xref: /openbmc/linux/net/atm/clip.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /* net/atm/clip.c - RFC1577 Classical IP over ATM */
2 
3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4 
5 
6 #include <linux/config.h>
7 #include <linux/string.h>
8 #include <linux/errno.h>
9 #include <linux/kernel.h> /* for UINT_MAX */
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/netdevice.h>
13 #include <linux/skbuff.h>
14 #include <linux/wait.h>
15 #include <linux/timer.h>
16 #include <linux/if_arp.h> /* for some manifest constants */
17 #include <linux/notifier.h>
18 #include <linux/atm.h>
19 #include <linux/atmdev.h>
20 #include <linux/atmclip.h>
21 #include <linux/atmarp.h>
22 #include <linux/ip.h> /* for net/route.h */
23 #include <linux/in.h> /* for struct sockaddr_in */
24 #include <linux/if.h> /* for IFF_UP */
25 #include <linux/inetdevice.h>
26 #include <linux/bitops.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 "ipcommon.h"
42 #include <net/atmclip.h>
43 
44 
45 #if 0
46 #define DPRINTK(format,args...) printk(format,##args)
47 #else
48 #define DPRINTK(format,args...)
49 #endif
50 
51 
52 static struct net_device *clip_devs;
53 static struct atm_vcc *atmarpd;
54 static struct neigh_table clip_tbl;
55 static struct timer_list idle_timer;
56 static int start_timer = 1;
57 
58 
59 static int to_atmarpd(enum atmarp_ctrl_type type,int itf,unsigned long ip)
60 {
61 	struct sock *sk;
62 	struct atmarp_ctrl *ctrl;
63 	struct sk_buff *skb;
64 
65 	DPRINTK("to_atmarpd(%d)\n",type);
66 	if (!atmarpd) return -EUNATCH;
67 	skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
68 	if (!skb) return -ENOMEM;
69 	ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
70 	ctrl->type = type;
71 	ctrl->itf_num = itf;
72 	ctrl->ip = ip;
73 	atm_force_charge(atmarpd,skb->truesize);
74 
75 	sk = sk_atm(atmarpd);
76 	skb_queue_tail(&sk->sk_receive_queue, skb);
77 	sk->sk_data_ready(sk, skb->len);
78 	return 0;
79 }
80 
81 
82 static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry)
83 {
84 	DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry,
85 	    entry->neigh);
86 	clip_vcc->entry = entry;
87 	clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */
88 	clip_vcc->next = entry->vccs;
89 	entry->vccs = clip_vcc;
90 	entry->neigh->used = jiffies;
91 }
92 
93 
94 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
95 {
96 	struct atmarp_entry *entry = clip_vcc->entry;
97 	struct clip_vcc **walk;
98 
99 	if (!entry) {
100 		printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc);
101 		return;
102 	}
103 	spin_lock_bh(&entry->neigh->dev->xmit_lock);	/* block clip_start_xmit() */
104 	entry->neigh->used = jiffies;
105 	for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
106 		if (*walk == clip_vcc) {
107 			int error;
108 
109 			*walk = clip_vcc->next; /* atomic */
110 			clip_vcc->entry = NULL;
111 			if (clip_vcc->xoff)
112 				netif_wake_queue(entry->neigh->dev);
113 			if (entry->vccs)
114 				goto out;
115 			entry->expires = jiffies-1;
116 				/* force resolution or expiration */
117 			error = neigh_update(entry->neigh, NULL, NUD_NONE,
118 					     NEIGH_UPDATE_F_ADMIN);
119 			if (error)
120 				printk(KERN_CRIT "unlink_clip_vcc: "
121 				    "neigh_update failed with %d\n",error);
122 			goto out;
123 		}
124 	printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
125 	  "0x%p)\n",entry,clip_vcc);
126 out:
