xref: /linux/net/atm/clip.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 
44 #if 0
45 #define DPRINTK(format,args...) printk(format,##args)
46 #else
47 #define DPRINTK(format,args...)
48 #endif
49 
50 
51 static struct net_device *clip_devs;
52 static struct atm_vcc *atmarpd;
53 static struct neigh_table clip_tbl;
54 static struct timer_list idle_timer;
55 
56 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
57 {
58 	struct sock *sk;
59 	struct atmarp_ctrl *ctrl;
60 	struct sk_buff *skb;
61 
62 	DPRINTK("to_atmarpd(%d)\n", type);
63 	if (!atmarpd)
64 		return -EUNATCH;
65 	skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
66 	if (!skb)
67 		return -ENOMEM;
68 	ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
69 	ctrl->type = type;
70 	ctrl->itf_num = itf;
71 	ctrl->ip = ip;
72 	atm_force_charge(atmarpd, skb->truesize);
73 
74 	sk = sk_atm(atmarpd);
75 	skb_queue_tail(&sk->sk_receive_queue, skb);
76 	sk->sk_data_ready(sk, skb->len);
77 	return 0;
78 }
79 
80 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
81 {
82 	DPRINTK("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
83 		entry->neigh);
84 	clip_vcc->entry = entry;
85 	clip_vcc->xoff = 0;	/* @@@ may overrun buffer by one packet */
86 	clip_vcc->next = entry->vccs;
87 	entry->vccs = clip_vcc;
88 	entry->neigh->used = jiffies;
89 }
90 
91 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
92 {
93 	struct atmarp_entry *entry = clip_vcc->entry;
94 	struct clip_vcc **walk;
95 
96 	if (!entry) {
97 		printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
98 		return;
99 	}
100 	netif_tx_lock_bh(entry->neigh->dev);	/* block clip_start_xmit() */
101 	entry->neigh->used = jiffies;
102 	for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
103 		if (*walk == clip_vcc) {
104 			int error;
105 
106 			*walk = clip_vcc->next;	/* atomic */
107 			clip_vcc->entry = NULL;
108 			if (clip_vcc->xoff)
109 				netif_wake_queue(entry->neigh->dev);
110 			if (entry->vccs)
111 				goto out;
112 			entry->expires = jiffies - 1;
113 			/* force resolution or expiration */
114 			error = neigh_update(entry->neigh, NULL, NUD_NONE,
115 					     NEIGH_UPDATE_F_ADMIN);
116 			if (error)
117 				printk(KERN_CRIT "unlink_clip_vcc: "
118 				       "neigh_update failed with %d\n", error);
119 			goto out;
120 		}
121 	printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
122 	       "0x%p)\n", entry, clip_vcc);
123       out:
124 	netif_tx_unlock_bh(entry->neigh->dev);
125 }
126 
127 /* The neighbour entry n->lock is held. */
128 static int neigh_check_cb(struct neighbour *n)
129 {
130 	struct atmarp_entry *entry = NEIGH2ENTRY(n);
131 	struct clip_vcc *cv;
132 
133 	for (cv = entry->vccs; cv; cv = cv->next) {
134 		unsigned long exp = cv->last_use + cv->idle_timeout;
135 
136 		if (cv->idle_timeout && time_after(jiffies, exp)) {
137 			DPRINTK("releasing vcc %p->%p of entry %p\n",
138 				cv, cv->vcc, entry);
139 			vcc_release_async(cv->vcc, -ETIMEDOUT);
140 		}
141 	}
142 
143 	if (entry->vccs || time_before(jiffies, entry->expires))
144 		return 0;
145 
146 	if (atomic_read(&n->refcnt) > 1) {
147 		struct sk_buff *skb;
148 
149 		DPRINTK("destruction postponed with ref %d\n",
150 			atomic_read(&n->refcnt));
151 
152 		while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
153 			dev_kfree_skb(skb);
154 
155 		return 0;
156 	}
157 
158 	DPRINTK("expired neigh %p\n", n);
159 	return 1;
160 }
161 
162 static void idle_timer_check(unsigned long dummy)
163 {
164 	write_lock(&clip_tbl.lock);
165 	__neigh_for_each_release(&clip_tbl, neigh_check_cb);
166 	mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
167 	write_unlock(&clip_tbl.lock);
168 }
169 
170 static int clip_arp_rcv(struct sk_buff *skb)
171 {
172 	struct atm_vcc *vcc;
173 
174 	DPRINTK("clip_arp_rcv\n");
175 	vcc = ATM_SKB(skb)->vcc;
176 	if (!vcc || !atm_charge(vcc, skb->truesize)) {
177 		dev_kfree_skb_any(skb);
178 		return 0;
179 	}
180 	DPRINTK("pushing to %p\n", vcc);
181 	DPRINTK("using %p\n", CLIP_VCC(vcc)->old_push);
182 	CLIP_VCC(vcc)->old_push(vcc, skb);
183 	return 0;
184 }
185 
