xref: /openbmc/linux/net/atm/clip.c (revision 82ced6fd)
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 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 int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
364 {
365 	struct clip_priv *clip_priv = PRIV(dev);
366 	struct atmarp_entry *entry;
367 	struct atm_vcc *vcc;
368 	int old;
369 	unsigned long flags;
370 
371 	pr_debug("clip_start_xmit (skb %p)\n", skb);
372 	if (!skb->dst) {
373 		printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
374 		dev_kfree_skb(skb);
375 		dev->stats.tx_dropped++;
376 		return 0;
377 	}
378 	if (!skb->dst->neighbour) {
379 #if 0
380 		skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
381 		if (!skb->dst->neighbour) {
382 			dev_kfree_skb(skb);	/* lost that one */
383 			dev->stats.tx_dropped++;
384 			return 0;
385 		}
386 #endif
387 		printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
388 		dev_kfree_skb(skb);
389 		dev->stats.tx_dropped++;
390 		return 0;
391 	}
392 	entry = NEIGH2ENTRY(skb->dst->neighbour);
393 	if (!entry->vccs) {
394 		if (time_after(jiffies, entry->expires)) {
395 			/* should be resolved */
396 			entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
397 			to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
398 		}
399 		if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
400 			skb_queue_tail(&entry->neigh->arp_queue, skb);
401 		else {
402 			dev_kfree_skb(skb);
403 			dev->stats.tx_dropped++;
404 		}
405 		return 0;
406 	}
407 	pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
408 	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
409 	pr_debug("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
410 	if (entry->vccs->encap) {
411 		void *here;
412 
413 		here = skb_push(skb, RFC1483LLC_LEN);
414 		memcpy(here, llc_oui, sizeof(llc_oui));
415 		((__be16 *) here)[3] = skb->protocol;
416 	}
417 	atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
418 	ATM_SKB(skb)->atm_options = vcc->atm_options;
419 	entry->vccs->last_use = jiffies;
420 	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
421 	old = xchg(&entry->vccs->xoff, 1);	/* assume XOFF ... */
422 	if (old) {
423 		printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
424 		return 0;
425 	}
426 	dev->stats.tx_packets++;
427 	dev->stats.tx_bytes += skb->len;
428 	vcc->send(vcc, skb);
429 	if (atm_may_send(vcc, 0)) {
430 		entry->vccs->xoff = 0;
431 		return 0;
432 	}
433 	spin_lock_irqsave(&clip_priv->xoff_lock, flags);
434 	netif_stop_queue(dev);	/* XOFF -> throttle immediately */
435 	barrier();
436 	if (!entry->vccs->xoff)
437 		netif_start_queue(dev);
438 	/* Oh, we just raced with clip_pop. netif_start_queue should be
439 	   good enough, because nothing should really be asleep because
440 	   of the brief netif_stop_queue. If this isn't true or if it
441 	   changes, use netif_wake_queue instead. */
442 	spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
443 	return 0;
444 }
445 
446 static int clip_mkip(struct atm_vcc *vcc, int timeout)
447 {
448 	struct clip_vcc *clip_vcc;
449 	struct sk_buff *skb;
450 	struct sk_buff_head *rq;
451 	unsigned long flags;
452 
453 	if (!vcc->push)
454 		return -EBADFD;
455 	clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
456 	if (!clip_vcc)
457 		return -ENOMEM;
458 	pr_debug("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
459 	clip_vcc->vcc = vcc;
460 	vcc->user_back = clip_vcc;
461 	set_bit(ATM_VF_IS_CLIP, &vcc->flags);
462 	clip_vcc->entry = NULL;
463 	clip_vcc->xoff = 0;
464 	clip_vcc->encap = 1;
465 	clip_vcc->last_use = jiffies;
466 	clip_vcc->idle_timeout = timeout * HZ;
