		/* Now fill in the long header */
1535
1536		/*
1537		 * These two first. The mac overlays the new source/dest
1538		 * network information so we MUST copy these before
1539		 * we write the network numbers !
1540		 */
1541
1542		ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1543		ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1544
1545		ddp->deh_dnet  = ap->s_net;	/* Network number */
1546		ddp->deh_snet  = ap->s_net;
1547		ddp->deh_sum   = 0;		/* No checksum */
1548		/*
1549		 * Not sure about this bit...
1550		 */
1551		/* Non routable, so force a drop if we slip up later */
1552		ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1553	}
1554	skb_reset_transport_header(skb);
1555
1556	return atalk_rcv(skb, dev, pt, orig_dev);
1557freeit:
1558	kfree_skb(skb);
1559	return 0;
1560}
1561
1562static int atalk_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1563{
1564	struct sock *sk = sock->sk;
1565	struct atalk_sock *at = at_sk(sk);
1566	DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
1567	int flags = msg->msg_flags;
1568	int loopback = 0;
1569	struct sockaddr_at local_satalk, gsat;
1570	struct sk_buff *skb;
1571	struct net_device *dev;
1572	struct ddpehdr *ddp;
1573	int size;
1574	struct atalk_route *rt;
1575	int err;
1576
1577	if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1578		return -EINVAL;
1579
1580	if (len > DDP_MAXSZ)
1581		return -EMSGSIZE;
1582
1583	lock_sock(sk);
1584	if (usat) {
1585		err = -EBUSY;
1586		if (sock_flag(sk, SOCK_ZAPPED))
1587			if (atalk_autobind(sk) < 0)
1588				goto out;
1589
1590		err = -EINVAL;
1591		if (msg->msg_namelen < sizeof(*usat) ||
1592		    usat->sat_family != AF_APPLETALK)
1593			goto out;
1594
1595		err = -EPERM;
1596		/* netatalk didn't implement this check */
1597		if (usat->sat_addr.s_node == ATADDR_BCAST &&
1598		    !sock_flag(sk, SOCK_BROADCAST)) {
1599			goto out;
1600		}
1601	} else {
1602		err = -ENOTCONN;
1603		if (sk->sk_state != TCP_ESTABLISHED)
1604			goto out;
1605		usat = &local_satalk;
1606		usat->sat_family      = AF_APPLETALK;
1607		usat->sat_port	      = at->dest_port;
1608		usat->sat_addr.s_node = at->dest_node;
1609		usat->sat_addr.s_net  = at->dest_net;
1610	}
1611
1612	/* Build a packet */
1613	SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1614
1615	/* For headers */
1616	size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1617
1618	if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1619		rt = atrtr_find(&usat->sat_addr);
1620	} else {
1621		struct atalk_addr at_hint;
1622
1623		at_hint.s_node = 0;
1624		at_hint.s_net  = at->src_net;
1625
1626		rt = atrtr_find(&at_hint);
1627	}
1628	err = ENETUNREACH;
1629	if (!rt)
1630		goto out;
1631
1632	dev = rt->dev;
1633
1634	SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1635			sk, size, dev->name);
1636
1637	size += dev->hard_header_len;
1638	release_sock(sk);
1639	skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1640	lock_sock(sk);
1641	if (!skb)
1642		goto out;
1643
1644	skb_reserve(skb, ddp_dl->header_length);
1645	skb_reserve(skb, dev->hard_header_len);
1646	skb->dev = dev;
1647
1648	SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1649
1650	ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1651	ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1652	ddp->deh_dnet  = usat->sat_addr.s_net;
1653	ddp->deh_snet  = at->src_net;
1654	ddp->deh_dnode = usat->sat_addr.s_node;
1655	ddp->deh_snode = at->src_node;
1656	ddp->deh_dport = usat->sat_port;
1657	ddp->deh_sport = at->src_port;
1658
1659	SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1660
1661	err = memcpy_from_msg(skb_put(skb, len), msg, len);
1662	if (err) {
1663		kfree_skb(skb);
1664		err = -EFAULT;
1665		goto out;
1666	}
1667
1668	if (sk->sk_no_check_tx)
1669		ddp->deh_sum = 0;
1670	else
1671		ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1672
1673	/*
1674	 * Loopback broadcast packets to non gateway targets (ie routes
1675	 * to group we are in)
1676	 */
1677	if (ddp->deh_dnode == ATADDR_BCAST &&
1678	    !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1679		struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1680
1681		if (skb2) {
1682			loopback = 1;
1683			SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1684			/*