186 static const unsigned char llc_oui[] = {
187 	0xaa,	/* DSAP: non-ISO */
188 	0xaa,	/* SSAP: non-ISO */
189 	0x03,	/* Ctrl: Unnumbered Information Command PDU */
190 	0x00,	/* OUI: EtherType */
191 	0x00,
192 	0x00
193 };
194 
195 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
196 {
197 	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
198 
199 	DPRINTK("clip push\n");
200 	if (!skb) {
201 		DPRINTK("removing VCC %p\n", clip_vcc);
202 		if (clip_vcc->entry)
203 			unlink_clip_vcc(clip_vcc);
204 		clip_vcc->old_push(vcc, NULL);	/* pass on the bad news */
205 		kfree(clip_vcc);
206 		return;
207 	}
208 	atm_return(vcc, skb->truesize);
209 	skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
210 	/* clip_vcc->entry == NULL if we don't have an IP address yet */
211 	if (!skb->dev) {
212 		dev_kfree_skb_any(skb);
213 		return;
214 	}
215 	ATM_SKB(skb)->vcc = vcc;
216 	skb->mac.raw = skb->data;
217 	if (!clip_vcc->encap
218 	    || skb->len < RFC1483LLC_LEN
219 	    || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
220 		skb->protocol = htons(ETH_P_IP);
221 	else {
222 		skb->protocol = ((__be16 *) skb->data)[3];
223 		skb_pull(skb, RFC1483LLC_LEN);
224 		if (skb->protocol == htons(ETH_P_ARP)) {
225 			PRIV(skb->dev)->stats.rx_packets++;
226 			PRIV(skb->dev)->stats.rx_bytes += skb->len;
227 			clip_arp_rcv(skb);
228 			return;
229 		}
230 	}
231 	clip_vcc->last_use = jiffies;
232 	PRIV(skb->dev)->stats.rx_packets++;
233 	PRIV(skb->dev)->stats.rx_bytes += skb->len;
234 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
235 	netif_rx(skb);
236 }
237 
238 /*
239  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
240  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
241  */
242 
243 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
244 {
245 	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
246 	struct net_device *dev = skb->dev;
247 	int old;
248 	unsigned long flags;
249 
250 	DPRINTK("clip_pop(vcc %p)\n", vcc);
251 	clip_vcc->old_pop(vcc, skb);
252 	/* skb->dev == NULL in outbound ARP packets */
253 	if (!dev)
254 		return;
255 	spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
256 	if (atm_may_send(vcc, 0)) {
257 		old = xchg(&clip_vcc->xoff, 0);
258 		if (old)
259 			netif_wake_queue(dev);
260 	}
261 	spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
262 }
263 
264 static void clip_neigh_destroy(struct neighbour *neigh)
265 {
266 	DPRINTK("clip_neigh_destroy (neigh %p)\n", neigh);
267 	if (NEIGH2ENTRY(neigh)->vccs)
268 		printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
269 	NEIGH2ENTRY(neigh)->vccs = (void *) NEIGHBOR_DEAD;
270 }
271 
272 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
273 {
274 	DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
275 	to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
276 }
277 
278 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
279 {
280 #ifndef CONFIG_ATM_CLIP_NO_ICMP
281 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
282 #endif
283 	kfree_skb(skb);
284 }
285 
286 static struct neigh_ops clip_neigh_ops = {
287 	.family =		AF_INET,
288 	.solicit =		clip_neigh_solicit,
289 	.error_report =		clip_neigh_error,
290 	.output =		dev_queue_xmit,
291 	.connected_output =	dev_queue_xmit,
292 	.hh_output =		dev_queue_xmit,
293 	.queue_xmit =		dev_queue_xmit,
294 };
295 
296 static int clip_constructor(struct neighbour *neigh)
297 {
298 	struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
299 	struct net_device *dev = neigh->dev;
300 	struct in_device *in_dev;
301 	struct neigh_parms *parms;
302 
303 	DPRINTK("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
304 	neigh->type = inet_addr_type(entry->ip);
305 	if (neigh->type != RTN_UNICAST)
306 		return -EINVAL;
307 
308 	rcu_read_lock();
309 	in_dev = __in_dev_get_rcu(dev);
310 	if (!in_dev) {
311 		rcu_read_unlock();
312 		return -EINVAL;
313 	}
314 
315 	parms = in_dev->arp_parms;
316 	__neigh_parms_put(neigh->parms);
317 	neigh->parms = neigh_parms_clone(parms);
318 	rcu_read_unlock();
319 
320 	neigh->ops = &clip_neigh_ops;
321 	neigh->output = neigh->nud_state & NUD_VALID ?
