1// SPDX-License-Identifier: GPL-2.0-only
2/* net/atm/clip.c - RFC1577 Classical IP over ATM */
3
4/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
7
8#include <linux/string.h>
9#include <linux/errno.h>
10#include <linux/kernel.h> /* for UINT_MAX */
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/netdevice.h>
14#include <linux/skbuff.h>
15#include <linux/wait.h>
16#include <linux/timer.h>
17#include <linux/if_arp.h> /* for some manifest constants */
18#include <linux/notifier.h>
19#include <linux/atm.h>
20#include <linux/atmdev.h>
21#include <linux/atmclip.h>
22#include <linux/atmarp.h>
23#include <linux/capability.h>
24#include <linux/ip.h> /* for net/route.h */
25#include <linux/in.h> /* for struct sockaddr_in */
26#include <linux/if.h> /* for IFF_UP */
27#include <linux/inetdevice.h>
28#include <linux/bitops.h>
29#include <linux/poison.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/rcupdate.h>
33#include <linux/jhash.h>
34#include <linux/slab.h>
35#include <net/route.h> /* for struct rtable and routing */
36#include <net/icmp.h> /* icmp_send */
37#include <net/arp.h>
38#include <linux/param.h> /* for HZ */
39#include <linux/uaccess.h>
40#include <asm/byteorder.h> /* for htons etc. */
41#include <linux/atomic.h>
42
43#include "common.h"
44#include "resources.h"
45#include <net/atmclip.h>
46
47static struct net_device *clip_devs;
48static struct atm_vcc *atmarpd;
49static struct timer_list idle_timer;
50static const struct neigh_ops clip_neigh_ops;
51
52static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
53{
54	struct sock *sk;
55	struct atmarp_ctrl *ctrl;
56	struct sk_buff *skb;
57
58	pr_debug("(%d)\n", type);
59	if (!atmarpd)
60		return -EUNATCH;
61	skb = alloc_skb(sizeof(struct atmarp_ctrl), GFP_ATOMIC);
62	if (!skb)
63		return -ENOMEM;
64	ctrl = skb_put(skb, sizeof(struct atmarp_ctrl));
65	ctrl->type = type;
66	ctrl->itf_num = itf;
67	ctrl->ip = ip;
68	atm_force_charge(atmarpd, skb->truesize);
69
70	sk = sk_atm(atmarpd);
71	skb_queue_tail(&sk->sk_receive_queue, skb);
72	sk->sk_data_ready(sk);
73	return 0;
74}
75
76static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
77{
78	pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh);
79	clip_vcc->entry = entry;
80	clip_vcc->xoff = 0;	/* @@@ may overrun buffer by one packet */
81	clip_vcc->next = entry->vccs;
82	entry->vccs = clip_vcc;
83	entry->neigh->used = jiffies;
84}
85
86static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
87{
88	struct atmarp_entry *entry = clip_vcc->entry;
89	struct clip_vcc **walk;
90
91	if (!entry) {
92		pr_err("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
93		return;
94	}
95	netif_tx_lock_bh(entry->neigh->dev);	/* block clip_start_xmit() */
96	entry->neigh->used = jiffies;
97	for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
98		if (*walk == clip_vcc) {
99			int error;
100
101			*walk = clip_vcc->next;	/* atomic */
102			clip_vcc->entry = NULL;
103			if (clip_vcc->xoff)
104				netif_wake_queue(entry->neigh->dev);
105			if (entry->vccs)
106				goto out;
107			entry->expires = jiffies - 1;
108			/* force resolution or expiration */
109			error = neigh_update(entry->neigh, NULL, NUD_NONE,
110					     NEIGH_UPDATE_F_ADMIN, 0);
111			if (error)
112				pr_err("neigh_update failed with %d\n", error);
113			goto out;
114		}
115	pr_err("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc);
116out:
