xref: /openbmc/linux/net/atm/clip.c (revision 4bdf0bb7)
1 /* net/atm/clip.c - RFC1577 Classical IP over ATM */
2 
3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4 
5 #include <linux/string.h>
6 #include <linux/errno.h>
7 #include <linux/kernel.h> /* for UINT_MAX */
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/netdevice.h>
11 #include <linux/skbuff.h>
12 #include <linux/wait.h>
13 #include <linux/timer.h>
14 #include <linux/if_arp.h> /* for some manifest constants */
15 #include <linux/notifier.h>
16 #include <linux/atm.h>
17 #include <linux/atmdev.h>
18 #include <linux/atmclip.h>
19 #include <linux/atmarp.h>
20 #include <linux/capability.h>
21 #include <linux/ip.h> /* for net/route.h */
22 #include <linux/in.h> /* for struct sockaddr_in */
23 #include <linux/if.h> /* for IFF_UP */
24 #include <linux/inetdevice.h>
25 #include <linux/bitops.h>
26 #include <linux/poison.h>
27 #include <linux/proc_fs.h>
28 #include <linux/seq_file.h>
29 #include <linux/rcupdate.h>
30 #include <linux/jhash.h>
31 #include <net/route.h> /* for struct rtable and routing */
32 #include <net/icmp.h> /* icmp_send */
33 #include <asm/param.h> /* for HZ */
34 #include <asm/byteorder.h> /* for htons etc. */
35 #include <asm/system.h> /* save/restore_flags */
36 #include <asm/uaccess.h>
37 #include <asm/atomic.h>
38 
39 #include "common.h"
40 #include "resources.h"
41 #include <net/atmclip.h>
42 
43 static struct net_device *clip_devs;
44 static struct atm_vcc *atmarpd;
45 static struct neigh_table clip_tbl;
46 static struct timer_list idle_timer;
47 
48 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
49 {
50 	struct sock *sk;
51 	struct atmarp_ctrl *ctrl;
52 	struct sk_buff *skb;
53 
54 	pr_debug("to_atmarpd(%d)\n", type);
55 	if (!atmarpd)
56 		return -EUNATCH;
57 	skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
58 	if (!skb)
59 		return -ENOMEM;
60 	ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
61 	ctrl->type = type;
62 	ctrl->itf_num = itf;
63 	ctrl->ip = ip;
64 	atm_force_charge(atmarpd, skb->truesize);
65 
66 	sk = sk_atm(atmarpd);
67 	skb_queue_tail(&sk->sk_receive_queue, skb);
68 	sk->sk_data_ready(sk, skb->len);
69 	return 0;
70 }
71 
72 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
73 {
74 	pr_debug("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
75 		entry->neigh);
76 	clip_vcc->entry = entry;
77 	clip_vcc->xoff = 0;	/* @@@ may overrun buffer by one packet */
78 	clip_vcc->next = entry->vccs;
79 	entry->vccs = clip_vcc;
80 	entry->neigh->used = jiffies;
81 }
82 
83 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
84 {
85 	struct atmarp_entry *entry = clip_vcc->entry;
86 	struct clip_vcc **walk;
87 
88 	if (!entry) {
89 		printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
90 		return;
91 	}
92 	netif_tx_lock_bh(entry->neigh->dev);	/* block clip_start_xmit() */
93 	entry->neigh->used = jiffies;
94 	for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
95 		if (*walk == clip_vcc) {
96 			int error;
97 
98 			*walk = clip_vcc->next;	/* atomic */
99 			clip_vcc->entry = NULL;
100 			if (clip_vcc->xoff)
101 				netif_wake_queue(entry->neigh->dev);
102 			if (entry->vccs)
103 				goto out;
104 			entry->expires = jiffies - 1;
105 			/* force resolution or expiration */
106 			error = neigh_update(entry->neigh, NULL, NUD_NONE,
107 					     NEIGH_UPDATE_F_ADMIN);
108 			if (error)
109 				printk(KERN_CRIT "unlink_clip_vcc: "
110 				       "neigh_update failed with %d\n", error);
111 			goto out;
112 		}