127 	spin_unlock_bh(&entry->neigh->dev->xmit_lock);
128 }
129 
130 /* The neighbour entry n->lock is held. */
131 static int neigh_check_cb(struct neighbour *n)
132 {
133 	struct atmarp_entry *entry = NEIGH2ENTRY(n);
134 	struct clip_vcc *cv;
135 
136 	for (cv = entry->vccs; cv; cv = cv->next) {
137 		unsigned long exp = cv->last_use + cv->idle_timeout;
138 
139 		if (cv->idle_timeout && time_after(jiffies, exp)) {
140 			DPRINTK("releasing vcc %p->%p of entry %p\n",
141 				cv, cv->vcc, entry);
142 			vcc_release_async(cv->vcc, -ETIMEDOUT);
143 		}
144 	}
145 
146 	if (entry->vccs || time_before(jiffies, entry->expires))
147 		return 0;
148 
149 	if (atomic_read(&n->refcnt) > 1) {
150 		struct sk_buff *skb;
151 
152 		DPRINTK("destruction postponed with ref %d\n",
153 			atomic_read(&n->refcnt));
154 
155 		while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
156 			dev_kfree_skb(skb);
157 
158 		return 0;
159 	}
160 
161 	DPRINTK("expired neigh %p\n",n);
162 	return 1;
163 }
164 
165 static void idle_timer_check(unsigned long dummy)
166 {
167 	write_lock(&clip_tbl.lock);
168 	__neigh_for_each_release(&clip_tbl, neigh_check_cb);
169 	mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
170 	write_unlock(&clip_tbl.lock);
171 }
172 
173 static int clip_arp_rcv(struct sk_buff *skb)
174 {
175 	struct atm_vcc *vcc;
176 
177 	DPRINTK("clip_arp_rcv\n");
178 	vcc = ATM_SKB(skb)->vcc;
179 	if (!vcc || !atm_charge(vcc,skb->truesize)) {
180 		dev_kfree_skb_any(skb);
181 		return 0;
182 	}
183 	DPRINTK("pushing to %p\n",vcc);
184 	DPRINTK("using %p\n",CLIP_VCC(vcc)->old_push);
185 	CLIP_VCC(vcc)->old_push(vcc,skb);
186 	return 0;
187 }
188 
189 static const unsigned char llc_oui[] = {
190 	0xaa,	/* DSAP: non-ISO */
191 	0xaa,	/* SSAP: non-ISO */
192 	0x03,	/* Ctrl: Unnumbered Information Command PDU */
193 	0x00,	/* OUI: EtherType */
194 	0x00,
195 	0x00 };
196 
197 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
198 {
199 	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
200 
201 	DPRINTK("clip push\n");
202 	if (!skb) {
203 		DPRINTK("removing VCC %p\n",clip_vcc);
204 		if (clip_vcc->entry) unlink_clip_vcc(clip_vcc);
205 		clip_vcc->old_push(vcc,NULL); /* pass on the bad news */
206 		kfree(clip_vcc);
207 		return;
208 	}
209 	atm_return(vcc,skb->truesize);
210 	skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
211 		/* clip_vcc->entry == NULL if we don't have an IP address yet */
212 	if (!skb->dev) {
213 		dev_kfree_skb_any(skb);
214 		return;
215 	}
216 	ATM_SKB(skb)->vcc = vcc;
217 	skb->mac.raw = skb->data;
218 	if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
219 	    llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP);
220 	else {
221 		skb->protocol = ((u16 *) skb->data)[3];
222 		skb_pull(skb,RFC1483LLC_LEN);
223 		if (skb->protocol == htons(ETH_P_ARP)) {
224 			PRIV(skb->dev)->stats.rx_packets++;
225 			PRIV(skb->dev)->stats.rx_bytes += skb->len;
226 			clip_arp_rcv(skb);
227 			return;
228 		}
229 	}
230 	clip_vcc->last_use = jiffies;
231 	PRIV(skb->dev)->stats.rx_packets++;
232 	PRIV(skb->dev)->stats.rx_bytes += skb->len;
233 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
234 	netif_rx(skb);
235 }
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 
244 static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb)
245 {
246 	struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
247 	struct net_device *dev = skb->dev;
248 	int old;