467 	clip_vcc->old_push = vcc->push;
468 	clip_vcc->old_pop = vcc->pop;
469 	vcc->push = clip_push;
470 	vcc->pop = clip_pop;
471 
472 	rq = &sk_atm(vcc)->sk_receive_queue;
473 
474 	spin_lock_irqsave(&rq->lock, flags);
475 	if (skb_queue_empty(rq)) {
476 		skb = NULL;
477 	} else {
478 		/* NULL terminate the list.  */
479 		rq->prev->next = NULL;
480 		skb = rq->next;
481 	}
482 	rq->prev = rq->next = (struct sk_buff *)rq;
483 	rq->qlen = 0;
484 	spin_unlock_irqrestore(&rq->lock, flags);
485 
486 	/* re-process everything received between connection setup and MKIP */
487 	while (skb) {
488 		struct sk_buff *next = skb->next;
489 
490 		skb->next = skb->prev = NULL;
491 		if (!clip_devs) {
492 			atm_return(vcc, skb->truesize);
493 			kfree_skb(skb);
494 		} else {
495 			unsigned int len = skb->len;
496 
497 			skb_get(skb);
498 			clip_push(vcc, skb);
499 			skb->dev->stats.rx_packets--;
500 			skb->dev->stats.rx_bytes -= len;
501 			kfree_skb(skb);
502 		}
503 
504 		skb = next;
505 	}
506 	return 0;
507 }
508 
509 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
510 {
511 	struct neighbour *neigh;
512 	struct atmarp_entry *entry;
513 	int error;
514 	struct clip_vcc *clip_vcc;
515 	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
516 	struct rtable *rt;
517 
518 	if (vcc->push != clip_push) {
519 		printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
520 		return -EBADF;
521 	}
522 	clip_vcc = CLIP_VCC(vcc);
523 	if (!ip) {
524 		if (!clip_vcc->entry) {
525 			printk(KERN_ERR "hiding hidden ATMARP entry\n");
526 			return 0;
527 		}
528 		pr_debug("setentry: remove\n");
529 		unlink_clip_vcc(clip_vcc);
530 		return 0;
531 	}
532 	error = ip_route_output_key(&init_net, &rt, &fl);
533 	if (error)
534 		return error;
535 	neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
536 	ip_rt_put(rt);
537 	if (!neigh)
538 		return -ENOMEM;
539 	entry = NEIGH2ENTRY(neigh);
540 	if (entry != clip_vcc->entry) {
541 		if (!clip_vcc->entry)
542 			pr_debug("setentry: add\n");
543 		else {
544 			pr_debug("setentry: update\n");
545 			unlink_clip_vcc(clip_vcc);
546 		}
547 		link_vcc(clip_vcc, entry);
548 	}
549 	error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
550 			     NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
551 	neigh_release(neigh);
552 	return error;
553 }
554 
555 static const struct net_device_ops clip_netdev_ops = {
556 	.ndo_start_xmit = clip_start_xmit,
557 };
558 
559 static void clip_setup(struct net_device *dev)
560 {
561 	dev->netdev_ops = &clip_netdev_ops;
562 	dev->type = ARPHRD_ATM;
563 	dev->hard_header_len = RFC1483LLC_LEN;
564 	dev->mtu = RFC1626_MTU;
565 	dev->tx_queue_len = 100;	/* "normal" queue (packets) */
566 	/* When using a "real" qdisc, the qdisc determines the queue */
567 	/* length. tx_queue_len is only used for the default case, */
568 	/* without any more elaborate queuing. 100 is a reasonable */
569 	/* compromise between decent burst-tolerance and protection */
570 	/* against memory hogs. */
571 }
572 
573 static int clip_create(int number)
574 {
575 	struct net_device *dev;
576 	struct clip_priv *clip_priv;
577 	int error;
578 
579 	if (number != -1) {
580 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
581 			if (PRIV(dev)->number == number)
582 				return -EEXIST;
583 	} else {
584 		number = 0;
585 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
586 			if (PRIV(dev)->number >= number)
587 				number = PRIV(dev)->number + 1;
588 	}
589 	dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
590 	if (!dev)
591 		return -ENOMEM;
592 	clip_priv = PRIV(dev);
593 	sprintf(dev->name, "atm%d", number);