322 	    neigh->ops->connected_output : neigh->ops->output;
323 	entry->neigh = neigh;
324 	entry->vccs = NULL;
325 	entry->expires = jiffies - 1;
326 	return 0;
327 }
328 
329 static u32 clip_hash(const void *pkey, const struct net_device *dev)
330 {
331 	return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
332 }
333 
334 static struct neigh_table clip_tbl = {
335 	.family 	= AF_INET,
336 	.entry_size 	= sizeof(struct neighbour)+sizeof(struct atmarp_entry),
337 	.key_len 	= 4,
338 	.hash 		= clip_hash,
339 	.constructor 	= clip_constructor,
340 	.id 		= "clip_arp_cache",
341 
342 	/* parameters are copied from ARP ... */
343 	.parms = {
344 		.tbl 			= &clip_tbl,
345 		.neigh_destructor	= clip_neigh_destroy,
346 		.base_reachable_time 	= 30 * HZ,
347 		.retrans_time 		= 1 * HZ,
348 		.gc_staletime 		= 60 * HZ,
349 		.reachable_time 	= 30 * HZ,
350 		.delay_probe_time 	= 5 * HZ,
351 		.queue_len 		= 3,
352 		.ucast_probes 		= 3,
353 		.mcast_probes 		= 3,
354 		.anycast_delay 		= 1 * HZ,
355 		.proxy_delay 		= (8 * HZ) / 10,
356 		.proxy_qlen 		= 64,
357 		.locktime 		= 1 * HZ,
358 	},
359 	.gc_interval 	= 30 * HZ,
360 	.gc_thresh1 	= 128,
361 	.gc_thresh2 	= 512,
362 	.gc_thresh3 	= 1024,
363 };
364 
365 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
366 
367 /*
368  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
369  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
370  * don't increment the usage count. This is used to create entries in
371  * clip_setentry.