1685			 * If it fails it is queued/sent above in the aarp queue
1686			 */
1687			aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1688		}
1689	}
1690
1691	if (dev->flags & IFF_LOOPBACK || loopback) {
1692		SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1693		/* loop back */
1694		skb_orphan(skb);
1695		if (ddp->deh_dnode == ATADDR_BCAST) {
1696			struct atalk_addr at_lo;
1697
1698			at_lo.s_node = 0;
1699			at_lo.s_net  = 0;
1700
1701			rt = atrtr_find(&at_lo);
1702			if (!rt) {
1703				kfree_skb(skb);
1704				err = -ENETUNREACH;
1705				goto out;
1706			}
1707			dev = rt->dev;
1708			skb->dev = dev;
1709		}
1710		ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1711	} else {
1712		SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1713		if (rt->flags & RTF_GATEWAY) {
1714		    gsat.sat_addr = rt->gateway;
1715		    usat = &gsat;
1716		}
1717
1718		/*
1719		 * If it fails it is queued/sent above in the aarp queue
1720		 */
1721		aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1722	}
1723	SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1724
1725out:
1726	release_sock(sk);
1727	return err ? : len;
1728}
1729
1730static int atalk_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1731			 int flags)
1732{
1733	struct sock *sk = sock->sk;
1734	struct ddpehdr *ddp;
1735	int copied = 0;
1736	int offset = 0;
1737	int err = 0;
1738	struct sk_buff *skb;
1739
1740	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1741						flags & MSG_DONTWAIT, &err);
1742	lock_sock(sk);
1743
1744	if (!skb)
1745		goto out;
1746
1747	/* FIXME: use skb->cb to be able to use shared skbs */
1748	ddp = ddp_hdr(skb);
1749	copied = ntohs(ddp->deh_len_hops) & 1023;
1750
1751	if (sk->sk_type != SOCK_RAW) {
1752		offset = sizeof(*ddp);
1753		copied -= offset;
1754	}
1755
1756	if (copied > size) {
1757		copied = size;
1758		msg->msg_flags |= MSG_TRUNC;
1759	}
1760	err = skb_copy_datagram_msg(skb, offset, msg, copied);
1761
1762	if (!err && msg->msg_name) {
1763		DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
1764		sat->sat_family      = AF_APPLETALK;
1765		sat->sat_port        = ddp->deh_sport;
1766		sat->sat_addr.s_node = ddp->deh_snode;
1767		sat->sat_addr.s_net  = ddp->deh_snet;
1768		msg->msg_namelen     = sizeof(*sat);
1769	}
1770
1771	skb_free_datagram(sk, skb);	/* Free the datagram. */
1772
1773out:
1774	release_sock(sk);
1775	return err ? : copied;
1776}
1777
1778
1779/*
1780 * AppleTalk ioctl calls.
1781 */
1782static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1783{
1784	int rc = -ENOIOCTLCMD;
1785	struct sock *sk = sock->sk;
1786	void __user *argp = (void __user *)arg;
1787
1788	switch (cmd) {
1789	/* Protocol layer */
1790	case TIOCOUTQ: {
1791		long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1792
1793		if (amount < 0)
1794			amount = 0;
1795		rc = put_user(amount, (int __user *)argp);
1796		break;
1797	}
1798	case TIOCINQ: {
1799		/*
1800		 * These two are safe on a single CPU system as only
1801		 * user tasks fiddle here
1802		 */
1803		struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1804		long amount = 0;
1805
1806		if (skb)
1807			amount = skb->len - sizeof(struct ddpehdr);
1808		rc = put_user(amount, (int __user *)argp);
1809		break;
1810	}
1811	case SIOCGSTAMP:
1812		rc = sock_get_timestamp(sk, argp);
1813		break;
1814	case SIOCGSTAMPNS:
1815		rc = sock_get_timestampns(sk, argp);
1816		break;
1817	/* Routing */
1818	case SIOCADDRT:
1819	case SIOCDELRT:
1820		rc = -EPERM;
1821		if (capable(CAP_NET_ADMIN))
1822			rc = atrtr_ioctl(cmd, argp);
1823		break;
1824	/* Interface */
1825	case SIOCGIFADDR:
1826	case SIOCSIFADDR:
1827	case SIOCGIFBRDADDR:
1828	case SIOCATALKDIFADDR:
1829	case SIOCDIFADDR:
1830	case SIOCSARP:		/* proxy AARP */
1831	case SIOCDARP:		/* proxy AARP */
1832		rtnl_lock();
1833		rc = atif_ioctl(cmd, argp);
1834		rtnl_unlock();
1835		break;
1836	}
1837
1838	return rc;
1839}
1840
1841
1842#ifdef CONFIG_COMPAT
1843static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1844{
1845	/*
1846	 * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1847	 * cannot handle it in common code. The data we access if ifreq
1848	 * here is compatible, so we can simply call the native
1849	 * handler.
