xref: /openbmc/linux/net/atm/br2684.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2 Experimental ethernet netdevice using ATM AAL5 as underlying carrier
3 (RFC1483 obsoleted by RFC2684) for Linux 2.4
4 Author: Marcell GAL, 2000, XDSL Ltd, Hungary
5 */
6 
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/list.h>
11 #include <linux/netdevice.h>
12 #include <linux/skbuff.h>
13 #include <linux/etherdevice.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/ip.h>
16 #include <asm/uaccess.h>
17 #include <net/arp.h>
18 #include <linux/atm.h>
19 #include <linux/atmdev.h>
20 #include <linux/capability.h>
21 #include <linux/seq_file.h>
22 
23 #include <linux/atmbr2684.h>
24 
25 #include "common.h"
26 
27 #ifdef SKB_DEBUG
28 static void skb_debug(const struct sk_buff *skb)
29 {
30 #define NUM2PRINT 50
31 	char buf[NUM2PRINT * 3 + 1];	/* 3 chars per byte */
32 	int i = 0;
33 	for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
34 		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
35 	}
36 	printk(KERN_DEBUG "br2684: skb: %s\n", buf);
37 }
38 #else
39 #define skb_debug(skb)	do {} while (0)
40 #endif
41 
42 static unsigned char llc_oui_pid_pad[] =
43     { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
44 #define PADLEN	(2)
45 
46 enum br2684_encaps {
47 	e_vc  = BR2684_ENCAPS_VC,
48 	e_llc = BR2684_ENCAPS_LLC,
49 };
50 
51 struct br2684_vcc {
52 	struct atm_vcc  *atmvcc;
53 	struct net_device *device;
54 	/* keep old push,pop functions for chaining */
55 	void (*old_push)(struct atm_vcc *vcc,struct sk_buff *skb);
56 	/* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
57 	enum br2684_encaps encaps;
58 	struct list_head brvccs;
59 #ifdef CONFIG_ATM_BR2684_IPFILTER
60 	struct br2684_filter filter;
61 #endif /* CONFIG_ATM_BR2684_IPFILTER */
62 	unsigned copies_needed, copies_failed;
63 };
64 
65 struct br2684_dev {
66 	struct net_device *net_dev;
67 	struct list_head br2684_devs;
68 	int number;
69 	struct list_head brvccs; /* one device <=> one vcc (before xmas) */
70 	struct net_device_stats stats;
71 	int mac_was_set;
72 };
73 
74 /*
75  * This lock should be held for writing any time the list of devices or
76  * their attached vcc's could be altered.  It should be held for reading
77  * any time these are being queried.  Note that we sometimes need to
78  * do read-locking under interrupt context, so write locking must block
79  * the current CPU's interrupts
80  */
81 static DEFINE_RWLOCK(devs_lock);
82 
83 static LIST_HEAD(br2684_devs);
84 
85 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
86 {
87 	return (struct br2684_dev *) net_dev->priv;
88 }
89 
90 static inline struct net_device *list_entry_brdev(const struct list_head *le)
91 {
92 	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
93 }
94 
95 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
96 {
97 	return (struct br2684_vcc *) (atmvcc->user_back);
98 }
99 
100 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
101 {
102 	return list_entry(le, struct br2684_vcc, brvccs);
103 }
104 
105 /* Caller should hold read_lock(&devs_lock) */
106 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
107 {
108 	struct list_head *lh;
109 	struct net_device *net_dev;
110 	switch (s->method) {
111 	case BR2684_FIND_BYNUM:
112 		list_for_each(lh, &br2684_devs) {
113 			net_dev = list_entry_brdev(lh);
114 			if (BRPRIV(net_dev)->number == s->spec.devnum)
115 				return net_dev;
116 		}
117 		break;
118 	case BR2684_FIND_BYIFNAME:
119 		list_for_each(lh, &br2684_devs) {
120 			net_dev = list_entry_brdev(lh);
121 			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
122 				return net_dev;
123 		}
124 		break;
125 	}
126 	return NULL;
127 }
128 
129 /*
130  * Send a packet out a particular vcc.  Not to useful right now, but paves
131  * the way for multiple vcc's per itf.  Returns true if we can send,
132  * otherwise false
133  */
134 static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
135 	struct br2684_vcc *brvcc)
136 {
137 	struct atm_vcc *atmvcc;
138 	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
139 	if (skb_headroom(skb) < minheadroom) {