117	netif_tx_unlock_bh(entry->neigh->dev);
118}
119
120/* The neighbour entry n->lock is held. */
121static int neigh_check_cb(struct neighbour *n)
122{
123	struct atmarp_entry *entry = neighbour_priv(n);
124	struct clip_vcc *cv;
125
126	if (n->ops != &clip_neigh_ops)
127		return 0;
128	for (cv = entry->vccs; cv; cv = cv->next) {
129		unsigned long exp = cv->last_use + cv->idle_timeout;
130
131		if (cv->idle_timeout && time_after(jiffies, exp)) {
132			pr_debug("releasing vcc %p->%p of entry %p\n",
133				 cv, cv->vcc, entry);
134			vcc_release_async(cv->vcc, -ETIMEDOUT);
135		}
136	}
137
138	if (entry->vccs || time_before(jiffies, entry->expires))
139		return 0;
140
141	if (refcount_read(&n->refcnt) > 1) {
142		struct sk_buff *skb;
143
144		pr_debug("destruction postponed with ref %d\n",
145			 refcount_read(&n->refcnt));
146
147		while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
148			dev_kfree_skb(skb);
149
150		return 0;
151	}
152
153	pr_debug("expired neigh %p\n", n);
154	return 1;
155}
156
157static void idle_timer_check(struct timer_list *unused)
158{
159	write_lock(&arp_tbl.lock);
160	__neigh_for_each_release(&arp_tbl, neigh_check_cb);
161	mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
162	write_unlock(&arp_tbl.lock);
163}
164
165static int clip_arp_rcv(struct sk_buff *skb)
166{
167	struct atm_vcc *vcc;
168
169	pr_debug("\n");
170	vcc = ATM_SKB(skb)->vcc;
171	if (!vcc || !atm_charge(vcc, skb->truesize)) {
172		dev_kfree_skb_any(skb);
173		return 0;
174	}
175	pr_debug("pushing to %p\n", vcc);
176	pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
177	CLIP_VCC(vcc)->old_push(vcc, skb);
178	return 0;
179}
180
181static const unsigned char llc_oui[] = {
182	0xaa,	/* DSAP: non-ISO */
183	0xaa,	/* SSAP: non-ISO */
184	0x03,	/* Ctrl: Unnumbered Information Command PDU */
185	0x00,	/* OUI: EtherType */
186	0x00,
187	0x00
188};
189
190static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
191{
192	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
193
194	pr_debug("\n");
195
196	if (!clip_devs) {
197		atm_return(vcc, skb->truesize);
198		kfree_skb(skb);
199		return;
200	}
201
202	if (!skb) {
203		pr_debug("removing VCC %p\n", clip_vcc);
204		if (clip_vcc->entry)
205			unlink_clip_vcc(clip_vcc);
206		clip_vcc->old_push(vcc, NULL);	/* pass on the bad news */
207		kfree(clip_vcc);
208		return;
209	}
210	atm_return(vcc, skb->truesize);
211	skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
212	/* clip_vcc->entry == NULL if we don't have an IP address yet */
213	if (!skb->dev) {
214		dev_kfree_skb_any(skb);
215		return;
216	}
217	ATM_SKB(skb)->vcc = vcc;
218	skb_reset_mac_header(skb);
219	if (!clip_vcc->encap ||
220	    skb->len < RFC1483LLC_LEN ||
221	    memcmp(skb->data, llc_oui, sizeof(llc_oui)))
222		skb->protocol = htons(ETH_P_IP);
223	else {
224		skb->protocol = ((__be16 *)skb->data)[3];
225		skb_pull(skb, RFC1483LLC_LEN);
226		if (skb->protocol == htons(ETH_P_ARP)) {
227			skb->dev->stats.rx_packets++;
228			skb->dev->stats.rx_bytes += skb->len;
229			clip_arp_rcv(skb);
230			return;
231		}
232	}
233	clip_vcc->last_use = jiffies;
234	skb->dev->stats.rx_packets++;
235	skb->dev->stats.rx_bytes += skb->len;
236	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
237	netif_rx(skb);
238}
239
240/*
241 * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
242 * clip_pop is atomic with respect to the critical section in clip_start_xmit.