372  */
373 
374 static int clip_encap(struct atm_vcc *vcc, int mode)
375 {
376 	CLIP_VCC(vcc)->encap = mode;
377 	return 0;
378 }
379 
380 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
381 {
382 	struct clip_priv *clip_priv = PRIV(dev);
383 	struct atmarp_entry *entry;
384 	struct atm_vcc *vcc;
385 	int old;
386 	unsigned long flags;
387 
388 	DPRINTK("clip_start_xmit (skb %p)\n", skb);
389 	if (!skb->dst) {
390 		printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
391 		dev_kfree_skb(skb);
392 		clip_priv->stats.tx_dropped++;
393 		return 0;
394 	}
395 	if (!skb->dst->neighbour) {
396 #if 0
397 		skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
398 		if (!skb->dst->neighbour) {
399 			dev_kfree_skb(skb);	/* lost that one */
400 			clip_priv->stats.tx_dropped++;
401 			return 0;
402 		}
403 #endif
404 		printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
405 		dev_kfree_skb(skb);
406 		clip_priv->stats.tx_dropped++;
407 		return 0;
408 	}
409 	entry = NEIGH2ENTRY(skb->dst->neighbour);
410 	if (!entry->vccs) {
411 		if (time_after(jiffies, entry->expires)) {
412 			/* should be resolved */
413 			entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
414 			to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
415 		}
416 		if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
417 			skb_queue_tail(&entry->neigh->arp_queue, skb);
418 		else {
419 			dev_kfree_skb(skb);
420 			clip_priv->stats.tx_dropped++;
421 		}
422 		return 0;
423 	}
424 	DPRINTK("neigh %p, vccs %p\n", entry, entry->vccs);
425 	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
426 	DPRINTK("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
427 	if (entry->vccs->encap) {
428 		void *here;
429 
430 		here = skb_push(skb, RFC1483LLC_LEN);
431 		memcpy(here, llc_oui, sizeof(llc_oui));
432 		((__be16 *) here)[3] = skb->protocol;
433 	}
434 	atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
435 	ATM_SKB(skb)->atm_options = vcc->atm_options;
436 	entry->vccs->last_use = jiffies;
437 	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
438 	old = xchg(&entry->vccs->xoff, 1);	/* assume XOFF ... */
439 	if (old) {
440 		printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
441 		return 0;
442 	}
443 	clip_priv->stats.tx_packets++;
444 	clip_priv->stats.tx_bytes += skb->len;
445 	vcc->send(vcc, skb);
446 	if (atm_may_send(vcc, 0)) {
447 		entry->vccs->xoff = 0;
448 		return 0;
449 	}
450 	spin_lock_irqsave(&clip_priv->xoff_lock, flags);
451 	netif_stop_queue(dev);	/* XOFF -> throttle immediately */
452 	barrier();
453 	if (!entry->vccs->xoff)
454 		netif_start_queue(dev);
455 	/* Oh, we just raced with clip_pop. netif_start_queue should be
456 	   good enough, because nothing should really be asleep because
457 	   of the brief netif_stop_queue. If this isn't true or if it
458 	   changes, use netif_wake_queue instead. */
459 	spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
460 	return 0;
461 }
462 
463 static struct net_device_stats *clip_get_stats(struct net_device *dev)
464 {
465 	return &PRIV(dev)->stats;
466 }
467 
468 static int clip_mkip(struct atm_vcc *vcc, int timeout)
469 {
470 	struct clip_vcc *clip_vcc;
471 	struct sk_buff *skb;
472 	struct sk_buff_head *rq;
473 	unsigned long flags;
474 
475 	if (!vcc->push)
476 		return -EBADFD;
477 	clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
478 	if (!clip_vcc)
479 		return -ENOMEM;
480 	DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
481 	clip_vcc->vcc = vcc;
482 	vcc->user_back = clip_vcc;
483 	set_bit(ATM_VF_IS_CLIP, &vcc->flags);
484 	clip_vcc->entry = NULL;
485 	clip_vcc->xoff = 0;
486 	clip_vcc->encap = 1;
487 	clip_vcc->last_use = jiffies;
488 	clip_vcc->idle_timeout = timeout * HZ;
489 	clip_vcc->old_push = vcc->push;
490 	clip_vcc->old_pop = vcc->pop;
491 	vcc->push = clip_push;
492 	vcc->pop = clip_pop;
493 
494 	rq = &sk_atm(vcc)->sk_receive_queue;
495 
496 	spin_lock_irqsave(&rq->lock, flags);
497 	if (skb_queue_empty(rq)) {
498 		skb = NULL;
499 	} else {
500 		/* NULL terminate the list.  */
501 		rq->prev->next = NULL;
502 		skb = rq->next;
503 	}
504 	rq->prev = rq->next = (struct sk_buff *)rq;
505 	rq->qlen = 0;
506 	spin_unlock_irqrestore(&rq->lock, flags);
507 
508 	/* re-process everything received between connection setup and MKIP */
509 	while (skb) {
510 		struct sk_buff *next = skb->next;
511 
512 		skb->next = skb->prev = NULL;
513 		if (!clip_devs) {
514 			atm_return(vcc, skb->truesize);
515 			kfree_skb(skb);