113 	printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
114 	       "0x%p)\n", entry, clip_vcc);
115       out:
116 	netif_tx_unlock_bh(entry->neigh->dev);
117 }
118 
119 /* The neighbour entry n->lock is held. */
120 static int neigh_check_cb(struct neighbour *n)
121 {
122 	struct atmarp_entry *entry = NEIGH2ENTRY(n);
123 	struct clip_vcc *cv;
124 
125 	for (cv = entry->vccs; cv; cv = cv->next) {
126 		unsigned long exp = cv->last_use + cv->idle_timeout;
127 
128 		if (cv->idle_timeout && time_after(jiffies, exp)) {
129 			pr_debug("releasing vcc %p->%p of entry %p\n",
130 				cv, cv->vcc, entry);
131 			vcc_release_async(cv->vcc, -ETIMEDOUT);
132 		}
133 	}
134 
135 	if (entry->vccs || time_before(jiffies, entry->expires))
136 		return 0;
137 
138 	if (atomic_read(&n->refcnt) > 1) {
139 		struct sk_buff *skb;
140 
141 		pr_debug("destruction postponed with ref %d\n",
142 			atomic_read(&n->refcnt));
143 
144 		while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
145 			dev_kfree_skb(skb);
146 
147 		return 0;
148 	}
149 
150 	pr_debug("expired neigh %p\n", n);
151 	return 1;
152 }
153 
154 static void idle_timer_check(unsigned long dummy)
155 {
156 	write_lock(&clip_tbl.lock);
157 	__neigh_for_each_release(&clip_tbl, neigh_check_cb);
158 	mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
159 	write_unlock(&clip_tbl.lock);
160 }
161 
162 static int clip_arp_rcv(struct sk_buff *skb)
163 {
164 	struct atm_vcc *vcc;
165 
166 	pr_debug("clip_arp_rcv\n");
167 	vcc = ATM_SKB(skb)->vcc;
168 	if (!vcc || !atm_charge(vcc, skb->truesize)) {
169 		dev_kfree_skb_any(skb);
170 		return 0;
171 	}
172 	pr_debug("pushing to %p\n", vcc);
173 	pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
174 	CLIP_VCC(vcc)->old_push(vcc, skb);
175 	return 0;
176 }
177 
178 static const unsigned char llc_oui[] = {
179 	0xaa,	/* DSAP: non-ISO */
180 	0xaa,	/* SSAP: non-ISO */
181 	0x03,	/* Ctrl: Unnumbered Information Command PDU */
182 	0x00,	/* OUI: EtherType */
183 	0x00,
184 	0x00
185 };
186 
187 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
188 {
189 	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
190 
191 	pr_debug("clip push\n");
192 	if (!skb) {
193 		pr_debug("removing VCC %p\n", clip_vcc);
194 		if (clip_vcc->entry)
195 			unlink_clip_vcc(clip_vcc);
196 		clip_vcc->old_push(vcc, NULL);	/* pass on the bad news */
197 		kfree(clip_vcc);
198 		return;
199 	}
200 	atm_return(vcc, skb->truesize);
201 	skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
202 	/* clip_vcc->entry == NULL if we don't have an IP address yet */
203 	if (!skb->dev) {
204 		dev_kfree_skb_any(skb);
205 		return;
206 	}
207 	ATM_SKB(skb)->vcc = vcc;
208 	skb_reset_mac_header(skb);
209 	if (!clip_vcc->encap
210 	    || skb->len < RFC1483LLC_LEN
211 	    || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
212 		skb->protocol = htons(ETH_P_IP);
213 	else {
214 		skb->protocol = ((__be16 *) skb->data)[3];
215 		skb_pull(skb, RFC1483LLC_LEN);
216 		if (skb->protocol == htons(ETH_P_ARP)) {
217 			skb->dev->stats.rx_packets++;
218 			skb->dev->stats.rx_bytes += skb->len;
219 			clip_arp_rcv(skb);
220 			return;
221 		}
222 	}
223 	clip_vcc->last_use = jiffies;
224 	skb->dev->stats.rx_packets++;
225 	skb->dev->stats.rx_bytes += skb->len;
226 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
227 	netif_rx(skb);
228 }
229 
230 /*
231  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
232  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
233  */
234 
235 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