243 */
244
245static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
246{
247	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
248	struct net_device *dev = skb->dev;
249	int old;
250	unsigned long flags;
251
252	pr_debug("(vcc %p)\n", vcc);
253	clip_vcc->old_pop(vcc, skb);
254	/* skb->dev == NULL in outbound ARP packets */
255	if (!dev)
256		return;
257	spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
258	if (atm_may_send(vcc, 0)) {
259		old = xchg(&clip_vcc->xoff, 0);
260		if (old)
261			netif_wake_queue(dev);
262	}
263	spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
264}
265
266static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
267{
268	__be32 *ip = (__be32 *) neigh->primary_key;
269
270	pr_debug("(neigh %p, skb %p)\n", neigh, skb);
271	to_atmarpd(act_need, PRIV(neigh->dev)->number, *ip);
272}
273
274static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
275{
276#ifndef CONFIG_ATM_CLIP_NO_ICMP
277	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
278#endif
279	kfree_skb(skb);
280}
281
282static const struct neigh_ops clip_neigh_ops = {
283	.family =		AF_INET,
284	.solicit =		clip_neigh_solicit,
285	.error_report =		clip_neigh_error,
286	.output =		neigh_direct_output,
287	.connected_output =	neigh_direct_output,
288};
289
290static int clip_constructor(struct net_device *dev, struct neighbour *neigh)
291{
292	struct atmarp_entry *entry = neighbour_priv(neigh);
293
294	if (neigh->tbl->family != AF_INET)
295		return -EINVAL;
296
297	if (neigh->type != RTN_UNICAST)
298		return -EINVAL;
299
300	neigh->nud_state = NUD_NONE;
301	neigh->ops = &clip_neigh_ops;
302	neigh->output = neigh->ops->output;
303	entry->neigh = neigh;
304	entry->vccs = NULL;
305	entry->expires = jiffies - 1;
306
307	return 0;
308}
309
310/* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
311
312/*
313 * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
314 * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
315 * don't increment the usage count. This is used to create entries in
316 * clip_setentry.
317 */
318
319static int clip_encap(struct atm_vcc *vcc, int mode)
320{
321	if (!CLIP_VCC(vcc))
322		return -EBADFD;
323
324	CLIP_VCC(vcc)->encap = mode;
325	return 0;
326}
327
328static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
329				   struct net_device *dev)
330{
331	struct clip_priv *clip_priv = PRIV(dev);
332	struct dst_entry *dst = skb_dst(skb);
333	struct atmarp_entry *entry;
334	struct neighbour *n;
335	struct atm_vcc *vcc;
336	struct rtable *rt;
337	__be32 *daddr;
338	int old;
339	unsigned long flags;
340
341	pr_debug("(skb %p)\n", skb);
342	if (!dst) {
343		pr_err("skb_dst(skb) == NULL\n");
344		dev_kfree_skb(skb);
345		dev->stats.tx_dropped++;
346		return NETDEV_TX_OK;
347	}
348	rt = (struct rtable *) dst;
349	if (rt->rt_gw_family == AF_INET)
350		daddr = &rt->rt_gw4;
351	else
352		daddr = &ip_hdr(skb)->daddr;
353	n = dst_neigh_lookup(dst, daddr);
354	if (!n) {
355		pr_err("NO NEIGHBOUR !\n");
356		dev_kfree_skb(skb);
357		dev->stats.tx_dropped++;
358		return NETDEV_TX_OK;
359	}
360	entry = neighbour_priv(n);
361	if (!entry->vccs) {
362		if (time_after(jiffies, entry->expires)) {
363			/* should be resolved */
364			entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
365			to_atmarpd(act_need, PRIV(dev)->number, *((__be32 *)n->primary_key));
366		}
367		if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
368			skb_queue_tail(&entry->neigh->arp_queue, skb);
369		else {
370			dev_kfree_skb(skb);
371			dev->stats.tx_dropped++;
372		}
373		goto out_release_neigh;
374	}
375	pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