140 		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
141 		brvcc->copies_needed++;
142 		dev_kfree_skb(skb);
143 		if (skb2 == NULL) {
144 			brvcc->copies_failed++;
145 			return 0;
146 		}
147 		skb = skb2;
148 	}
149 	skb_push(skb, minheadroom);
150 	if (brvcc->encaps == e_llc)
151 		skb_copy_to_linear_data(skb, llc_oui_pid_pad, 10);
152 	else
153 		memset(skb->data, 0, 2);
154 	skb_debug(skb);
155 
156 	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
157 	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
158 	if (!atm_may_send(atmvcc, skb->truesize)) {
159 		/* we free this here for now, because we cannot know in a higher
160 			layer whether the skb point it supplied wasn't freed yet.
161 			now, it always is.
162 		*/
163 		dev_kfree_skb(skb);
164 		return 0;
165 		}
166 	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
167 	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
168 	brdev->stats.tx_packets++;
169 	brdev->stats.tx_bytes += skb->len;
170 	atmvcc->send(atmvcc, skb);
171 	return 1;
172 }
173 
174 static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb,
175 	struct br2684_dev *brdev)
176 {
177 	return list_empty(&brdev->brvccs) ? NULL :
178 	    list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */
179 }
180 
181 static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
182 {
183 	struct br2684_dev *brdev = BRPRIV(dev);
184 	struct br2684_vcc *brvcc;
185 
186 	pr_debug("br2684_start_xmit, skb->dst=%p\n", skb->dst);
187 	read_lock(&devs_lock);
188 	brvcc = pick_outgoing_vcc(skb, brdev);
189 	if (brvcc == NULL) {
190 		pr_debug("no vcc attached to dev %s\n", dev->name);
191 		brdev->stats.tx_errors++;
192 		brdev->stats.tx_carrier_errors++;
193 		/* netif_stop_queue(dev); */
194 		dev_kfree_skb(skb);
195 		read_unlock(&devs_lock);
196 		return 0;
197 	}
198 	if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
199 		/*
200 		 * We should probably use netif_*_queue() here, but that
201 		 * involves added complication.  We need to walk before
202 		 * we can run
203 		 */
204 		/* don't free here! this pointer might be no longer valid!
205 		dev_kfree_skb(skb);
206 		*/
207 		brdev->stats.tx_errors++;
208 		brdev->stats.tx_fifo_errors++;
209 	}
210 	read_unlock(&devs_lock);
211 	return 0;
212 }
213 
214 static struct net_device_stats *br2684_get_stats(struct net_device *dev)
215 {
216 	pr_debug("br2684_get_stats\n");
217 	return &BRPRIV(dev)->stats;
218 }
219 
220 
221 /*
222  * We remember when the MAC gets set, so we don't override it later with
223  * the ESI of the ATM card of the first VC
224  */
225 static int (*my_eth_mac_addr)(struct net_device *, void *);
226 static int br2684_mac_addr(struct net_device *dev, void *p)
227 {
228 	int err = my_eth_mac_addr(dev, p);
229 	if (!err)
230 		BRPRIV(dev)->mac_was_set = 1;
231 	return err;
232 }
233 
234 #ifdef CONFIG_ATM_BR2684_IPFILTER
235 /* this IOCTL is experimental. */
236 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user *arg)
237 {
238 	struct br2684_vcc *brvcc;
239 	struct br2684_filter_set fs;
240 
241 	if (copy_from_user(&fs, arg, sizeof fs))
242 		return -EFAULT;
243 	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
244 		/*
245 		 * This is really a per-vcc thing, but we can also search
246 		 * by device
247 		 */
248 		struct br2684_dev *brdev;
249 		read_lock(&devs_lock);
250 		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
251 		if (brdev == NULL || list_empty(&brdev->brvccs) ||
252 		    brdev->brvccs.next != brdev->brvccs.prev)  /* >1 VCC */
253 			brvcc = NULL;
254 		else
255 			brvcc = list_entry_brvcc(brdev->brvccs.next);
256 		read_unlock(&devs_lock);
257 		if (brvcc == NULL)
258 			return -ESRCH;
259 	} else
260 		brvcc = BR2684_VCC(atmvcc);
261 	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
262 	return 0;
263 }
264 
265 /* Returns 1 if packet should be dropped */
266 static inline int
267 packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
268 {
269 	if (brvcc->filter.netmask == 0)
270 		return 0;			/* no filter in place */
271 	if (type == htons(ETH_P_IP) &&
272 	    (((struct iphdr *) (skb->data))->daddr & brvcc->filter.