594 	spin_lock_init(&clip_priv->xoff_lock);
595 	clip_priv->number = number;
596 	error = register_netdev(dev);
597 	if (error) {
598 		free_netdev(dev);
599 		return error;
600 	}
601 	clip_priv->next = clip_devs;
602 	clip_devs = dev;
603 	pr_debug("registered (net:%s)\n", dev->name);
604 	return number;
605 }
606 
607 static int clip_device_event(struct notifier_block *this, unsigned long event,
608 			     void *arg)
609 {
610 	struct net_device *dev = arg;
611 
612 	if (!net_eq(dev_net(dev), &init_net))
613 		return NOTIFY_DONE;
614 
615 	if (event == NETDEV_UNREGISTER) {
616 		neigh_ifdown(&clip_tbl, dev);
617 		return NOTIFY_DONE;
618 	}
619 
620 	/* ignore non-CLIP devices */
621 	if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
622 		return NOTIFY_DONE;
623 
624 	switch (event) {
625 	case NETDEV_UP:
626 		pr_debug("clip_device_event NETDEV_UP\n");
627 		to_atmarpd(act_up, PRIV(dev)->number, 0);
628 		break;
629 	case NETDEV_GOING_DOWN:
630 		pr_debug("clip_device_event NETDEV_DOWN\n");
631 		to_atmarpd(act_down, PRIV(dev)->number, 0);
632 		break;
633 	case NETDEV_CHANGE:
634 	case NETDEV_CHANGEMTU:
635 		pr_debug("clip_device_event NETDEV_CHANGE*\n");
636 		to_atmarpd(act_change, PRIV(dev)->number, 0);
637 		break;
638 	}
639 	return NOTIFY_DONE;
640 }
641 
642 static int clip_inet_event(struct notifier_block *this, unsigned long event,
643 			   void *ifa)
644 {
645 	struct in_device *in_dev;
646 
647 	in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
648 	/*
649 	 * Transitions are of the down-change-up type, so it's sufficient to
650 	 * handle the change on up.
651 	 */
652 	if (event != NETDEV_UP)
653 		return NOTIFY_DONE;
654 	return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
655 }
656 
657 
658 static struct notifier_block clip_dev_notifier = {
659 	.notifier_call = clip_device_event,
660 };
661 
662 
663 
664 static struct notifier_block clip_inet_notifier = {
665 	.notifier_call = clip_inet_event,
666 };
667 
668 
669 
670 static void atmarpd_close(struct atm_vcc *vcc)
671 {
672 	pr_debug("atmarpd_close\n");
673 
674 	rtnl_lock();
675 	atmarpd = NULL;
676 	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
677 	rtnl_unlock();
678 
679 	pr_debug("(done)\n");
680 	module_put(THIS_MODULE);
681 }
682 
683 
684 static struct atmdev_ops atmarpd_dev_ops = {
685 	.close = atmarpd_close
686 };
687 
688 
689 static struct atm_dev atmarpd_dev = {
690 	.ops =			&atmarpd_dev_ops,
691 	.type =			"arpd",
692 	.number = 		999,
693 	.lock =			__SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
694 };
695 
696 
697 static int atm_init_atmarp(struct atm_vcc *vcc)
698 {
699 	rtnl_lock();
700 	if (atmarpd) {
701 		rtnl_unlock();
702 		return -EADDRINUSE;
703 	}
704 
705 	mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
706 
707 	atmarpd = vcc;
708 	set_bit(ATM_VF_META,&vcc->flags);
709 	set_bit(ATM_VF_READY,&vcc->flags);
710 	    /* allow replies and avoid getting closed if signaling dies */
711 	vcc->dev = &atmarpd_dev;
712 	vcc_insert_socket(sk_atm(vcc));
713 	vcc->push = NULL;
714 	vcc->pop = NULL; /* crash */
715 	vcc->push_oam = NULL; /* crash */
716 	rtnl_unlock();
717 	return 0;
718 }
719 
720 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
721 {
722 	struct atm_vcc *vcc = ATM_SD(sock);
723 	int err = 0;
724 
725 	switch (cmd) {
726 	case SIOCMKCLIP:
727 	case ATMARPD_CTRL:
728 	case ATMARP_MKIP:
729 	case ATMARP_SETENTRY:
730 	case ATMARP_ENCAP:
731 		if (!capable(CAP_NET_ADMIN))
732 			return -EPERM;
733 		break;
734 	default:
735 		return -ENOIOCTLCMD;
736 	}
737 
738 	switch (cmd) {
739 	case SIOCMKCLIP:
740 		err = clip_create(arg);
