xref: /linux/net/atm/br2684.c (revision a1ce39288e6fbefdd8d607021d02384eb4a20b99)
1 /*
2  * Ethernet netdevice using ATM AAL5 as underlying carrier
3  * (RFC1483 obsoleted by RFC2684) for Linux
4  *
5  * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
6  *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
7  */
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
10 
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <linux/netdevice.h>
16 #include <linux/skbuff.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/ip.h>
20 #include <linux/uaccess.h>
21 #include <linux/slab.h>
22 #include <net/arp.h>
23 #include <linux/atm.h>
24 #include <linux/atmdev.h>
25 #include <linux/capability.h>
26 #include <linux/seq_file.h>
27 
28 #include <linux/atmbr2684.h>
29 
30 #include "common.h"
31 
32 static void skb_debug(const struct sk_buff *skb)
33 {
34 #ifdef SKB_DEBUG
35 #define NUM2PRINT 50
36 	print_hex_dump(KERN_DEBUG, "br2684: skb: ", DUMP_OFFSET,
37 		       16, 1, skb->data, min(NUM2PRINT, skb->len), true);
38 #endif
39 }
40 
41 #define BR2684_ETHERTYPE_LEN	2
42 #define BR2684_PAD_LEN		2
43 
44 #define LLC		0xaa, 0xaa, 0x03
45 #define SNAP_BRIDGED	0x00, 0x80, 0xc2
46 #define SNAP_ROUTED	0x00, 0x00, 0x00
47 #define PID_ETHERNET	0x00, 0x07
48 #define ETHERTYPE_IPV4	0x08, 0x00
49 #define ETHERTYPE_IPV6	0x86, 0xdd
50 #define PAD_BRIDGED	0x00, 0x00
51 
52 static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
53 static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
54 static const unsigned char llc_oui_pid_pad[] =
55 			{ LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
56 static const unsigned char pad[] = { PAD_BRIDGED };
57 static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
58 static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
59 
60 enum br2684_encaps {
61 	e_vc = BR2684_ENCAPS_VC,
62 	e_llc = BR2684_ENCAPS_LLC,
63 };
64 
65 struct br2684_vcc {
66 	struct atm_vcc *atmvcc;
67 	struct net_device *device;
68 	/* keep old push, pop functions for chaining */
69 	void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
70 	void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
71 	enum br2684_encaps encaps;
72 	struct list_head brvccs;
73 #ifdef CONFIG_ATM_BR2684_IPFILTER
74 	struct br2684_filter filter;
75 #endif /* CONFIG_ATM_BR2684_IPFILTER */
76 	unsigned int copies_needed, copies_failed;
77 };
78 
79 struct br2684_dev {
80 	struct net_device *net_dev;
81 	struct list_head br2684_devs;
82 	int number;
83 	struct list_head brvccs;	/* one device <=> one vcc (before xmas) */
84 	int mac_was_set;
85 	enum br2684_payload payload;
86 };
87 
88 /*
89  * This lock should be held for writing any time the list of devices or
90  * their attached vcc's could be altered.  It should be held for reading
91  * any time these are being queried.  Note that we sometimes need to
92  * do read-locking under interrupt context, so write locking must block
93  * the current CPU's interrupts
94  */
95 static DEFINE_RWLOCK(devs_lock);
96 
97 static LIST_HEAD(br2684_devs);
98 
99 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
100 {
101 	return netdev_priv(net_dev);
102 }
103 
104 static inline struct net_device *list_entry_brdev(const struct list_head *le)
105 {
106 	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
107 }
108 
109 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
110 {
111 	return (struct br2684_vcc *)(atmvcc->user_back);
112 }
113 
114 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
115 {
116 	return list_entry(le, struct br2684_vcc, brvccs);
117 }
118 
119 /* Caller should hold read_lock(&devs_lock) */
120 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
121 {
122 	struct list_head *lh;
123 	struct net_device *net_dev;
124 	switch (s->method) {
125 	case BR2684_FIND_BYNUM:
126 		list_for_each(lh, &br2684_devs) {
127 			net_dev = list_entry_brdev(lh);