273 	     netmask) == brvcc->filter.prefix)
274 		return 0;
275 	if (type == htons(ETH_P_ARP))
276 		return 0;
277 	/* TODO: we should probably filter ARPs too.. don't want to have
278 	 *   them returning values that don't make sense, or is that ok?
279 	 */
280 	return 1;		/* drop */
281 }
282 #endif /* CONFIG_ATM_BR2684_IPFILTER */
283 
284 static void br2684_close_vcc(struct br2684_vcc *brvcc)
285 {
286 	pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
287 	write_lock_irq(&devs_lock);
288 	list_del(&brvcc->brvccs);
289 	write_unlock_irq(&devs_lock);
290 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
291 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
292 	kfree(brvcc);
293 	module_put(THIS_MODULE);
294 }
295 
296 /* when AAL5 PDU comes in: */
297 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
298 {
299 	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
300 	struct net_device *net_dev = brvcc->device;
301 	struct br2684_dev *brdev = BRPRIV(net_dev);
302 	int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
303 
304 	pr_debug("br2684_push\n");
305 
306 	if (unlikely(skb == NULL)) {
307 		/* skb==NULL means VCC is being destroyed */
308 		br2684_close_vcc(brvcc);
309 		if (list_empty(&brdev->brvccs)) {
310 			read_lock(&devs_lock);
311 			list_del(&brdev->br2684_devs);
312 			read_unlock(&devs_lock);
313 			unregister_netdev(net_dev);
314 			free_netdev(net_dev);
315 		}
316 		return;
317 	}
318 
319 	skb_debug(skb);
320 	atm_return(atmvcc, skb->truesize);
321 	pr_debug("skb from brdev %p\n", brdev);
322 	if (brvcc->encaps == e_llc) {
323 		/* let us waste some time for checking the encapsulation.