741 		break;
742 	case ATMARPD_CTRL:
743 		err = atm_init_atmarp(vcc);
744 		if (!err) {
745 			sock->state = SS_CONNECTED;
746 			__module_get(THIS_MODULE);
747 		}
748 		break;
749 	case ATMARP_MKIP:
750 		err = clip_mkip(vcc, arg);
751 		break;
752 	case ATMARP_SETENTRY:
753 		err = clip_setentry(vcc, (__force __be32)arg);
754 		break;
755 	case ATMARP_ENCAP:
756 		err = clip_encap(vcc, arg);
757 		break;
758 	}
759 	return err;
760 }
761 
762 static struct atm_ioctl clip_ioctl_ops = {
763 	.owner = THIS_MODULE,
764 	.ioctl = clip_ioctl,
765 };
766 
767 #ifdef CONFIG_PROC_FS
768 
769 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
770 {
771 	static int code[] = { 1, 2, 10, 6, 1, 0 };
772 	static int e164[] = { 1, 8, 4, 6, 1, 0 };
773 
774 	if (*addr->sas_addr.pub) {
775 		seq_printf(seq, "%s", addr->sas_addr.pub);
776 		if (*addr->sas_addr.prv)
777 			seq_putc(seq, '+');
778 	} else if (!*addr->sas_addr.prv) {
779 		seq_printf(seq, "%s", "(none)");
780 		return;
781 	}
782 	if (*addr->sas_addr.prv) {
783 		unsigned char *prv = addr->sas_addr.prv;
784 		int *fields;
785 		int i, j;
786 
787 		fields = *prv == ATM_AFI_E164 ? e164 : code;
788 		for (i = 0; fields[i]; i++) {
789 			for (j = fields[i]; j; j--)
790 				seq_printf(seq, "%02X", *prv++);
791 			if (fields[i + 1])
792 				seq_putc(seq, '.');
793 		}
794 	}
795 }
796 
797 /* This means the neighbour entry has no attached VCC objects. */
798 #define SEQ_NO_VCC_TOKEN	((void *) 2)
799 
800 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
801 			struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
802 {
803 	unsigned long exp;
804 	char buf[17];
805 	int svc, llc, off;
806 
807 	svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
808 	       (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
809 
810 	llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
811 
812 	if (clip_vcc == SEQ_NO_VCC_TOKEN)
813 		exp = entry->neigh->used;
814 	else
815 		exp = clip_vcc->last_use;
816 
817 	exp = (jiffies - exp) / HZ;
818 
819 	seq_printf(seq, "%-6s%-4s%-4s%5ld ",
820 		   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
821 
822 	off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
823 			&entry->ip);
824 	while (off < 16)
825 		buf[off++] = ' ';
826 	buf[off] = '\0';
827 	seq_printf(seq, "%s", buf);
828 
829 	if (clip_vcc == SEQ_NO_VCC_TOKEN) {
830 		if (time_before(jiffies, entry->expires))
831 			seq_printf(seq, "(resolving)\n");
832 		else
833 			seq_printf(seq, "(expired, ref %d)\n",
834 				   atomic_read(&entry->neigh->refcnt));
835 	} else if (!svc) {
836 		seq_printf(seq, "%d.%d.%d\n",
837 			   clip_vcc->vcc->dev->number,
838 			   clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
839 	} else {
840 		svc_addr(seq, &clip_vcc->vcc->remote);
841 		seq_putc(seq, '\n');
842 	}
843 }
844 
845 struct clip_seq_state {
846 	/* This member must be first. */
847 	struct neigh_seq_state ns;
848 
849 	/* Local to clip specific iteration. */
850 	struct clip_vcc *vcc;
851 };
852 
853 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
854 					  struct clip_vcc *curr)
855 {
856 	if (!curr) {
857 		curr = e->vccs;
858 		if (!curr)
859 			return SEQ_NO_VCC_TOKEN;
860 		return curr;
861 	}
862 	if (curr == SEQ_NO_VCC_TOKEN)
863 		return NULL;
864 
865 	curr = curr->next;
866 
867 	return curr;
868 }
869 
870 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
871 			       struct atmarp_entry *e, loff_t * pos)
872 {
873 	struct clip_vcc *vcc = state->vcc;
874 
875 	vcc = clip_seq_next_vcc(e, vcc);
876 	if (vcc && pos != NULL) {
877 		while (*pos) {
878 			vcc = clip_seq_next_vcc(e, vcc);