516 		} else {
517 			unsigned int len = skb->len;
518 
519 			skb_get(skb);
520 			clip_push(vcc, skb);
521 			PRIV(skb->dev)->stats.rx_packets--;
522 			PRIV(skb->dev)->stats.rx_bytes -= len;
523 			kfree_skb(skb);
524 		}
525 
526 		skb = next;
527 	}
528 	return 0;
529 }
530 
531 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
532 {
533 	struct neighbour *neigh;
534 	struct atmarp_entry *entry;
535 	int error;
536 	struct clip_vcc *clip_vcc;
537 	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
538 	struct rtable *rt;
539 
540 	if (vcc->push != clip_push) {
541 		printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
542 		return -EBADF;
543 	}
544 	clip_vcc = CLIP_VCC(vcc);
545 	if (!ip) {
546 		if (!clip_vcc->entry) {
547 			printk(KERN_ERR "hiding hidden ATMARP entry\n");
548 			return 0;
549 		}
550 		DPRINTK("setentry: remove\n");
551 		unlink_clip_vcc(clip_vcc);
552 		return 0;
553 	}
554 	error = ip_route_output_key(&rt, &fl);
555 	if (error)
556 		return error;
557 	neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
558 	ip_rt_put(rt);
559 	if (!neigh)
560 		return -ENOMEM;
561 	entry = NEIGH2ENTRY(neigh);
562 	if (entry != clip_vcc->entry) {
563 		if (!clip_vcc->entry)
564 			DPRINTK("setentry: add\n");
565 		else {
566 			DPRINTK("setentry: update\n");
567 			unlink_clip_vcc(clip_vcc);
568 		}
569 		link_vcc(clip_vcc, entry);
570 	}
571 	error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
572 			     NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
573 	neigh_release(neigh);
574 	return error;
575 }
576 
577 static void clip_setup(struct net_device *dev)
578 {
579 	dev->hard_start_xmit = clip_start_xmit;
580 	/* sg_xmit ... */
581 	dev->get_stats = clip_get_stats;
582 	dev->type = ARPHRD_ATM;
583 	dev->hard_header_len = RFC1483LLC_LEN;
584 	dev->mtu = RFC1626_MTU;
585 	dev->tx_queue_len = 100;	/* "normal" queue (packets) */
586 	/* When using a "real" qdisc, the qdisc determines the queue */
587 	/* length. tx_queue_len is only used for the default case, */
588 	/* without any more elaborate queuing. 100 is a reasonable */
589 	/* compromise between decent burst-tolerance and protection */
590 	/* against memory hogs. */
591 }
592 
593 static int clip_create(int number)
594 {
595 	struct net_device *dev;
596 	struct clip_priv *clip_priv;
597 	int error;
598 
599 	if (number != -1) {
600 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
601 			if (PRIV(dev)->number == number)
602 				return -EEXIST;
603 	} else {
604 		number = 0;
605 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
606 			if (PRIV(dev)->number >= number)
607 				number = PRIV(dev)->number + 1;
608 	}
609 	dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
610 	if (!dev)
611 		return -ENOMEM;
612 	clip_priv = PRIV(dev);
613 	sprintf(dev->name, "atm%d", number);
614 	spin_lock_init(&clip_priv->xoff_lock);
615 	clip_priv->number = number;
616 	error = register_netdev(dev);
617 	if (error) {
618 		free_netdev(dev);
619 		return error;
620 	}
621 	clip_priv->next = clip_devs;
622 	clip_devs = dev;
623 	DPRINTK("registered (net:%s)\n", dev->name);
624 	return number;
625 }
626 
627 static int clip_device_event(struct notifier_block *this, unsigned long event,
628 			     void *arg)
629 {
630 	struct net_device *dev = arg;
631 
632 	if (event == NETDEV_UNREGISTER) {
633 		neigh_ifdown(&clip_tbl, dev);
634 		return NOTIFY_DONE;
635 	}
636 
637 	/* ignore non-CLIP devices */
638 	if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
639 		return NOTIFY_DONE;
640 
641 	switch (event) {
642 	case NETDEV_UP:
643 		DPRINTK("clip_device_event NETDEV_UP\n");
644 		to_atmarpd(act_up, PRIV(dev)->number, 0);
645 		break;
646 	case NETDEV_GOING_DOWN:
647 		DPRINTK("clip_device_event NETDEV_DOWN\n");
648 		to_atmarpd(act_down, PRIV(dev)->number, 0);
649 		break;
650 	case NETDEV_CHANGE:
651 	case NETDEV_CHANGEMTU:
652 		DPRINTK("clip_device_event NETDEV_CHANGE*\n");
653 		to_atmarpd(act_change, PRIV(dev)->number, 0);
654 		break;
655 	}
656 	return NOTIFY_DONE;
657 }
658 
659 static int clip_inet_event(struct notifier_block *this, unsigned long event,
660 			   void *ifa)
661 {
662 	struct in_device *in_dev;
663 
664 	in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
665 	if (!in_dev || !in_dev->dev) {
666 		printk(KERN_WARNING "clip_inet_event: no device\n");
667 		return NOTIFY_DONE;
668 	}
669 	/*
670 	 * Transitions are of the down-change-up type, so it's sufficient to
671 	 * handle the change on up.