249 	unsigned long flags;
250 
251 	DPRINTK("clip_pop(vcc %p)\n",vcc);
252 	clip_vcc->old_pop(vcc,skb);
253 	/* skb->dev == NULL in outbound ARP packets */
254 	if (!dev) 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) netif_wake_queue(dev);
259 	}
260 	spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
261 }
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 *) 0xdeadbeef;
270 }
271 
272 
273 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
274 {
275 	DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
276 	to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
277 }
278 
279 
280 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
281 {
282 #ifndef CONFIG_ATM_CLIP_NO_ICMP
283 	icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
284 #endif
285 	kfree_skb(skb);
286 }
287 
288 
289 static struct neigh_ops clip_neigh_ops = {
290 	.family =		AF_INET,
291 	.destructor =		clip_neigh_destroy,
292 	.solicit =		clip_neigh_solicit,
293 	.error_report =		clip_neigh_error,
294 	.output =		dev_queue_xmit,
295 	.connected_output =	dev_queue_xmit,
296 	.hh_output =		dev_queue_xmit,
297 	.queue_xmit =		dev_queue_xmit,
298 };
299 
300 
301 static int clip_constructor(struct neighbour *neigh)
302 {
303 	struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
304 	struct net_device *dev = neigh->dev;
305 	struct in_device *in_dev;
306 	struct neigh_parms *parms;
307 
308 	DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry);
309 	neigh->type = inet_addr_type(entry->ip);
310 	if (neigh->type != RTN_UNICAST) return -EINVAL;
311 
312 	rcu_read_lock();
313 	in_dev = rcu_dereference(__in_dev_get(dev));
314 	if (!in_dev) {
315 		rcu_read_unlock();
316 		return -EINVAL;
317 	}
318 
319 	parms = in_dev->arp_parms;
320 	__neigh_parms_put(neigh->parms);
321 	neigh->parms = neigh_parms_clone(parms);
322 	rcu_read_unlock();
323 
324 	neigh->ops = &clip_neigh_ops;
325 	neigh->output = neigh->nud_state & NUD_VALID ?
326 	    neigh->ops->connected_output : neigh->ops->output;
327 	entry->neigh = neigh;
328 	entry->vccs = NULL;
329 	entry->expires = jiffies-1;
330 	return 0;
331 }
332 
333 static u32 clip_hash(const void *pkey, const struct net_device *dev)
334 {
335 	return jhash_2words(*(u32 *)pkey, dev->ifindex, clip_tbl.hash_rnd);
336 }
337 
338 static struct neigh_table clip_tbl = {
339 	.family 	= AF_INET,
340 	.entry_size 	= sizeof(struct neighbour)+sizeof(struct atmarp_entry),
341 	.key_len 	= 4,
342 	.hash 		= clip_hash,
343 	.constructor 	= clip_constructor,
344 	.id 		= "clip_arp_cache",
345 
346 	/* parameters are copied from ARP ... */
347 	.parms = {
348 		.tbl 			= &clip_tbl,
349 		.base_reachable_time 	= 30 * HZ,
350 		.retrans_time 		= 1 * HZ,
351 		.gc_staletime 		= 60 * HZ,
352 		.reachable_time 	= 30 * HZ,
353 		.delay_probe_time 	= 5 * HZ,
354 		.queue_len 		= 3,
355 		.ucast_probes 		= 3,
356 		.mcast_probes 		= 3,
357 		.anycast_delay 		= 1 * HZ,
358 		.proxy_delay 		= (8 * HZ) / 10,
359 		.proxy_qlen 		= 64,
360 		.locktime 		= 1 * HZ,
361 	},
362 	.gc_interval 	= 30 * HZ,
363 	.gc_thresh1 	= 128,
364 	.gc_thresh2 	= 512,
365 	.gc_thresh3 	= 1024,
366 };
367 
368 
369 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
370 
371 /*
372  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
373  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
374  * don't increment the usage count. This is used to create entries in
375  * clip_setentry.