236 {
237 	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
238 	struct net_device *dev = skb->dev;
239 	int old;
240 	unsigned long flags;
241 
242 	pr_debug("clip_pop(vcc %p)\n", vcc);
243 	clip_vcc->old_pop(vcc, skb);
244 	/* skb->dev == NULL in outbound ARP packets */
245 	if (!dev)
246 		return;
247 	spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
248 	if (atm_may_send(vcc, 0)) {
249 		old = xchg(&clip_vcc->xoff, 0);
250 		if (old)
251 			netif_wake_queue(dev);
252 	}
253 	spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
254 }
255 
256 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
257 {
258 	pr_debug("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
259 	to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
260 }
261 
262 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
263 {
264 #ifndef CONFIG_ATM_CLIP_NO_ICMP
265 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
266 #endif
267 	kfree_skb(skb);
268 }
269 
270 static const struct neigh_ops clip_neigh_ops = {
271 	.family =		AF_INET,
272 	.solicit =		clip_neigh_solicit,
273 	.error_report =		clip_neigh_error,
274 	.output =		dev_queue_xmit,
275 	.connected_output =	dev_queue_xmit,
276 	.hh_output =		dev_queue_xmit,
277 	.queue_xmit =		dev_queue_xmit,
278 };
279 
280 static int clip_constructor(struct neighbour *neigh)
281 {
282 	struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
283 	struct net_device *dev = neigh->dev;
284 	struct in_device *in_dev;
285 	struct neigh_parms *parms;
286 
287 	pr_debug("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
288 	neigh->type = inet_addr_type(&init_net, entry->ip);
289 	if (neigh->type != RTN_UNICAST)
290 		return -EINVAL;
291 
292 	rcu_read_lock();
293 	in_dev = __in_dev_get_rcu(dev);
294 	if (!in_dev) {
295 		rcu_read_unlock();
296 		return -EINVAL;
297 	}
298 
299 	parms = in_dev->arp_parms;
300 	__neigh_parms_put(neigh->parms);
301 	neigh->parms = neigh_parms_clone(parms);
302 	rcu_read_unlock();
303 
304 	neigh->ops = &clip_neigh_ops;
305 	neigh->output = neigh->nud_state & NUD_VALID ?
306 	    neigh->ops->connected_output : neigh->ops->output;
307 	entry->neigh = neigh;
308 	entry->vccs = NULL;
309 	entry->expires = jiffies - 1;
310 	return 0;
311 }
312 
313 static u32 clip_hash(const void *pkey, const struct net_device *dev)
314 {
315 	return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
316 }
317 
318 static struct neigh_table clip_tbl = {
319 	.family 	= AF_INET,
320 	.entry_size 	= sizeof(struct neighbour)+sizeof(struct atmarp_entry),
321 	.key_len 	= 4,
322 	.hash 		= clip_hash,
323 	.constructor 	= clip_constructor,
324 	.id 		= "clip_arp_cache",
325 
326 	/* parameters are copied from ARP ... */
327 	.parms = {
328 		.tbl 			= &clip_tbl,
329 		.base_reachable_time 	= 30 * HZ,
330 		.retrans_time 		= 1 * HZ,
331 		.gc_staletime 		= 60 * HZ,
332 		.reachable_time 	= 30 * HZ,
333 		.delay_probe_time 	= 5 * HZ,
334 		.queue_len 		= 3,
335 		.ucast_probes 		= 3,
336 		.mcast_probes 		= 3,
337 		.anycast_delay 		= 1 * HZ,
338 		.proxy_delay 		= (8 * HZ) / 10,
339 		.proxy_qlen 		= 64,
340 		.locktime 		= 1 * HZ,
341 	},
342 	.gc_interval 	= 30 * HZ,
343 	.gc_thresh1 	= 128,
344 	.gc_thresh2 	= 512,
345 	.gc_thresh3 	= 1024,
346 };
347 
348 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
349 
350 /*
351  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
352  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
353  * don't increment the usage count. This is used to create entries in
354  * clip_setentry.