672 	 */
673 	if (event != NETDEV_UP)
674 		return NOTIFY_DONE;
675 	return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
676 }
677 
678 
679 static struct notifier_block clip_dev_notifier = {
680 	.notifier_call = clip_device_event,
681 };
682 
683 
684 
685 static struct notifier_block clip_inet_notifier = {
686 	.notifier_call = clip_inet_event,
687 };
688 
689 
690 
691 static void atmarpd_close(struct atm_vcc *vcc)
692 {
693 	DPRINTK("atmarpd_close\n");
694 
695 	rtnl_lock();
696 	atmarpd = NULL;
697 	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
698 	rtnl_unlock();
699 
700 	DPRINTK("(done)\n");
701 	module_put(THIS_MODULE);
702 }
703 
704 
705 static struct atmdev_ops atmarpd_dev_ops = {
706 	.close = atmarpd_close
707 };
708 
709 
710 static struct atm_dev atmarpd_dev = {
711 	.ops =			&atmarpd_dev_ops,
712 	.type =			"arpd",
713 	.number = 		999,
714 	.lock =			SPIN_LOCK_UNLOCKED
715 };
716 
717 
718 static int atm_init_atmarp(struct atm_vcc *vcc)
719 {
720 	rtnl_lock();
721 	if (atmarpd) {
722 		rtnl_unlock();
723 		return -EADDRINUSE;
724 	}
725 
726 	mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
727 
728 	atmarpd = vcc;
729 	set_bit(ATM_VF_META,&vcc->flags);
730 	set_bit(ATM_VF_READY,&vcc->flags);
731 	    /* allow replies and avoid getting closed if signaling dies */
732 	vcc->dev = &atmarpd_dev;
733 	vcc_insert_socket(sk_atm(vcc));
734 	vcc->push = NULL;
735 	vcc->pop = NULL; /* crash */
736 	vcc->push_oam = NULL; /* crash */
737 	rtnl_unlock();
738 	return 0;
739 }
740 
741 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
742 {
743 	struct atm_vcc *vcc = ATM_SD(sock);
744 	int err = 0;
745 
746 	switch (cmd) {
747 	case SIOCMKCLIP:
748 	case ATMARPD_CTRL:
749 	case ATMARP_MKIP:
750 	case ATMARP_SETENTRY:
751 	case ATMARP_ENCAP:
752 		if (!capable(CAP_NET_ADMIN))
753 			return -EPERM;
754 		break;
755 	default:
756 		return -ENOIOCTLCMD;
757 	}
758 
759 	switch (cmd) {
760 	case SIOCMKCLIP:
761 		err = clip_create(arg);
762 		break;
763 	case ATMARPD_CTRL:
764 		err = atm_init_atmarp(vcc);
765 		if (!err) {
766 			sock->state = SS_CONNECTED;
767 			__module_get(THIS_MODULE);
768 		}
769 		break;
770 	case ATMARP_MKIP:
771 		err = clip_mkip(vcc, arg);
772 		break;
773 	case ATMARP_SETENTRY:
774 		err = clip_setentry(vcc, (__force __be32)arg);
775 		break;
776 	case ATMARP_ENCAP:
777 		err = clip_encap(vcc, arg);
778 		break;
779 	}
780 	return err;
781 }
782 
783 static struct atm_ioctl clip_ioctl_ops = {
784 	.owner = THIS_MODULE,
785 	.ioctl = clip_ioctl,
786 };
787 
788 #ifdef CONFIG_PROC_FS
789 
790 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
791 {
792 	static int code[] = { 1, 2, 10, 6, 1, 0 };
793 	static int e164[] = { 1, 8, 4, 6, 1, 0 };
794 
795 	if (*addr->sas_addr.pub) {
796 		seq_printf(seq, "%s", addr->sas_addr.pub);
797 		if (*addr->sas_addr.prv)
798 			seq_putc(seq, '+');
799 	} else if (!*addr->sas_addr.prv) {
800 		seq_printf(seq, "%s", "(none)");
801 		return;
802 	}
803 	if (*addr->sas_addr.prv) {
804 		unsigned char *prv = addr->sas_addr.prv;
805 		int *fields;
806 		int i, j;
807 