376  */
377 
378 
379 static int clip_encap(struct atm_vcc *vcc,int mode)
380 {
381 	CLIP_VCC(vcc)->encap = mode;
382 	return 0;
383 }
384 
385 
386 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
387 {
388 	struct clip_priv *clip_priv = PRIV(dev);
389 	struct atmarp_entry *entry;
390 	struct atm_vcc *vcc;
391 	int old;
392 	unsigned long flags;
393 
394 	DPRINTK("clip_start_xmit (skb %p)\n",skb);
395 	if (!skb->dst) {
396 		printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
397 		dev_kfree_skb(skb);
398 		clip_priv->stats.tx_dropped++;
399 		return 0;
400 	}
401 	if (!skb->dst->neighbour) {
402 #if 0
403 		skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
404 		if (!skb->dst->neighbour) {
405 			dev_kfree_skb(skb); /* lost that one */
406 			clip_priv->stats.tx_dropped++;
407 			return 0;
408 		}
409 #endif
410 		printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
411 		dev_kfree_skb(skb);
412 		clip_priv->stats.tx_dropped++;
413 		return 0;
414 	}
415 	entry = NEIGH2ENTRY(skb->dst->neighbour);
416 	if (!entry->vccs) {
417 		if (time_after(jiffies, entry->expires)) {
418 			/* should be resolved */
419 			entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
420 			to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
421 		}
422 		if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
423 			skb_queue_tail(&entry->neigh->arp_queue,skb);
424 		else {
425 			dev_kfree_skb(skb);
426 			clip_priv->stats.tx_dropped++;
427 		}
428 		return 0;
429 	}
430 	DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
431 	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
432 	DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
433 	if (entry->vccs->encap) {
434 		void *here;
435 
436 		here = skb_push(skb,RFC1483LLC_LEN);
437 		memcpy(here,llc_oui,sizeof(llc_oui));
438 		((u16 *) here)[3] = skb->protocol;
439 	}
440 	atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
441 	ATM_SKB(skb)->atm_options = vcc->atm_options;
442 	entry->vccs->last_use = jiffies;
443 	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
444 	old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
445 	if (old) {
446 		printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
447 		return 0;
448 	}
449 	clip_priv->stats.tx_packets++;
450 	clip_priv->stats.tx_bytes += skb->len;
451 	(void) vcc->send(vcc,skb);
452 	if (atm_may_send(vcc,0)) {
453 		entry->vccs->xoff = 0;
454 		return 0;
455 	}
456 	spin_lock_irqsave(&clip_priv->xoff_lock,flags);
457 	netif_stop_queue(dev); /* XOFF -> throttle immediately */
458 	barrier();
459 	if (!entry->vccs->xoff)
460 		netif_start_queue(dev);
461 		/* Oh, we just raced with clip_pop. netif_start_queue should be
462 		   good enough, because nothing should really be asleep because
463 		   of the brief netif_stop_queue. If this isn't true or if it
464 		   changes, use netif_wake_queue instead. */
465 	spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
466 	return 0;
467 }
468 
469 
470 static struct net_device_stats *clip_get_stats(struct net_device *dev)
471 {
472 	return &PRIV(dev)->stats;
473 }
474 
475 
476 static int clip_mkip(struct atm_vcc *vcc,int timeout)
477 {
478 	struct clip_vcc *clip_vcc;
479 	struct sk_buff_head copy;
480 	struct sk_buff *skb;
481 
482 	if (!vcc->push) return -EBADFD;
483 	clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
484 	if (!clip_vcc) return -ENOMEM;
485 	DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
486 	clip_vcc->vcc = vcc;
487 	vcc->user_back = clip_vcc;
488 	set_bit(ATM_VF_IS_CLIP, &vcc->flags);
489 	clip_vcc->entry = NULL;
490 	clip_vcc->xoff = 0;
491 	clip_vcc->encap = 1;
492 	clip_vcc->last_use = jiffies;
493 	clip_vcc->idle_timeout = timeout*HZ;
494 	clip_vcc->old_push = vcc->push;
495 	clip_vcc->old_pop = vcc->pop;
496 	vcc->push = clip_push;
497 	vcc->pop = clip_pop;
498 	skb_queue_head_init(&copy);
499 	skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
500 	/* re-process everything received between connection setup and MKIP */
501 	while ((skb = skb_dequeue(&copy)) != NULL)
502 		if (!clip_devs) {
503 			atm_return(vcc,skb->truesize);
504 			kfree_skb(skb);
505 		}
506 		else {
507 			unsigned int len = skb->len;
508 
509 			clip_push(vcc,skb);
510 			PRIV(skb->dev)->stats.rx_packets--;
511 			PRIV(skb->dev)->stats.rx_bytes -= len;
512 		}
513 	return 0;
514 }
515 
516 
517 static int clip_setentry(struct atm_vcc *vcc,u32 ip)