355  */
356 
357 static int clip_encap(struct atm_vcc *vcc, int mode)
358 {
359 	CLIP_VCC(vcc)->encap = mode;
360 	return 0;
361 }
362 
363 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
364 				   struct net_device *dev)
365 {
366 	struct clip_priv *clip_priv = PRIV(dev);
367 	struct atmarp_entry *entry;
368 	struct atm_vcc *vcc;
369 	int old;
370 	unsigned long flags;
371 
372 	pr_debug("clip_start_xmit (skb %p)\n", skb);
373 	if (!skb_dst(skb)) {
374 		printk(KERN_ERR "clip_start_xmit: skb_dst(skb) == NULL\n");
375 		dev_kfree_skb(skb);
376 		dev->stats.tx_dropped++;
377 		return NETDEV_TX_OK;
378 	}
379 	if (!skb_dst(skb)->neighbour) {
380 #if 0
381 		skb_dst(skb)->neighbour = clip_find_neighbour(skb_dst(skb), 1);
382 		if (!skb_dst(skb)->neighbour) {
383 			dev_kfree_skb(skb);	/* lost that one */
384 			dev->stats.tx_dropped++;
385 			return 0;
386 		}
387 #endif
388 		printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
389 		dev_kfree_skb(skb);
390 		dev->stats.tx_dropped++;
391 		return NETDEV_TX_OK;
392 	}
393 	entry = NEIGH2ENTRY(skb_dst(skb)->neighbour);
394 	if (!entry->vccs) {
395 		if (time_after(jiffies, entry->expires)) {
396 			/* should be resolved */
397 			entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
398 			to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
399 		}
400 		if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
401 			skb_queue_tail(&entry->neigh->arp_queue, skb);
402 		else {
403 			dev_kfree_skb(skb);
404 			dev->stats.tx_dropped++;
405 		}
406 		return NETDEV_TX_OK;
407 	}
408 	pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
409 	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
410 	pr_debug("using neighbour %p, vcc %p\n", skb_dst(skb)->neighbour, vcc);
411 	if (entry->vccs->encap) {
412 		void *here;
413 
414 		here = skb_push(skb, RFC1483LLC_LEN);
415 		memcpy(here, llc_oui, sizeof(llc_oui));
416 		((__be16 *) here)[3] = skb->protocol;
417 	}
418 	atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
419 	ATM_SKB(skb)->atm_options = vcc->atm_options;
420 	entry->vccs->last_use = jiffies;
421 	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
422 	old = xchg(&entry->vccs->xoff, 1);	/* assume XOFF ... */
423 	if (old) {
424 		printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
425 		return NETDEV_TX_OK;
426 	}
427 	dev->stats.tx_packets++;
428 	dev->stats.tx_bytes += skb->len;
429 	vcc->send(vcc, skb);
430 	if (atm_may_send(vcc, 0)) {
431 		entry->vccs->xoff = 0;
432 		return NETDEV_TX_OK;
433 	}
434 	spin_lock_irqsave(&clip_priv->xoff_lock, flags);
435 	netif_stop_queue(dev);	/* XOFF -> throttle immediately */
436 	barrier();
437 	if (!entry->vccs->xoff)
438 		netif_start_queue(dev);
439 	/* Oh, we just raced with clip_pop. netif_start_queue should be
440 	   good enough, because nothing should really be asleep because
441 	   of the brief netif_stop_queue. If this isn't true or if it
442 	   changes, use netif_wake_queue instead. */
443 	spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
444 	return NETDEV_TX_OK;
445 }
446 
447 static int clip_mkip(struct atm_vcc *vcc, int timeout)
448 {
449 	struct sk_buff_head *rq, queue;
450 	struct clip_vcc *clip_vcc;
451 	struct sk_buff *skb, *tmp;
452 	unsigned long flags;
453 
454 	if (!vcc->push)
455 		return -EBADFD;
456 	clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
457 	if (!clip_vcc)
458 		return -ENOMEM;
459 	pr_debug("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
460 	clip_vcc->vcc = vcc;
461 	vcc->user_back = clip_vcc;
462 	set_bit(ATM_VF_IS_CLIP, &vcc->flags);
463 	clip_vcc->entry = NULL;
464 	clip_vcc->xoff = 0;