324 		   Note, that only 7 char is checked so frames with a valid FCS
325 		   are also accepted (but FCS is not checked of course) */
326 		if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
327 			brdev->stats.rx_errors++;
328 			dev_kfree_skb(skb);
329 			return;
330 		}
331 
332 		/* Strip FCS if present */
333 		if (skb->len > 7 && skb->data[7] == 0x01)
334 			__skb_trim(skb, skb->len - 4);
335 	} else {
336 		plen = PADLEN + ETH_HLEN;	/* pad, dstmac,srcmac, ethtype */
337 		/* first 2 chars should be 0 */
338 		if (*((u16 *) (skb->data)) != 0) {
339 			brdev->stats.rx_errors++;
340 			dev_kfree_skb(skb);
341 			return;
342 		}
343 	}
344 	if (skb->len < plen) {
345 		brdev->stats.rx_errors++;
346 		dev_kfree_skb(skb);	/* dev_ not needed? */
347 		return;
348 	}
349 
350 	skb_pull(skb, plen - ETH_HLEN);
351 	skb->protocol = eth_type_trans(skb, net_dev);
352 #ifdef CONFIG_ATM_BR2684_IPFILTER
353 	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
354 		brdev->stats.rx_dropped++;
355 		dev_kfree_skb(skb);
356 		return;
357 	}
358 #endif /* CONFIG_ATM_BR2684_IPFILTER */
359 	skb->dev = net_dev;
360 	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
361 	pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
362 	skb_debug(skb);
363 	if (unlikely(!(net_dev->flags & IFF_UP))) {
364 		/* sigh, interface is down */
365 		brdev->stats.rx_dropped++;
366 		dev_kfree_skb(skb);
367 		return;
368 	}
369 	brdev->stats.rx_packets++;
370 	brdev->stats.rx_bytes += skb->len;
371 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
372 	netif_rx(skb);
373 }
374 
375 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user *arg)
376 {
377 /* assign a vcc to a dev
378 Note: we do not have explicit unassign, but look at _push()
379 */
380 	int err;
381 	struct br2684_vcc *brvcc;
382 	struct sk_buff *skb;
383 	struct sk_buff_head *rq;
384 	struct br2684_dev *brdev;
385 	struct net_device *net_dev;
386 	struct atm_backend_br2684 be;
387 	unsigned long flags;
388 
389 	if (copy_from_user(&be, arg, sizeof be))
390 		return -EFAULT;
391 	brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
392 	if (!brvcc)
393 		return -ENOMEM;
394 	write_lock_irq(&devs_lock);
395 	net_dev = br2684_find_dev(&be.ifspec);
396 	if (net_dev == NULL) {
397 		printk(KERN_ERR
398 		    "br2684: tried to attach to non-existant device\n");
399 		err = -ENXIO;
400 		goto error;
401 	}
402 	brdev = BRPRIV(net_dev);
403 	if (atmvcc->push == NULL) {
404 		err = -EBADFD;
405 		goto error;
406 	}
407 	if (!list_empty(&brdev->brvccs)) {
408 		/* Only 1 VCC/dev right now */
409 		err = -EEXIST;
410 		goto error;
411 	}
412 	if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
413 	    be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
414 	    BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
415 	    be.min_size != 0) {
416 		err = -EINVAL;
417 		goto error;
418 	}
419 	pr_debug("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
420 		brvcc);
421 	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
422 		unsigned char *esi = atmvcc->dev->esi;
423 		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
424 			memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
425 		else
426 			net_dev->dev_addr[2] = 1;
427 	}
428 	list_add(&brvcc->brvccs, &brdev->brvccs);
429 	write_unlock_irq(&devs_lock);
430 	brvcc->device = net_dev;
431 	brvcc->atmvcc = atmvcc;
432 	atmvcc->user_back = brvcc;
433 	brvcc->encaps = (enum br2684_encaps) be.encaps;
434 	brvcc->old_push = atmvcc->push;
435 	barrier();