518 {
519 	struct neighbour *neigh;
520 	struct atmarp_entry *entry;
521 	int error;
522 	struct clip_vcc *clip_vcc;
523 	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1 } } };
524 	struct rtable *rt;
525 
526 	if (vcc->push != clip_push) {
527 		printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
528 		return -EBADF;
529 	}
530 	clip_vcc = CLIP_VCC(vcc);
531 	if (!ip) {
532 		if (!clip_vcc->entry) {
533 			printk(KERN_ERR "hiding hidden ATMARP entry\n");
534 			return 0;
535 		}
536 		DPRINTK("setentry: remove\n");
537 		unlink_clip_vcc(clip_vcc);
538 		return 0;
539 	}
540 	error = ip_route_output_key(&rt,&fl);
541 	if (error) return error;
542 	neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
543 	ip_rt_put(rt);
544 	if (!neigh)
545 		return -ENOMEM;
546 	entry = NEIGH2ENTRY(neigh);
547 	if (entry != clip_vcc->entry) {
548 		if (!clip_vcc->entry) DPRINTK("setentry: add\n");
549 		else {
550 			DPRINTK("setentry: update\n");
551 			unlink_clip_vcc(clip_vcc);
552 		}
553 		link_vcc(clip_vcc,entry);
554 	}
555 	error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
556 			     NEIGH_UPDATE_F_OVERRIDE|NEIGH_UPDATE_F_ADMIN);
557 	neigh_release(neigh);
558 	return error;
559 }
560 
561 
562 static void clip_setup(struct net_device *dev)
563 {
564 	dev->hard_start_xmit = clip_start_xmit;
565 	/* sg_xmit ... */
566 	dev->get_stats = clip_get_stats;
567 	dev->type = ARPHRD_ATM;
568 	dev->hard_header_len = RFC1483LLC_LEN;
569 	dev->mtu = RFC1626_MTU;
570 	dev->tx_queue_len = 100; /* "normal" queue (packets) */
571 	    /* When using a "real" qdisc, the qdisc determines the queue */
572 	    /* length. tx_queue_len is only used for the default case, */
573 	    /* without any more elaborate queuing. 100 is a reasonable */
574 	    /* compromise between decent burst-tolerance and protection */
575 	    /* against memory hogs. */
576 }
577 
578 
579 static int clip_create(int number)
580 {
581 	struct net_device *dev;
582 	struct clip_priv *clip_priv;
583 	int error;
584 
585 	if (number != -1) {
586 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
587 			if (PRIV(dev)->number == number) return -EEXIST;
588 	}
589 	else {
590 		number = 0;
591 		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
592 			if (PRIV(dev)->number >= number)
593 				number = PRIV(dev)->number+1;
594 	}
595 	dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
596 	if (!dev)
597 		return -ENOMEM;
598 	clip_priv = PRIV(dev);
599 	sprintf(dev->name,"atm%d",number);
600 	spin_lock_init(&clip_priv->xoff_lock);
601 	clip_priv->number = number;
602 	error = register_netdev(dev);
603 	if (error) {
604 		free_netdev(dev);
605 		return error;
606 	}
607 	clip_priv->next = clip_devs;
608 	clip_devs = dev;
609 	DPRINTK("registered (net:%s)\n",dev->name);
610 	return number;
611 }
612 
613 
614 static int clip_device_event(struct notifier_block *this,unsigned long event,
615     void *dev)
616 {
617 	/* ignore non-CLIP devices */
618 	if (((struct net_device *) dev)->type != ARPHRD_ATM ||
619 	    ((struct net_device *) dev)->hard_start_xmit != clip_start_xmit)
620 		return NOTIFY_DONE;
621 	switch (event) {
622 		case NETDEV_UP:
623 			DPRINTK("clip_device_event NETDEV_UP\n");
624 			(void) to_atmarpd(act_up,PRIV(dev)->number,0);
625 			break;
626 		case NETDEV_GOING_DOWN:
627 			DPRINTK("clip_device_event NETDEV_DOWN\n");
628 			(void) to_atmarpd(act_down,PRIV(dev)->number,0);
629 			break;
630 		case NETDEV_CHANGE:
631 		case NETDEV_CHANGEMTU:
632 			DPRINTK("clip_device_event NETDEV_CHANGE*\n");
633 			(void) to_atmarpd(act_change,PRIV(dev)->number,0);
634 			break;
635 		case NETDEV_REBOOT:
636 		case NETDEV_REGISTER:
637 		case NETDEV_DOWN:
638 			DPRINTK("clip_device_event %ld\n",event);
639 			/* ignore */
640 			break;
641 		default:
642 			printk(KERN_WARNING "clip_device_event: unknown event "
643 			    "%ld\n",event);
644 			break;
645 	}
646 	return NOTIFY_DONE;
647 }
648 
649 
650 static int clip_inet_event(struct notifier_block *this,unsigned long event,
651     void *ifa)
652 {
653 	struct in_device *in_dev;
654 
655 	in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
656 	if (!in_dev || !in_dev->dev) {
657 		printk(KERN_WARNING "clip_inet_event: no device\n");
658 		return NOTIFY_DONE;
659 	}
660 	/*
661 	 * Transitions are of the down-change-up type, so it's sufficient to
662 	 * handle the change on up.