465 	clip_vcc->encap = 1;
466 	clip_vcc->last_use = jiffies;
467 	clip_vcc->idle_timeout = timeout * HZ;
468 	clip_vcc->old_push = vcc->push;
469 	clip_vcc->old_pop = vcc->pop;
470 	vcc->push = clip_push;
471 	vcc->pop = clip_pop;
472 
473 	__skb_queue_head_init(&queue);
474 	rq = &sk_atm(vcc)->sk_receive_queue;
475 
476 	spin_lock_irqsave(&rq->lock, flags);
477 	skb_queue_splice_init(rq, &queue);
478 	spin_unlock_irqrestore(&rq->lock, flags);
479 
480 	/* re-process everything received between connection setup and MKIP */
481 	skb_queue_walk_safe(&queue, skb, tmp) {
482 		if (!clip_devs) {
483 			atm_return(vcc, skb->truesize);
484 			kfree_skb(skb);
485 		} else {
486 			struct net_device *dev = skb->dev;
487 			unsigned int len = skb->len;
488 
489 			skb_get(skb);
490 			clip_push(vcc, skb);
491 			dev->stats.rx_packets--;
492 			dev->stats.rx_bytes -= len;
493 			kfree_skb(skb);
494 		}
495 	}
496 	return 0;
497 }
498 
499 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
500 {
501 	struct neighbour *neigh;
502 	struct atmarp_entry *entry;
503 	int error;
504 	struct clip_vcc *clip_vcc;
505 	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
506 	struct rtable *rt;
507 
508 	if (vcc->push != clip_push) {
509 		printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
510 		return -EBADF;
511 	}
512 	clip_vcc = CLIP_VCC(vcc);
513 	if (!ip) {
514 		if (!clip_vcc->entry) {
515 			printk(KERN_ERR "hiding hidden ATMARP entry\n");
516 			return 0;
517 		}
518 		pr_debug("setentry: remove\n");
519 		unlink_clip_vcc(clip_vcc);
520 		return 0;
521 	}
522 	error = ip_route_output_key(&init_net, &rt, &fl);
523 	if (error)
524 		return error;
525 	neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
526 	ip_rt_put(rt);
527 	if (!neigh)
528 		return -ENOMEM;
529 	entry = NEIGH2ENTRY(neigh);
530 	if (entry != clip_vcc->entry) {
531 		if (!clip_vcc->entry)
532 			pr_debug("setentry: add\n");
533 		else {
534 			pr_debug("setentry: update\n");
535 			unlink_clip_vcc(clip_vcc);
536 		}
537 		link_vcc(clip_vcc, entry);
538 	}
539 	error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
540 			     NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
541 	neigh_release(neigh);
542 	return error;
543 }
544 
545 static const struct net_device_ops clip_netdev_ops = {
546 	.ndo_start_xmit = clip_start_xmit,
547 };
548 
549 static void clip_setup(struct net_device *dev)
550 {
551 	dev->netdev_ops = &clip_netdev_ops;
552 	dev->type = ARPHRD_ATM;
553 	dev->hard_header_len = RFC1483LLC_LEN;
554 	dev->mtu = RFC1626_MTU;
555 	dev->tx_queue_len = 100;	/* "normal" queue (packets) */
556 	/* When using a "real" qdisc, the qdisc determines the queue */
557 	/* length. tx_queue_len is only used for the default case, */
558 	/* without any more elaborate queuing. 100 is a reasonable */
559 	/* compromise between decent burst-tolerance and protection */
560 	/* against memory hogs. */
561 	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
562 }
563 
564 static int clip_create(int number)
565 {
566 	struct net_device *dev;
567 	struct clip_priv *clip_priv;
568 	int error;
569 
570 	if (number != -1) {
571 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
572 			if (PRIV(dev)->number == number)
573 				return -EEXIST;
574 	} else {
575 		number = 0;
576 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
577 			if (PRIV(dev)->number >= number)
578 				number = PRIV(dev)->number + 1;
579 	}
580 	dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
581 	if (!dev)
582 		return -ENOMEM;
583 	clip_priv = PRIV(dev);
584 	sprintf(dev->name, "atm%d", number);