808 		fields = *prv == ATM_AFI_E164 ? e164 : code;
809 		for (i = 0; fields[i]; i++) {
810 			for (j = fields[i]; j; j--)
811 				seq_printf(seq, "%02X", *prv++);
812 			if (fields[i + 1])
813 				seq_putc(seq, '.');
814 		}
815 	}
816 }
817 
818 /* This means the neighbour entry has no attached VCC objects. */
819 #define SEQ_NO_VCC_TOKEN	((void *) 2)
820 
821 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
822 			struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
823 {
824 	unsigned long exp;
825 	char buf[17];
826 	int svc, llc, off;
827 
828 	svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
829 	       (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
830 
831 	llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
832 
833 	if (clip_vcc == SEQ_NO_VCC_TOKEN)
834 		exp = entry->neigh->used;
835 	else
836 		exp = clip_vcc->last_use;
837 
838 	exp = (jiffies - exp) / HZ;
839 
840 	seq_printf(seq, "%-6s%-4s%-4s%5ld ",
841 		   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
842 
843 	off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
844 			NIPQUAD(entry->ip));
845 	while (off < 16)
846 		buf[off++] = ' ';
847 	buf[off] = '\0';
848 	seq_printf(seq, "%s", buf);
849 
850 	if (clip_vcc == SEQ_NO_VCC_TOKEN) {
851 		if (time_before(jiffies, entry->expires))
852 			seq_printf(seq, "(resolving)\n");
853 		else
854 			seq_printf(seq, "(expired, ref %d)\n",
855 				   atomic_read(&entry->neigh->refcnt));
856 	} else if (!svc) {
857 		seq_printf(seq, "%d.%d.%d\n",
858 			   clip_vcc->vcc->dev->number,
859 			   clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
860 	} else {
861 		svc_addr(seq, &clip_vcc->vcc->remote);
862 		seq_putc(seq, '\n');
863 	}
864 }
865 
866 struct clip_seq_state {
867 	/* This member must be first. */
868 	struct neigh_seq_state ns;
869 
870 	/* Local to clip specific iteration. */
871 	struct clip_vcc *vcc;
872 };
873 
874 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
875 					  struct clip_vcc *curr)
876 {
877 	if (!curr) {
878 		curr = e->vccs;
879 		if (!curr)
880 			return SEQ_NO_VCC_TOKEN;
881 		return curr;
882 	}
883 	if (curr == SEQ_NO_VCC_TOKEN)
884 		return NULL;
885 
886 	curr = curr->next;
887 
888 	return curr;
889 }
890 
891 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
892 			       struct atmarp_entry *e, loff_t * pos)
893 {
894 	struct clip_vcc *vcc = state->vcc;
895 
896 	vcc = clip_seq_next_vcc(e, vcc);
897 	if (vcc && pos != NULL) {
898 		while (*pos) {
899 			vcc = clip_seq_next_vcc(e, vcc);
900 			if (!vcc)
901 				break;
902 			--(*pos);
903 		}
904 	}
905 	state->vcc = vcc;
906 
907 	return vcc;
908 }
909 
910 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
911 			       struct neighbour *n, loff_t * pos)
912 {
913 	struct clip_seq_state *state = (struct clip_seq_state *)_state;
914 
915 	return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
916 }
917 
918 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
919 {
920 	return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
921 }
922 
923 static int clip_seq_show(struct seq_file *seq, void *v)
924 {