663 	 */
664 	if (event != NETDEV_UP) return NOTIFY_DONE;
665 	return clip_device_event(this,NETDEV_CHANGE,in_dev->dev);
666 }
667 
668 
669 static struct notifier_block clip_dev_notifier = {
670 	clip_device_event,
671 	NULL,
672 	0
673 };
674 
675 
676 
677 static struct notifier_block clip_inet_notifier = {
678 	clip_inet_event,
679 	NULL,
680 	0
681 };
682 
683 
684 
685 static void atmarpd_close(struct atm_vcc *vcc)
686 {
687 	DPRINTK("atmarpd_close\n");
688 	atmarpd = NULL; /* assumed to be atomic */
689 	barrier();
690 	unregister_inetaddr_notifier(&clip_inet_notifier);
691 	unregister_netdevice_notifier(&clip_dev_notifier);
692 	if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
693 		printk(KERN_ERR "atmarpd_close: closing with requests "
694 		    "pending\n");
695 	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
696 	DPRINTK("(done)\n");
697 	module_put(THIS_MODULE);
698 }
699 
700 
701 static struct atmdev_ops atmarpd_dev_ops = {
702 	.close = atmarpd_close
703 };
704 
705 
706 static struct atm_dev atmarpd_dev = {
707 	.ops =			&atmarpd_dev_ops,
708 	.type =			"arpd",
709 	.number = 		999,
710 	.lock =			SPIN_LOCK_UNLOCKED
711 };
712 
713 
714 static int atm_init_atmarp(struct atm_vcc *vcc)
715 {
716 	if (atmarpd) return -EADDRINUSE;
717 	if (start_timer) {
718 		start_timer = 0;
719 		init_timer(&idle_timer);
720 		idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
721 		idle_timer.function = idle_timer_check;
722 		add_timer(&idle_timer);
723 	}
724 	atmarpd = vcc;
725 	set_bit(ATM_VF_META,&vcc->flags);
726 	set_bit(ATM_VF_READY,&vcc->flags);
727 	    /* allow replies and avoid getting closed if signaling dies */
728 	vcc->dev = &atmarpd_dev;
729 	vcc_insert_socket(sk_atm(vcc));
730 	vcc->push = NULL;
731 	vcc->pop = NULL; /* crash */
732 	vcc->push_oam = NULL; /* crash */
733 	if (register_netdevice_notifier(&clip_dev_notifier))
734 		printk(KERN_ERR "register_netdevice_notifier failed\n");
735 	if (register_inetaddr_notifier(&clip_inet_notifier))
736 		printk(KERN_ERR "register_inetaddr_notifier failed\n");
737 	return 0;
738 }
739 
740 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
741 {
742 	struct atm_vcc *vcc = ATM_SD(sock);
743 	int err = 0;
744 
745 	switch (cmd) {
746 		case SIOCMKCLIP:
747 		case ATMARPD_CTRL:
748 		case ATMARP_MKIP:
749 		case ATMARP_SETENTRY:
750 		case ATMARP_ENCAP:
751 			if (!capable(CAP_NET_ADMIN))
752 				return -EPERM;
753 			break;
754 		default:
755 			return -ENOIOCTLCMD;
756 	}
757 
758 	switch (cmd) {
759 		case SIOCMKCLIP:
760 			err = clip_create(arg);
761 			break;
762 		case ATMARPD_CTRL:
763 			err = atm_init_atmarp(vcc);
764 			if (!err) {
765 				sock->state = SS_CONNECTED;
766 				__module_get(THIS_MODULE);
767 			}
768 			break;
769 		case ATMARP_MKIP:
770 			err = clip_mkip(vcc ,arg);
771 			break;
772 		case ATMARP_SETENTRY:
773 			err = clip_setentry(vcc, arg);
774 			break;
775 		case ATMARP_ENCAP:
776 			err = clip_encap(vcc, arg);
777 			break;
778 	}
779 	return err;
780 }
781 
782 static struct atm_ioctl clip_ioctl_ops = {
783 	.owner 	= THIS_MODULE,
784 	.ioctl	= clip_ioctl,
785 };
786 
787 #ifdef CONFIG_PROC_FS