879 			if (!vcc)
880 				break;
881 			--(*pos);
882 		}
883 	}
884 	state->vcc = vcc;
885 
886 	return vcc;
887 }
888 
889 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
890 			       struct neighbour *n, loff_t * pos)
891 {
892 	struct clip_seq_state *state = (struct clip_seq_state *)_state;
893 
894 	return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
895 }
896 
897 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
898 {
899 	struct clip_seq_state *state = seq->private;
900 	state->ns.neigh_sub_iter = clip_seq_sub_iter;
901 	return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
902 }
903 
904 static int clip_seq_show(struct seq_file *seq, void *v)
905 {
906 	static char atm_arp_banner[] =
907 	    "IPitf TypeEncp Idle IP address      ATM address\n";
908 
909 	if (v == SEQ_START_TOKEN) {
910 		seq_puts(seq, atm_arp_banner);
911 	} else {
912 		struct clip_seq_state *state = seq->private;
913 		struct neighbour *n = v;
914 		struct clip_vcc *vcc = state->vcc;
915 
916 		atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
917 	}
918 	return 0;
919 }
920 
921 static const struct seq_operations arp_seq_ops = {
922 	.start	= clip_seq_start,
923 	.next	= neigh_seq_next,
924 	.stop	= neigh_seq_stop,
925 	.show	= clip_seq_show,
926 };
927 
928 static int arp_seq_open(struct inode *inode, struct file *file)
929 {
930 	return seq_open_net(inode, file, &arp_seq_ops,
931 			    sizeof(struct clip_seq_state));
932 }
933 
934 static const struct file_operations arp_seq_fops = {
935 	.open		= arp_seq_open,
936 	.read		= seq_read,
937 	.llseek		= seq_lseek,
938 	.release	= seq_release_net,
939 	.owner		= THIS_MODULE
940 };
941 #endif
942 
943 static void atm_clip_exit_noproc(void);
944 
945 static int __init atm_clip_init(void)
946 {
947 	neigh_table_init_no_netlink(&clip_tbl);
948 
949 	clip_tbl_hook = &clip_tbl;
950 	register_atm_ioctl(&clip_ioctl_ops);
951 	register_netdevice_notifier(&clip_dev_notifier);
952 	register_inetaddr_notifier(&clip_inet_notifier);
953 
954 	setup_timer(&idle_timer, idle_timer_check, 0);
955 
956 #ifdef CONFIG_PROC_FS
957 	{
958 		struct proc_dir_entry *p;
959 
960 		p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
961 		if (!p) {
962 			printk(KERN_ERR "Unable to initialize "
963 			       "/proc/net/atm/arp\n");
964 			atm_clip_exit_noproc();
965 			return -ENOMEM;
966 		}
967 	}
968 #endif
969 
970 	return 0;
971 }
972 
973 static void atm_clip_exit_noproc(void)
974 {
975 	struct net_device *dev, *next;
976 
977 	unregister_inetaddr_notifier(&clip_inet_notifier);
978 	unregister_netdevice_notifier(&clip_dev_notifier);
979 
980 	deregister_atm_ioctl(&clip_ioctl_ops);
981 
982 	/* First, stop the idle timer, so it stops banging
983 	 * on the table.
984 	 */
985 	del_timer_sync(&idle_timer);
986 
987 	/* Next, purge the table, so that the device
988 	 * unregister loop below does not hang due to
989 	 * device references remaining in the table.
990 	 */
991 	neigh_ifdown(&clip_tbl, NULL);
992 
993 	dev = clip_devs;
994 	while (dev) {
995 		next = PRIV(dev)->next;
996 		unregister_netdev(dev);
997 		free_netdev(dev);
998 		dev = next;
999 	}
1000 
1001 	/* Now it is safe to fully shutdown whole table. */
1002 	neigh_table_clear(&clip_tbl);
1003 
1004 	clip_tbl_hook = NULL;
1005 }
1006 
1007 static void __exit atm_clip_exit(void)
1008 {
1009 	remove_proc_entry("arp", atm_proc_root);
1010 
1011 	atm_clip_exit_noproc();
1012 }
1013 
1014 module_init(atm_clip_init);
1015 module_exit(atm_clip_exit);
1016 MODULE_AUTHOR("Werner Almesberger");
1017 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1018 MODULE_LICENSE("GPL");
1019