436 	atmvcc->push = br2684_push;
437 
438 	rq = &sk_atm(atmvcc)->sk_receive_queue;
439 
440 	spin_lock_irqsave(&rq->lock, flags);
441 	if (skb_queue_empty(rq)) {
442 		skb = NULL;
443 	} else {
444 		/* NULL terminate the list.  */
445 		rq->prev->next = NULL;
446 		skb = rq->next;
447 	}
448 	rq->prev = rq->next = (struct sk_buff *)rq;
449 	rq->qlen = 0;
450 	spin_unlock_irqrestore(&rq->lock, flags);
451 
452 	while (skb) {
453 		struct sk_buff *next = skb->next;
454 
455 		skb->next = skb->prev = NULL;
456 		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
457 		BRPRIV(skb->dev)->stats.rx_packets--;
458 		br2684_push(atmvcc, skb);
459 
460 		skb = next;
461 	}
462 	__module_get(THIS_MODULE);
463 	return 0;
464     error:
465 	write_unlock_irq(&devs_lock);
466 	kfree(brvcc);
467 	return err;
468 }
469 
470 static void br2684_setup(struct net_device *netdev)
471 {
472 	struct br2684_dev *brdev = BRPRIV(netdev);
473 
474 	ether_setup(netdev);
475 	brdev->net_dev = netdev;
476 
477 	my_eth_mac_addr = netdev->set_mac_address;
478 	netdev->set_mac_address = br2684_mac_addr;
479 	netdev->hard_start_xmit = br2684_start_xmit;
480 	netdev->get_stats = br2684_get_stats;
481 
482 	INIT_LIST_HEAD(&brdev->brvccs);
483 }
484 
485 static int br2684_create(void __user *arg)
486 {
487 	int err;
488 	struct net_device *netdev;
489 	struct br2684_dev *brdev;
490 	struct atm_newif_br2684 ni;
491 
492 	pr_debug("br2684_create\n");
493 
494 	if (copy_from_user(&ni, arg, sizeof ni)) {
495 		return -EFAULT;
496 	}
497 	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
498 		return -EINVAL;
499 	}
500 
501 	netdev = alloc_netdev(sizeof(struct br2684_dev),
502 			      ni.ifname[0] ? ni.ifname : "nas%d",
503 			      br2684_setup);
504 	if (!netdev)
505 		return -ENOMEM;
506 
507 	brdev = BRPRIV(netdev);
508 
509 	pr_debug("registered netdev %s\n", netdev->name);
510 	/* open, stop, do_ioctl ? */
511 	err = register_netdev(netdev);
512 	if (err < 0) {
513 		printk(KERN_ERR "br2684_create: register_netdev failed\n");
514 		free_netdev(netdev);
515 		return err;
516 	}
517 
518 	write_lock_irq(&devs_lock);
519 	brdev->number = list_empty(&br2684_devs) ? 1 :
520 	    BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
521 	list_add_tail(&brdev->br2684_devs, &br2684_devs);
522 	write_unlock_irq(&devs_lock);
523 	return 0;
524 }
525 
526 /*
527  * This handles ioctls actually performed on our vcc - we must return
528  * -ENOIOCTLCMD for any unrecognized ioctl
529  */
530 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
531 	unsigned long arg)
532 {
533 	struct atm_vcc *atmvcc = ATM_SD(sock);
534 	void __user *argp = (void __user *)arg;
535 
536 	int err;
537 	switch(cmd) {
538 	case ATM_SETBACKEND:
539 	case ATM_NEWBACKENDIF: {
540 		atm_backend_t b;
541 		err = get_user(b, (atm_backend_t __user *) argp);
542 		if (err)
543 			return -EFAULT;
544 		if (b != ATM_BACKEND_BR2684)
545 			return -ENOIOCTLCMD;
546 		if (!capable(CAP_NET_ADMIN))
547 			return -EPERM;
548 		if (cmd == ATM_SETBACKEND)
549 			return br2684_regvcc(atmvcc, argp);
550 		else
551 			return br2684_create(argp);
552 		}
553 #ifdef CONFIG_ATM_BR2684_IPFILTER
554 	case BR2684_SETFILT:
555 		if (atmvcc->push != br2684_push)
556 			return -ENOIOCTLCMD;
557 		if (!capable(CAP_NET_ADMIN))
558 			return -EPERM;
559 		err = br2684_setfilt(atmvcc, argp);
560 		return err;
561 #endif /* CONFIG_ATM_BR2684_IPFILTER */
562 	}
563 	return -ENOIOCTLCMD;
564 }
565 
566 static struct atm_ioctl br2684_ioctl_ops = {
567 	.owner	= THIS_MODULE,
568 	.ioctl	= br2684_ioctl,