788 
789 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
790 {
791 	static int code[] = { 1,2,10,6,1,0 };
792 	static int e164[] = { 1,8,4,6,1,0 };
793 
794 	if (*addr->sas_addr.pub) {
795 		seq_printf(seq, "%s", addr->sas_addr.pub);
796 		if (*addr->sas_addr.prv)
797 			seq_putc(seq, '+');
798 	} else if (!*addr->sas_addr.prv) {
799 		seq_printf(seq, "%s", "(none)");
800 		return;
801 	}
802 	if (*addr->sas_addr.prv) {
803 		unsigned char *prv = addr->sas_addr.prv;
804 		int *fields;
805 		int i, j;
806 
807 		fields = *prv == ATM_AFI_E164 ? e164 : code;
808 		for (i = 0; fields[i]; i++) {
809 			for (j = fields[i]; j; j--)
810 				seq_printf(seq, "%02X", *prv++);
811 			if (fields[i+1])
812 				seq_putc(seq, '.');
813 		}
814 	}
815 }
816 
817 /* This means the neighbour entry has no attached VCC objects. */
818 #define SEQ_NO_VCC_TOKEN	((void *) 2)
819 
820 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
821 			struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
822 {
823 	unsigned long exp;
824 	char buf[17];
825 	int svc, llc, off;
826 
827 	svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
828 	       (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
829 
830 	llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
831 	       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,
842 		   svc ? "SVC" : "PVC",
843 		   llc ? "LLC" : "NULL",
844 		   exp);
845 
846 	off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
847 			NIPQUAD(entry->ip));
848 	while (off < 16)
849 		buf[off++] = ' ';
850 	buf[off] = '\0';
851 	seq_printf(seq, "%s", buf);
852 
853 	if (clip_vcc == SEQ_NO_VCC_TOKEN) {
854 		if (time_before(jiffies, entry->expires))
855 			seq_printf(seq, "(resolving)\n");
856 		else
857 			seq_printf(seq, "(expired, ref %d)\n",
858 				   atomic_read(&entry->neigh->refcnt));
859 	} else if (!svc) {
860 		seq_printf(seq, "%d.%d.%d\n",
861 			   clip_vcc->vcc->dev->number,
862 			   clip_vcc->vcc->vpi,
863 			   clip_vcc->vcc->vci);
864 	} else {
865 		svc_addr(seq, &clip_vcc->vcc->remote);
866 		seq_putc(seq, '\n');
867 	}
868 }
869 
870 struct clip_seq_state {
871 	/* This member must be first. */
872 	struct neigh_seq_state ns;
873 
874 	/* Local to clip specific iteration. */
875 	struct clip_vcc *vcc;
876 };
877 
878 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
879 					  struct clip_vcc *curr)
880 {
881 	if (!curr) {
882 		curr = e->vccs;
883 		if (!curr)
884 			return SEQ_NO_VCC_TOKEN;
885 		return curr;
886 	}
887 	if (curr == SEQ_NO_VCC_TOKEN)
888 		return NULL;
889 
890 	curr = curr->next;
891 
892 	return curr;
893 }
894 
895 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
896 			       struct atmarp_entry *e, loff_t *pos)
897 {
898 	struct clip_vcc *vcc = state->vcc;
899 
900 	vcc = clip_seq_next_vcc(e, vcc);
901 	if (vcc && pos != NULL) {
902 		while (*pos) {
903 			vcc = clip_seq_next_vcc(e, vcc);
904 			if (!vcc)
905 				break;
906 			--(*pos);
907 		}
908 	}
909 	state->vcc = vcc;
910 
911 	return vcc;
912 }
913 
914 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
915 			       struct neighbour *n, loff_t *pos)