376	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
377	pr_debug("using neighbour %p, vcc %p\n", n, vcc);
378	if (entry->vccs->encap) {
379		void *here;
380
381		here = skb_push(skb, RFC1483LLC_LEN);
382		memcpy(here, llc_oui, sizeof(llc_oui));
383		((__be16 *) here)[3] = skb->protocol;
384	}
385	atm_account_tx(vcc, skb);
386	entry->vccs->last_use = jiffies;
387	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
388	old = xchg(&entry->vccs->xoff, 1);	/* assume XOFF ... */
389	if (old) {
390		pr_warn("XOFF->XOFF transition\n");
391		goto out_release_neigh;
392	}
393	dev->stats.tx_packets++;
394	dev->stats.tx_bytes += skb->len;
395	vcc->send(vcc, skb);
396	if (atm_may_send(vcc, 0)) {
397		entry->vccs->xoff = 0;
398		goto out_release_neigh;
399	}
400	spin_lock_irqsave(&clip_priv->xoff_lock, flags);
401	netif_stop_queue(dev);	/* XOFF -> throttle immediately */
402	barrier();
403	if (!entry->vccs->xoff)
404		netif_start_queue(dev);
405	/* Oh, we just raced with clip_pop. netif_start_queue should be
406	   good enough, because nothing should really be asleep because
407	   of the brief netif_stop_queue. If this isn't true or if it
408	   changes, use netif_wake_queue instead. */
409	spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
410out_release_neigh:
411	neigh_release(n);
412	return NETDEV_TX_OK;
413}
414
415static int clip_mkip(struct atm_vcc *vcc, int timeout)
416{
417	struct clip_vcc *clip_vcc;
418
419	if (!vcc->push)
420		return -EBADFD;
421	clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
422	if (!clip_vcc)
423		return -ENOMEM;
424	pr_debug("%p vcc %p\n", clip_vcc, vcc);
425	clip_vcc->vcc = vcc;
426	vcc->user_back = clip_vcc;
427	set_bit(ATM_VF_IS_CLIP, &vcc->flags);
428	clip_vcc->entry = NULL;
429	clip_vcc->xoff = 0;
430	clip_vcc->encap = 1;
431	clip_vcc->last_use = jiffies;
432	clip_vcc->idle_timeout = timeout * HZ;
433	clip_vcc->old_push = vcc->push;
434	clip_vcc->old_pop = vcc->pop;
435	vcc->push = clip_push;
436	vcc->pop = clip_pop;
437
438	/* re-process everything received between connection setup and MKIP */
439	vcc_process_recv_queue(vcc);
440
441	return 0;
442}
443
444static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
445{
446	struct neighbour *neigh;
447	struct atmarp_entry *entry;
448	int error;
449	struct clip_vcc *clip_vcc;
450	struct rtable *rt;
451
452	if (vcc->push != clip_push) {
453		pr_warn("non-CLIP VCC\n");
454		return -EBADF;
455	}
456	clip_vcc = CLIP_VCC(vcc);
457	if (!ip) {
458		if (!clip_vcc->entry) {
459			pr_err("hiding hidden ATMARP entry\n");
460			return 0;
461		}
462		pr_debug("remove\n");
463		unlink_clip_vcc(clip_vcc);
464		return 0;
465	}
466	rt = ip_route_output(&init_net, ip, 0, 1, 0);
467	if (IS_ERR(rt))
468		return PTR_ERR(rt);
469	neigh = __neigh_lookup(&arp_tbl, &ip, rt->dst.dev, 1);
470	ip_rt_put(rt);
471	if (!neigh)
472		return -ENOMEM;
473	entry = neighbour_priv(neigh);
474	if (entry != clip_vcc->entry) {
475		if (!clip_vcc->entry)
476			pr_debug("add\n");
477		else {
478			pr_debug("update\n");
479			unlink_clip_vcc(clip_vcc);
480		}
481		link_vcc(clip_vcc, entry);
482	}
483	error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
484			     NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN, 0);
485	neigh_release(neigh);
486	return error;
487}
488
489static const struct net_device_ops clip_netdev_ops = {
490	.ndo_start_xmit		= clip_start_xmit,
491	.ndo_neigh_construct	= clip_constructor,
492};
493
494static void clip_setup(struct net_device *dev)
495{
496	dev->netdev_ops = &clip_netdev_ops;
497	dev->type = ARPHRD_ATM;
498	dev->neigh_priv_len = sizeof(struct atmarp_entry);
499	dev->hard_header_len = RFC1483LLC_LEN;