569 };
570 
571 
572 #ifdef CONFIG_PROC_FS
573 static void *br2684_seq_start(struct seq_file *seq, loff_t *pos)
574 {
575 	read_lock(&devs_lock);
576 	return seq_list_start(&br2684_devs, *pos);
577 }
578 
579 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t *pos)
580 {
581 	return seq_list_next(v, &br2684_devs, pos);
582 }
583 
584 static void br2684_seq_stop(struct seq_file *seq, void *v)
585 {
586 	read_unlock(&devs_lock);
587 }
588 
589 static int br2684_seq_show(struct seq_file *seq, void *v)
590 {
591 	const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
592 			br2684_devs);
593 	const struct net_device *net_dev = brdev->net_dev;
594 	const struct br2684_vcc *brvcc;
595 	DECLARE_MAC_BUF(mac);
596 
597 	seq_printf(seq, "dev %.16s: num=%d, mac=%s (%s)\n",
598 		   net_dev->name,
599 		   brdev->number,
600 		   print_mac(mac, net_dev->dev_addr),
601 		   brdev->mac_was_set ? "set" : "auto");
602 
603 	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
604 		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
605 				    ", failed copies %u/%u"
606 				    "\n", brvcc->atmvcc->dev->number,
607 				    brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
608 				    (brvcc->encaps == e_llc) ? "LLC" : "VC"
609 				    , brvcc->copies_failed
610 				    , brvcc->copies_needed
611 				    );
612 #ifdef CONFIG_ATM_BR2684_IPFILTER
613 #define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
614 #define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
615 			if (brvcc->filter.netmask != 0)
616 				seq_printf(seq, "    filter=%d.%d.%d.%d/"
617 						"%d.%d.%d.%d\n",
618 						bs(prefix), bs(netmask));
619 #undef bs
620 #undef b1
621 #endif /* CONFIG_ATM_BR2684_IPFILTER */
622 	}
623 	return 0;
624 }
625 
626 static const struct seq_operations br2684_seq_ops = {
627 	.start = br2684_seq_start,
628 	.next  = br2684_seq_next,
629 	.stop  = br2684_seq_stop,
630 	.show  = br2684_seq_show,
631 };
632 
633 static int br2684_proc_open(struct inode *inode, struct file *file)
634 {
635 	return seq_open(file, &br2684_seq_ops);
636 }
637 
638 static const struct file_operations br2684_proc_ops = {
639 	.owner   = THIS_MODULE,
640 	.open    = br2684_proc_open,
641 	.read    = seq_read,
642 	.llseek  = seq_lseek,
643 	.release = seq_release,
644 };
645 
646 extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
647 #endif
648 
649 static int __init br2684_init(void)
650 {
651 #ifdef CONFIG_PROC_FS
652 	struct proc_dir_entry *p;
653 	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
654 		return -ENOMEM;
655 	p->proc_fops = &br2684_proc_ops;
656 #endif
657 	register_atm_ioctl(&br2684_ioctl_ops);
658 	return 0;
659 }
660 
661 static void __exit br2684_exit(void)
662 {
663 	struct net_device *net_dev;
664 	struct br2684_dev *brdev;
665 	struct br2684_vcc *brvcc;
666 	deregister_atm_ioctl(&br2684_ioctl_ops);
667 
668 #ifdef CONFIG_PROC_FS
669 	remove_proc_entry("br2684", atm_proc_root);
670 #endif
671 
672 	while (!list_empty(&br2684_devs)) {
673 		net_dev = list_entry_brdev(br2684_devs.next);
674 		brdev = BRPRIV(net_dev);
675 		while (!list_empty(&brdev->brvccs)) {
676 			brvcc = list_entry_brvcc(brdev->brvccs.next);
677 			br2684_close_vcc(brvcc);
678 		}
679 
680 		list_del(&brdev->br2684_devs);
681 		unregister_netdev(net_dev);
682 		free_netdev(net_dev);
683 	}
684 }
685 
686 module_init(br2684_init);
687 module_exit(br2684_exit);
688 
689 MODULE_AUTHOR("Marcell GAL");
690 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
691 MODULE_LICENSE("GPL");
692