585 	spin_lock_init(&clip_priv->xoff_lock);
586 	clip_priv->number = number;
587 	error = register_netdev(dev);
588 	if (error) {
589 		free_netdev(dev);
590 		return error;
591 	}
592 	clip_priv->next = clip_devs;
593 	clip_devs = dev;
594 	pr_debug("registered (net:%s)\n", dev->name);
595 	return number;
596 }
597 
598 static int clip_device_event(struct notifier_block *this, unsigned long event,
599 			     void *arg)
600 {
601 	struct net_device *dev = arg;
602 
603 	if (!net_eq(dev_net(dev), &init_net))
604 		return NOTIFY_DONE;
605 
606 	if (event == NETDEV_UNREGISTER) {
607 		neigh_ifdown(&clip_tbl, dev);
608 		return NOTIFY_DONE;
609 	}
610 
611 	/* ignore non-CLIP devices */
612 	if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
613 		return NOTIFY_DONE;
614 
615 	switch (event) {
616 	case NETDEV_UP:
617 		pr_debug("clip_device_event NETDEV_UP\n");
618 		to_atmarpd(act_up, PRIV(dev)->number, 0);
619 		break;
620 	case NETDEV_GOING_DOWN:
621 		pr_debug("clip_device_event NETDEV_DOWN\n");
622 		to_atmarpd(act_down, PRIV(dev)->number, 0);
623 		break;
624 	case NETDEV_CHANGE:
625 	case NETDEV_CHANGEMTU:
626 		pr_debug("clip_device_event NETDEV_CHANGE*\n");
627 		to_atmarpd(act_change, PRIV(dev)->number, 0);
628 		break;
629 	}
630 	return NOTIFY_DONE;
631 }
632 
633 static int clip_inet_event(struct notifier_block *this, unsigned long event,
634 			   void *ifa)
635 {
636 	struct in_device *in_dev;
637 
638 	in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
639 	/*
640 	 * Transitions are of the down-change-up type, so it's sufficient to
641 	 * handle the change on up.
642 	 */
643 	if (event != NETDEV_UP)
644 		return NOTIFY_DONE;
645 	return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
646 }
647 
648 
649 static struct notifier_block clip_dev_notifier = {
650 	.notifier_call = clip_device_event,
651 };
652 
653 
654 
655 static struct notifier_block clip_inet_notifier = {
656 	.notifier_call = clip_inet_event,
657 };
658 
659 
660 
661 static void atmarpd_close(struct atm_vcc *vcc)
662 {
663 	pr_debug("atmarpd_close\n");
664 
665 	rtnl_lock();
666 	atmarpd = NULL;
667 	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
668 	rtnl_unlock();
669 
670 	pr_debug("(done)\n");
671 	module_put(THIS_MODULE);
672 }
673 
674 
675 static struct atmdev_ops atmarpd_dev_ops = {
676 	.close = atmarpd_close
677 };
678 
679 
680 static struct atm_dev atmarpd_dev = {
681 	.ops =			&atmarpd_dev_ops,
682 	.type =			"arpd",
683 	.number = 		999,
684 	.lock =			__SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
685 };
686 
687 
688 static int atm_init_atmarp(struct atm_vcc *vcc)
689 {
690 	rtnl_lock();
691 	if (atmarpd) {
692 		rtnl_unlock();
693 		return -EADDRINUSE;
694 	}
695 
696 	mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
697 
698 	atmarpd = vcc;
699 	set_bit(ATM_VF_META,&vcc->flags);
700 	set_bit(ATM_VF_READY,&vcc->flags);
701 	    /* allow replies and avoid getting closed if signaling dies */
702 	vcc->dev = &atmarpd_dev;
703 	vcc_insert_socket(sk_atm(vcc));
704 	vcc->push = NULL;
705 	vcc->pop = NULL; /* crash */
706 	vcc->push_oam = NULL; /* crash */
707 	rtnl_unlock();
708 	return 0;
709 }
710 
711 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
712 {
713 	struct atm_vcc *vcc = ATM_SD(sock);
714 	int err = 0;
715 
716 	switch (cmd) {
717 	case SIOCMKCLIP:
718 	case ATMARPD_CTRL:
719 	case ATMARP_MKIP:
720 	case ATMARP_SETENTRY:
721 	case ATMARP_ENCAP:
722 		if (!capable(CAP_NET_ADMIN))
723 			return -EPERM;
724 		break;
725 	default:
726 		return -ENOIOCTLCMD;
727 	}
728 
729 	switch (cmd) {
730 	case SIOCMKCLIP:
731 		err = clip_create(arg);