925 	static char atm_arp_banner[] =
926 	    "IPitf TypeEncp Idle IP address      ATM address\n";
927 
928 	if (v == SEQ_START_TOKEN) {
929 		seq_puts(seq, atm_arp_banner);
930 	} else {
931 		struct clip_seq_state *state = seq->private;
932 		struct neighbour *n = v;
933 		struct clip_vcc *vcc = state->vcc;
934 
935 		atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
936 	}
937 	return 0;
938 }
939 
940 static struct seq_operations arp_seq_ops = {
941 	.start	= clip_seq_start,
942 	.next	= neigh_seq_next,
943 	.stop	= neigh_seq_stop,
944 	.show	= clip_seq_show,
945 };
946 
947 static int arp_seq_open(struct inode *inode, struct file *file)
948 {
949 	struct clip_seq_state *state;
950 	struct seq_file *seq;
951 	int rc = -EAGAIN;
952 
953 	state = kzalloc(sizeof(*state), GFP_KERNEL);
954 	if (!state) {
955 		rc = -ENOMEM;
956 		goto out_kfree;
957 	}
958 	state->ns.neigh_sub_iter = clip_seq_sub_iter;
959 
960 	rc = seq_open(file, &arp_seq_ops);
961 	if (rc)
962 		goto out_kfree;
963 
964 	seq = file->private_data;
965 	seq->private = state;
966 out:
967 	return rc;
968 
969 out_kfree:
970 	kfree(state);
971 	goto out;
972 }
973 
974 static const struct file_operations arp_seq_fops = {
975 	.open		= arp_seq_open,
976 	.read		= seq_read,
977 	.llseek		= seq_lseek,
978 	.release	= seq_release_private,
979 	.owner		= THIS_MODULE
980 };
981 #endif
982 
983 static int __init atm_clip_init(void)
984 {
985 	neigh_table_init_no_netlink(&clip_tbl);
986 
987 	clip_tbl_hook = &clip_tbl;
988 	register_atm_ioctl(&clip_ioctl_ops);
989 	register_netdevice_notifier(&clip_dev_notifier);
990 	register_inetaddr_notifier(&clip_inet_notifier);
991 
992 	setup_timer(&idle_timer, idle_timer_check, 0);
993 
994 #ifdef CONFIG_PROC_FS
995 	{
996 		struct proc_dir_entry *p;
997 
998 		p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
999 		if (p)
1000 			p->proc_fops = &arp_seq_fops;
1001 	}
1002 #endif
1003 
1004 	return 0;
1005 }
1006 
1007 static void __exit atm_clip_exit(void)
1008 {
1009 	struct net_device *dev, *next;
1010 
1011 	remove_proc_entry("arp", atm_proc_root);
1012 
1013 	unregister_inetaddr_notifier(&clip_inet_notifier);
1014 	unregister_netdevice_notifier(&clip_dev_notifier);
1015 
1016 	deregister_atm_ioctl(&clip_ioctl_ops);
1017 
1018 	/* First, stop the idle timer, so it stops banging
1019 	 * on the table.
1020 	 */
1021 	del_timer_sync(&idle_timer);
1022 
1023 	/* Next, purge the table, so that the device
1024 	 * unregister loop below does not hang due to
1025 	 * device references remaining in the table.
1026 	 */
1027 	neigh_ifdown(&clip_tbl, NULL);
1028 
1029 	dev = clip_devs;
1030 	while (dev) {
1031 		next = PRIV(dev)->next;
1032 		unregister_netdev(dev);
1033 		free_netdev(dev);
1034 		dev = next;
1035 	}
1036 
1037 	/* Now it is safe to fully shutdown whole table. */
1038 	neigh_table_clear(&clip_tbl);
1039 
1040 	clip_tbl_hook = NULL;
1041 }
1042 
1043 module_init(atm_clip_init);
1044 module_exit(atm_clip_exit);
1045 MODULE_AUTHOR("Werner Almesberger");
1046 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1047 MODULE_LICENSE("GPL");
1048