916 {
917 	struct clip_seq_state *state = (struct clip_seq_state *) _state;
918 
919 	return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
920 }
921 
922 static void *clip_seq_start(struct seq_file *seq, loff_t *pos)
923 {
924 	return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
925 }
926 
927 static int clip_seq_show(struct seq_file *seq, void *v)
928 {
929 	static char atm_arp_banner[] =
930 		"IPitf TypeEncp Idle IP address      ATM address\n";
931 
932 	if (v == SEQ_START_TOKEN) {
933 		seq_puts(seq, atm_arp_banner);
934 	} else {
935 		struct clip_seq_state *state = seq->private;
936 		struct neighbour *n = v;
937 		struct clip_vcc *vcc = state->vcc;
938 
939 		atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
940 	}
941   	return 0;
942 }
943 
944 static struct seq_operations arp_seq_ops = {
945 	.start	= clip_seq_start,
946 	.next	= neigh_seq_next,
947 	.stop	= neigh_seq_stop,
948 	.show	= clip_seq_show,
949 };
950 
951 static int arp_seq_open(struct inode *inode, struct file *file)
952 {
953 	struct clip_seq_state *state;
954 	struct seq_file *seq;
955 	int rc = -EAGAIN;
956 
957 	state = kmalloc(sizeof(*state), GFP_KERNEL);
958 	if (!state) {
959 		rc = -ENOMEM;
960 		goto out_kfree;
961 	}
962 	memset(state, 0, sizeof(*state));
963 	state->ns.neigh_sub_iter = clip_seq_sub_iter;
964 
965 	rc = seq_open(file, &arp_seq_ops);
966 	if (rc)
967 		goto out_kfree;
968 
969 	seq = file->private_data;
970 	seq->private = state;
971 out:
972 	return rc;
973 
974 out_kfree:
975 	kfree(state);
976 	goto out;
977 }
978 
979 static struct file_operations arp_seq_fops = {
980 	.open		= arp_seq_open,
981 	.read		= seq_read,
982 	.llseek		= seq_lseek,
983 	.release	= seq_release_private,
984 	.owner		= THIS_MODULE
985 };
986 #endif
987 
988 static int __init atm_clip_init(void)
989 {
990 	neigh_table_init(&clip_tbl);
991 
992 	clip_tbl_hook = &clip_tbl;
993 	register_atm_ioctl(&clip_ioctl_ops);
994 
995 #ifdef CONFIG_PROC_FS
996 {
997 	struct proc_dir_entry *p;
998 
999 	p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
1000 	if (p)
1001 		p->proc_fops = &arp_seq_fops;
1002 }
1003 #endif
1004 
1005 	return 0;
1006 }
1007 
1008 static void __exit atm_clip_exit(void)
1009 {
1010 	struct net_device *dev, *next;
1011 
1012 	remove_proc_entry("arp", atm_proc_root);
1013 
1014 	deregister_atm_ioctl(&clip_ioctl_ops);
1015 
1016 	/* First, stop the idle timer, so it stops banging
1017 	 * on the table.
1018 	 */
1019 	if (start_timer == 0)
1020 		del_timer(&idle_timer);
1021 
1022 	/* Next, purge the table, so that the device
1023 	 * unregister loop below does not hang due to
1024 	 * device references remaining in the table.
1025 	 */
1026 	neigh_ifdown(&clip_tbl, NULL);
1027 
1028 	dev = clip_devs;
1029 	while (dev) {
1030 		next = PRIV(dev)->next;
1031 		unregister_netdev(dev);
1032 		free_netdev(dev);
1033 		dev = next;
1034 	}
1035 
1036 	/* Now it is safe to fully shutdown whole table. */
1037 	neigh_table_clear(&clip_tbl);
1038 
1039 	clip_tbl_hook = NULL;
1040 }
1041 
1042 module_init(atm_clip_init);
1043 module_exit(atm_clip_exit);
1044 
1045 MODULE_LICENSE("GPL");
1046