500	dev->mtu = RFC1626_MTU;
501	dev->tx_queue_len = 100;	/* "normal" queue (packets) */
502	/* When using a "real" qdisc, the qdisc determines the queue */
503	/* length. tx_queue_len is only used for the default case, */
504	/* without any more elaborate queuing. 100 is a reasonable */
505	/* compromise between decent burst-tolerance and protection */
506	/* against memory hogs. */
507	netif_keep_dst(dev);
508}
509
510static int clip_create(int number)
511{
512	struct net_device *dev;
513	struct clip_priv *clip_priv;
514	int error;
515
516	if (number != -1) {
517		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
518			if (PRIV(dev)->number == number)
519				return -EEXIST;
520	} else {
521		number = 0;
522		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
523			if (PRIV(dev)->number >= number)
524				number = PRIV(dev)->number + 1;
525	}
526	dev = alloc_netdev(sizeof(struct clip_priv), "", NET_NAME_UNKNOWN,
527			   clip_setup);
528	if (!dev)
529		return -ENOMEM;
530	clip_priv = PRIV(dev);
531	sprintf(dev->name, "atm%d", number);
532	spin_lock_init(&clip_priv->xoff_lock);
533	clip_priv->number = number;
534	error = register_netdev(dev);
535	if (error) {
536		free_netdev(dev);
537		return error;
538	}
539	clip_priv->next = clip_devs;
540	clip_devs = dev;
541	pr_debug("registered (net:%s)\n", dev->name);
542	return number;
543}
544
545static int clip_device_event(struct notifier_block *this, unsigned long event,
546			     void *ptr)
547{
548	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
549
550	if (!net_eq(dev_net(dev), &init_net))
551		return NOTIFY_DONE;
552
553	if (event == NETDEV_UNREGISTER)
554		return NOTIFY_DONE;
555
556	/* ignore non-CLIP devices */
557	if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
558		return NOTIFY_DONE;
559
560	switch (event) {
561	case NETDEV_UP:
562		pr_debug("NETDEV_UP\n");
563		to_atmarpd(act_up, PRIV(dev)->number, 0);
564		break;
565	case NETDEV_GOING_DOWN:
566		pr_debug("NETDEV_DOWN\n");
567		to_atmarpd(act_down, PRIV(dev)->number, 0);
568		break;
569	case NETDEV_CHANGE:
570	case NETDEV_CHANGEMTU:
571		pr_debug("NETDEV_CHANGE*\n");
572		to_atmarpd(act_change, PRIV(dev)->number, 0);
573		break;
574	}
575	return NOTIFY_DONE;
576}
577
578static int clip_inet_event(struct notifier_block *this, unsigned long event,
579			   void *ifa)
580{
581	struct in_device *in_dev;
582	struct netdev_notifier_info info;
583
584	in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
585	/*
586	 * Transitions are of the down-change-up type, so it's sufficient to
587	 * handle the change on up.
588	 */
589	if (event != NETDEV_UP)
590		return NOTIFY_DONE;
591	netdev_notifier_info_init(&info, in_dev->dev);
592	return clip_device_event(this, NETDEV_CHANGE, &info);
593}
594
595static struct notifier_block clip_dev_notifier = {
596	.notifier_call = clip_device_event,
597};
598
599
600
601static struct notifier_block clip_inet_notifier = {
602	.notifier_call = clip_inet_event,
603};
604
605
606
607static void atmarpd_close(struct atm_vcc *vcc)
608{
609	pr_debug("\n");
610
611	rtnl_lock();
612	atmarpd = NULL;
613	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
614	rtnl_unlock();
615
616	pr_debug("(done)\n");
617	module_put(THIS_MODULE);
618}
619
620static const struct atmdev_ops atmarpd_dev_ops = {
621	.close = atmarpd_close
622};
623
624
625static struct atm_dev atmarpd_dev = {
626	.ops =			&atmarpd_dev_ops,
627	.type =			"arpd",
628	.number = 		999,
629	.lock =			__SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
630};
631
632
633static int atm_init_atmarp(struct atm_vcc *vcc)
634{
635	rtnl_lock();
636	if (atmarpd) {