1850	 */
1851	if (cmd == SIOCATALKDIFADDR)
1852		return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
1853
1854	return -ENOIOCTLCMD;
1855}
1856#endif
1857
1858
1859static const struct net_proto_family atalk_family_ops = {
1860	.family		= PF_APPLETALK,
1861	.create		= atalk_create,
1862	.owner		= THIS_MODULE,
1863};
1864
1865static const struct proto_ops atalk_dgram_ops = {
1866	.family		= PF_APPLETALK,
1867	.owner		= THIS_MODULE,
1868	.release	= atalk_release,
1869	.bind		= atalk_bind,
1870	.connect	= atalk_connect,
1871	.socketpair	= sock_no_socketpair,
1872	.accept		= sock_no_accept,
1873	.getname	= atalk_getname,
1874	.poll		= datagram_poll,
1875	.ioctl		= atalk_ioctl,
1876#ifdef CONFIG_COMPAT
1877	.compat_ioctl	= atalk_compat_ioctl,
1878#endif
1879	.listen		= sock_no_listen,
1880	.shutdown	= sock_no_shutdown,
1881	.setsockopt	= sock_no_setsockopt,
1882	.getsockopt	= sock_no_getsockopt,
1883	.sendmsg	= atalk_sendmsg,
1884	.recvmsg	= atalk_recvmsg,
1885	.mmap		= sock_no_mmap,
1886	.sendpage	= sock_no_sendpage,
1887};
1888
1889static struct notifier_block ddp_notifier = {
1890	.notifier_call	= ddp_device_event,
1891};
1892
1893static struct packet_type ltalk_packet_type __read_mostly = {
1894	.type		= cpu_to_be16(ETH_P_LOCALTALK),
1895	.func		= ltalk_rcv,
1896};
1897
1898static struct packet_type ppptalk_packet_type __read_mostly = {
1899	.type		= cpu_to_be16(ETH_P_PPPTALK),
1900	.func		= atalk_rcv,
1901};
1902
1903static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1904
1905/* Export symbols for use by drivers when AppleTalk is a module */
1906EXPORT_SYMBOL(atrtr_get_dev);
1907EXPORT_SYMBOL(atalk_find_dev_addr);
1908
1909static const char atalk_err_snap[] __initconst =
1910	KERN_CRIT "Unable to register DDP with SNAP.\n";
1911
1912/* Called by proto.c on kernel start up */
1913static int __init atalk_init(void)
1914{
1915	int rc = proto_register(&ddp_proto, 0);
1916
1917	if (rc != 0)
1918		goto out;
1919
1920	(void)sock_register(&atalk_family_ops);
1921	ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1922	if (!ddp_dl)
1923		printk(atalk_err_snap);
1924
1925	dev_add_pack(&ltalk_packet_type);
1926	dev_add_pack(&ppptalk_packet_type);
1927
1928	register_netdevice_notifier(&ddp_notifier);
1929	aarp_proto_init();
1930	atalk_proc_init();
1931	atalk_register_sysctl();
1932out:
1933	return rc;
1934}
1935module_init(atalk_init);
1936
1937/*
1938 * No explicit module reference count manipulation is needed in the
1939 * protocol. Socket layer sets module reference count for us
1940 * and interfaces reference counting is done
1941 * by the network device layer.
1942 *
1943 * Ergo, before the AppleTalk module can be removed, all AppleTalk
1944 * sockets be closed from user space.
1945 */
1946static void __exit atalk_exit(void)
1947{
1948#ifdef CONFIG_SYSCTL
1949	atalk_unregister_sysctl();
1950#endif /* CONFIG_SYSCTL */
1951	atalk_proc_exit();
1952	aarp_cleanup_module();	/* General aarp clean-up. */
1953	unregister_netdevice_notifier(&ddp_notifier);
1954	dev_remove_pack(&ltalk_packet_type);
1955	dev_remove_pack(&ppptalk_packet_type);
1956	unregister_snap_client(ddp_dl);
1957	sock_unregister(PF_APPLETALK);
1958	proto_unregister(&ddp_proto);
1959}
1960module_exit(atalk_exit);
1961
1962MODULE_LICENSE("GPL");
1963MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
1964MODULE_DESCRIPTION("AppleTalk 0.20\n");
1965MODULE_ALIAS_NETPROTO(PF_APPLETALK);
1966