732 		break;
733 	case ATMARPD_CTRL:
734 		err = atm_init_atmarp(vcc);
735 		if (!err) {
736 			sock->state = SS_CONNECTED;
737 			__module_get(THIS_MODULE);
738 		}
739 		break;
740 	case ATMARP_MKIP:
741 		err = clip_mkip(vcc, arg);
742 		break;
743 	case ATMARP_SETENTRY:
744 		err = clip_setentry(vcc, (__force __be32)arg);
745 		break;
746 	case ATMARP_ENCAP:
747 		err = clip_encap(vcc, arg);
748 		break;
749 	}
750 	return err;
751 }
752 
753 static struct atm_ioctl clip_ioctl_ops = {
754 	.owner = THIS_MODULE,
755 	.ioctl = clip_ioctl,
756 };
757 
758 #ifdef CONFIG_PROC_FS
759 
760 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
761 {
762 	static int code[] = { 1, 2, 10, 6, 1, 0 };
763 	static int e164[] = { 1, 8, 4, 6, 1, 0 };
764 
765 	if (*addr->sas_addr.pub) {
766 		seq_printf(seq, "%s", addr->sas_addr.pub);
767 		if (*addr->sas_addr.prv)
768 			seq_putc(seq, '+');
769 	} else if (!*addr->sas_addr.prv) {
770 		seq_printf(seq, "%s", "(none)");
771 		return;
772 	}
773 	if (*addr->sas_addr.prv) {
774 		unsigned char *prv = addr->sas_addr.prv;
775 		int *fields;
776 		int i, j;
777 
778 		fields = *prv == ATM_AFI_E164 ? e164 : code;
779 		for (i = 0; fields[i]; i++) {
780 			for (j = fields[i]; j; j--)
781 				seq_printf(seq, "%02X", *prv++);
782 			if (fields[i + 1])
783 				seq_putc(seq, '.');
784 		}
785 	}
786 }
787 
788 /* This means the neighbour entry has no attached VCC objects. */
789 #define SEQ_NO_VCC_TOKEN	((void *) 2)
790 
791 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
792 			struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
793 {
794 	unsigned long exp;
795 	char buf[17];
796 	int svc, llc, off;
797 
798 	svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
799 	       (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
800 
801 	llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
802 
803 	if (clip_vcc == SEQ_NO_VCC_TOKEN)
804 		exp = entry->neigh->used;
805 	else
806 		exp = clip_vcc->last_use;
807 
808 	exp = (jiffies - exp) / HZ;
809 
810 	seq_printf(seq, "%-6s%-4s%-4s%5ld ",
811 		   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
812 
813 	off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
814 			&entry->ip);
815 	while (off < 16)
816 		buf[off++] = ' ';
817 	buf[off] = '\0';
818 	seq_printf(seq, "%s", buf);
819 
820 	if (clip_vcc == SEQ_NO_VCC_TOKEN) {
821 		if (time_before(jiffies, entry->expires))
822 			seq_printf(seq, "(resolving)\n");
823 		else
824 			seq_printf(seq, "(expired, ref %d)\n",
825 				   atomic_read(&entry->neigh->refcnt));
826 	} else if (!svc) {
827 		seq_printf(seq, "%d.%d.%d\n",
828 			   clip_vcc->vcc->dev->number,
829 			   clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
830 	} else {
831 		svc_addr(seq, &clip_vcc->vcc->remote);
832 		seq_putc(seq, '\n');
833 	}
834 }
835 
836 struct clip_seq_state {
837 	/* This member must be first. */
838 	struct neigh_seq_state ns;
839 
840 	/* Local to clip specific iteration. */
841 	struct clip_vcc *vcc;
842 };
843 
844 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
845 					  struct clip_vcc *curr)
846 {
847 	if (!curr) {
848 		curr = e->vccs;
849 		if (!curr)
850 			return SEQ_NO_VCC_TOKEN;
851 		return curr;
852 	}
853 	if (curr == SEQ_NO_VCC_TOKEN)
854 		return NULL;
855 
856 	curr = curr->next;
857 
858 	return curr;
859 }
860 
861 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
862 			       struct atmarp_entry *e, loff_t * pos)
863 {
864 	struct clip_vcc *vcc = state->vcc;
865 
866 	vcc = clip_seq_next_vcc(e, vcc);
867 	if (vcc && pos != NULL) {
868 		while (*pos) {
869 			vcc = clip_seq_next_vcc(e, vcc);