637		rtnl_unlock();
638		return -EADDRINUSE;
639	}
640
641	mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
642
643	atmarpd = vcc;
644	set_bit(ATM_VF_META, &vcc->flags);
645	set_bit(ATM_VF_READY, &vcc->flags);
646	    /* allow replies and avoid getting closed if signaling dies */
647	vcc->dev = &atmarpd_dev;
648	vcc_insert_socket(sk_atm(vcc));
649	vcc->push = NULL;
650	vcc->pop = NULL; /* crash */
651	vcc->push_oam = NULL; /* crash */
652	rtnl_unlock();
653	return 0;
654}
655
656static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
657{
658	struct atm_vcc *vcc = ATM_SD(sock);
659	int err = 0;
660
661	switch (cmd) {
662	case SIOCMKCLIP:
663	case ATMARPD_CTRL:
664	case ATMARP_MKIP:
665	case ATMARP_SETENTRY:
666	case ATMARP_ENCAP:
667		if (!capable(CAP_NET_ADMIN))
668			return -EPERM;
669		break;
670	default:
671		return -ENOIOCTLCMD;
672	}
673
674	switch (cmd) {
675	case SIOCMKCLIP:
676		err = clip_create(arg);
677		break;
678	case ATMARPD_CTRL:
679		err = atm_init_atmarp(vcc);
680		if (!err) {
681			sock->state = SS_CONNECTED;
682			__module_get(THIS_MODULE);
683		}
684		break;
685	case ATMARP_MKIP:
686		err = clip_mkip(vcc, arg);
687		break;
688	case ATMARP_SETENTRY:
689		err = clip_setentry(vcc, (__force __be32)arg);
690		break;
691	case ATMARP_ENCAP:
692		err = clip_encap(vcc, arg);
693		break;
694	}
695	return err;
696}
697
698static struct atm_ioctl clip_ioctl_ops = {
699	.owner = THIS_MODULE,
700	.ioctl = clip_ioctl,
701};
702
703#ifdef CONFIG_PROC_FS
704
705static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
706{
707	static int code[] = { 1, 2, 10, 6, 1, 0 };
708	static int e164[] = { 1, 8, 4, 6, 1, 0 };
709
710	if (*addr->sas_addr.pub) {
711		seq_printf(seq, "%s", addr->sas_addr.pub);
712		if (*addr->sas_addr.prv)
713			seq_putc(seq, '+');
714	} else if (!*addr->sas_addr.prv) {
715		seq_printf(seq, "%s", "(none)");
716		return;
717	}
718	if (*addr->sas_addr.prv) {
719		unsigned char *prv = addr->sas_addr.prv;
720		int *fields;
721		int i, j;
722
723		fields = *prv == ATM_AFI_E164 ? e164 : code;
724		for (i = 0; fields[i]; i++) {
725			for (j = fields[i]; j; j--)
726				seq_printf(seq, "%02X", *prv++);
727			if (fields[i + 1])
728				seq_putc(seq, '.');
729		}
730	}
731}
732
733/* This means the neighbour entry has no attached VCC objects. */
734#define SEQ_NO_VCC_TOKEN	((void *) 2)
735
736static void atmarp_info(struct seq_file *seq, struct neighbour *n,
737			struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
738{
739	struct net_device *dev = n->dev;
740	unsigned long exp;
741	char buf[17];
742	int svc, llc, off;
743
744	svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
745	       (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
746
747	llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
748
749	if (clip_vcc == SEQ_NO_VCC_TOKEN)
750		exp = entry->neigh->used;
751	else
752		exp = clip_vcc->last_use;
753
754	exp = (jiffies - exp) / HZ;
755
756	seq_printf(seq, "%-6s%-4s%-4s%5ld ",
757		   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
758
759	off = scnprintf(buf, sizeof(buf) - 1, "%pI4", n->primary_key);
760	while (off < 16)
761		buf[off++] = ' ';
762	buf[off] = '\0';
763	seq_printf(seq, "%s", buf);
764
765	if (clip_vcc == SEQ_NO_VCC_TOKEN) {
766		if (time_before(jiffies, entry->expires))
767			seq_printf(seq, "(resolving)\n");
768		else
769			seq_printf(seq, "(expired, ref %d)\n",
770				   refcount_read(&entry->neigh->refcnt));
771	} else if (!svc) {
772		seq_printf(seq, "%d.%d.%d\n",
773			   clip_vcc->vcc->dev->number,
774			   clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
775	} else {
776		svc_addr(seq, &clip_vcc->vcc->remote);
777		seq_putc(seq, '\n');
778	}
779}
780
781struct clip_seq_state {
782	/* This member must be first. */
783	struct neigh_seq_state ns;
784
785	/* Local to clip specific iteration. */
786	struct clip_vcc *vcc;
787};
788
789static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
790					  struct clip_vcc *curr)
791{
792	if (!curr) {
793		curr = e->vccs;
794		if (!curr)
795			return SEQ_NO_VCC_TOKEN;
796		return curr;
797	}
798	if (curr == SEQ_NO_VCC_TOKEN)
799		return NULL;
800
801	curr = curr->next;
802
803	return curr;
804}
805
806static void *clip_seq_vcc_walk(struct clip_seq_state *state,
807			       struct atmarp_entry *e, loff_t * pos)
808{
809	struct clip_vcc *vcc = state->vcc;
810
811	vcc = clip_seq_next_vcc(e, vcc);
812	if (vcc && pos != NULL) {
813		while (*pos) {
814			vcc = clip_seq_next_vcc(e, vcc);
815			if (!vcc)
816				break;
817			--(*pos);
818		}
819	}
820	state->vcc = vcc;
821
822	return vcc;
823}
824
825static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
826			       struct neighbour *n, loff_t * pos)
827{
828	struct clip_seq_state *state = (struct clip_seq_state *)_state;
829
830	if (n->dev->type != ARPHRD_ATM)
831		return NULL;
832
833	return clip_seq_vcc_walk(state, neighbour_priv(n), pos);
834}
835
836static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
837{
838	struct clip_seq_state *state = seq->private;
839	state->ns.neigh_sub_iter = clip_seq_sub_iter;
840	return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_NEIGH_ONLY);
841}
842
843static int clip_seq_show(struct seq_file *seq, void *v)
844{
845	static char atm_arp_banner[] =
846	    "IPitf TypeEncp Idle IP address      ATM address\n";
847
848	if (v == SEQ_START_TOKEN) {
849		seq_puts(seq, atm_arp_banner);
850	} else {
851		struct clip_seq_state *state = seq->private;
852		struct clip_vcc *vcc = state->vcc;
853		struct neighbour *n = v;
854
855		atmarp_info(seq, n, neighbour_priv(n), vcc);
856	}
857	return 0;
858}
859
860static const struct seq_operations arp_seq_ops = {
861	.start	= clip_seq_start,
862	.next	= neigh_seq_next,
863	.stop	= neigh_seq_stop,
864	.show	= clip_seq_show,
865};
866#endif
867
868static void atm_clip_exit_noproc(void);
869
870static int __init atm_clip_init(void)
871{
872	register_atm_ioctl(&clip_ioctl_ops);
873	register_netdevice_notifier(&clip_dev_notifier);
874	register_inetaddr_notifier(&clip_inet_notifier);
875
876	timer_setup(&idle_timer, idle_timer_check, 0);
877
878#ifdef CONFIG_PROC_FS
879	{
880		struct proc_dir_entry *p;
881
882		p = proc_create_net("arp", 0444, atm_proc_root, &arp_seq_ops,
883				sizeof(struct clip_seq_state));
884		if (!p) {
885			pr_err("Unable to initialize /proc/net/atm/arp\n");
886			atm_clip_exit_noproc();
887			return -ENOMEM;
888		}
889	}
890#endif
891
892	return 0;
893}
894
895static void atm_clip_exit_noproc(void)
896{
897	struct net_device *dev, *next;
898
899	unregister_inetaddr_notifier(&clip_inet_notifier);
900	unregister_netdevice_notifier(&clip_dev_notifier);
901
902	deregister_atm_ioctl(&clip_ioctl_ops);
903
904	/* First, stop the idle timer, so it stops banging
905	 * on the table.
906	 */
907	del_timer_sync(&idle_timer);
908
909	dev = clip_devs;
910	while (dev) {
911		next = PRIV(dev)->next;
912		unregister_netdev(dev);
913		free_netdev(dev);
914		dev = next;
915	}
916}
917
918static void __exit atm_clip_exit(void)
919{
920	remove_proc_entry("arp", atm_proc_root);
921
922	atm_clip_exit_noproc();
923}
924
925module_init(atm_clip_init);
926module_exit(atm_clip_exit);
927MODULE_AUTHOR("Werner Almesberger");
928MODULE_DESCRIPTION("Classical/IP over ATM interface");
929MODULE_LICENSE("GPL");
930