870 			if (!vcc)
871 				break;
872 			--(*pos);
873 		}
874 	}
875 	state->vcc = vcc;
876 
877 	return vcc;
878 }
879 
880 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
881 			       struct neighbour *n, loff_t * pos)
882 {
883 	struct clip_seq_state *state = (struct clip_seq_state *)_state;
884 
885 	return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
886 }
887 
888 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
889 {
890 	struct clip_seq_state *state = seq->private;
891 	state->ns.neigh_sub_iter = clip_seq_sub_iter;
892 	return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
893 }
894 
895 static int clip_seq_show(struct seq_file *seq, void *v)
896 {
897 	static char atm_arp_banner[] =
898 	    "IPitf TypeEncp Idle IP address      ATM address\n";
899 
900 	if (v == SEQ_START_TOKEN) {
901 		seq_puts(seq, atm_arp_banner);
902 	} else {
903 		struct clip_seq_state *state = seq->private;
904 		struct neighbour *n = v;
905 		struct clip_vcc *vcc = state->vcc;
906 
907 		atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
908 	}
909 	return 0;
910 }
911 
912 static const struct seq_operations arp_seq_ops = {
913 	.start	= clip_seq_start,
914 	.next	= neigh_seq_next,
915 	.stop	= neigh_seq_stop,
916 	.show	= clip_seq_show,
917 };
918 
919 static int arp_seq_open(struct inode *inode, struct file *file)
920 {
921 	return seq_open_net(inode, file, &arp_seq_ops,
922 			    sizeof(struct clip_seq_state));
923 }
924 
925 static const struct file_operations arp_seq_fops = {
926 	.open		= arp_seq_open,
927 	.read		= seq_read,
928 	.llseek		= seq_lseek,
929 	.release	= seq_release_net,
930 	.owner		= THIS_MODULE
931 };
932 #endif
933 
934 static void atm_clip_exit_noproc(void);
935 
936 static int __init atm_clip_init(void)
937 {
938 	neigh_table_init_no_netlink(&clip_tbl);
939 
940 	clip_tbl_hook = &clip_tbl;
941 	register_atm_ioctl(&clip_ioctl_ops);
942 	register_netdevice_notifier(&clip_dev_notifier);
943 	register_inetaddr_notifier(&clip_inet_notifier);
944 
945 	setup_timer(&idle_timer, idle_timer_check, 0);
946 
947 #ifdef CONFIG_PROC_FS
948 	{
949 		struct proc_dir_entry *p;
950 
951 		p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
952 		if (!p) {
953 			printk(KERN_ERR "Unable to initialize "
954 			       "/proc/net/atm/arp\n");
955 			atm_clip_exit_noproc();
956 			return -ENOMEM;
957 		}
958 	}
959 #endif
960 
961 	return 0;
962 }
963 
964 static void atm_clip_exit_noproc(void)
965 {
966 	struct net_device *dev, *next;
967 
968 	unregister_inetaddr_notifier(&clip_inet_notifier);
969 	unregister_netdevice_notifier(&clip_dev_notifier);
970 
971 	deregister_atm_ioctl(&clip_ioctl_ops);
972 
973 	/* First, stop the idle timer, so it stops banging
974 	 * on the table.
975 	 */
976 	del_timer_sync(&idle_timer);
977 
978 	/* Next, purge the table, so that the device
979 	 * unregister loop below does not hang due to
980 	 * device references remaining in the table.
981 	 */
982 	neigh_ifdown(&clip_tbl, NULL);
983 
984 	dev = clip_devs;
985 	while (dev) {
986 		next = PRIV(dev)->next;
987 		unregister_netdev(dev);
988 		free_netdev(dev);
989 		dev = next;
990 	}
991 
992 	/* Now it is safe to fully shutdown whole table. */
993 	neigh_table_clear(&clip_tbl);
994 
995 	clip_tbl_hook = NULL;
996 }
997 
998 static void __exit atm_clip_exit(void)
999 {
1000 	remove_proc_entry("arp", atm_proc_root);
1001 
1002 	atm_clip_exit_noproc();
1003 }
1004 
1005 module_init(atm_clip_init);
1006 module_exit(atm_clip_exit);
1007 MODULE_AUTHOR("Werner Almesberger");
1008 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1009 MODULE_LICENSE("GPL");
1010