128 			if (BRPRIV(net_dev)->number == s->spec.devnum)
129 				return net_dev;
130 		}
131 		break;
132 	case BR2684_FIND_BYIFNAME:
133 		list_for_each(lh, &br2684_devs) {
134 			net_dev = list_entry_brdev(lh);
135 			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
136 				return net_dev;
137 		}
138 		break;
139 	}
140 	return NULL;
141 }
142 
143 static int atm_dev_event(struct notifier_block *this, unsigned long event,
144 		 void *arg)
145 {
146 	struct atm_dev *atm_dev = arg;
147 	struct list_head *lh;
148 	struct net_device *net_dev;
149 	struct br2684_vcc *brvcc;
150 	struct atm_vcc *atm_vcc;
151 	unsigned long flags;
152 
153 	pr_debug("event=%ld dev=%p\n", event, atm_dev);
154 
155 	read_lock_irqsave(&devs_lock, flags);
156 	list_for_each(lh, &br2684_devs) {
157 		net_dev = list_entry_brdev(lh);
158 
159 		list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
160 			atm_vcc = brvcc->atmvcc;
161 			if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
162 
163 				if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
164 					netif_carrier_off(net_dev);
165 				else
166 					netif_carrier_on(net_dev);
167 
168 			}
169 		}
170 	}
171 	read_unlock_irqrestore(&devs_lock, flags);
172 
173 	return NOTIFY_DONE;
174 }
175 
176 static struct notifier_block atm_dev_notifier = {
177 	.notifier_call = atm_dev_event,
178 };
179 
180 /* chained vcc->pop function.  Check if we should wake the netif_queue */
181 static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
182 {
183 	struct br2684_vcc *brvcc = BR2684_VCC(vcc);
184 	struct net_device *net_dev = skb->dev;
185 
186 	pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev);
187 	brvcc->old_pop(vcc, skb);
188 
189 	if (!net_dev)
190 		return;
191 
192 	if (atm_may_send(vcc, 0))
193 		netif_wake_queue(net_dev);
194 
195 }
196 /*
197  * Send a packet out a particular vcc.  Not to useful right now, but paves
198  * the way for multiple vcc's per itf.  Returns true if we can send,
199  * otherwise false
200  */
201 static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
202 			   struct br2684_vcc *brvcc)
203 {
204 	struct br2684_dev *brdev = BRPRIV(dev);
205 	struct atm_vcc *atmvcc;
206 	int minheadroom = (brvcc->encaps == e_llc) ?
207 		((brdev->payload == p_bridged) ?
208 			sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) :
209 		((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0);
210 
211 	if (skb_headroom(skb) < minheadroom) {
212 		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
213 		brvcc->copies_needed++;
214 		dev_kfree_skb(skb);
215 		if (skb2 == NULL) {
216 			brvcc->copies_failed++;
217 			return 0;
218 		}
219 		skb = skb2;
220 	}
221 
222 	if (brvcc->encaps == e_llc) {
223 		if (brdev->payload == p_bridged) {
224 			skb_push(skb, sizeof(llc_oui_pid_pad));
225 			skb_copy_to_linear_data(skb, llc_oui_pid_pad,
226 						sizeof(llc_oui_pid_pad));
227 		} else if (brdev->payload == p_routed) {
228 			unsigned short prot = ntohs(skb->protocol);
229 
230 			skb_push(skb, sizeof(llc_oui_ipv4));
231 			switch (prot) {
232 			case ETH_P_IP:
233 				skb_copy_to_linear_data(skb, llc_oui_ipv4,
234 							sizeof(llc_oui_ipv4));
235 				break;
236 			case ETH_P_IPV6:
237 				skb_copy_to_linear_data(skb, llc_oui_ipv6,
238 							sizeof(llc_oui_ipv6));
239 				break;
240 			default:
241 				dev_kfree_skb(skb);
242 				return 0;
243 			}
244 		}
245 	} else { /* e_vc */
246 		if (brdev->payload == p_bridged) {
247 			skb_push(skb, 2);
248 			memset(skb->data, 0, 2);
249 		}
250 	}
251 	skb_debug(skb);
252 
253 	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
254 	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
255 	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
256 	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
257 	dev->stats.tx_packets++;
258 	dev->stats.tx_bytes += skb->len;
259 	atmvcc->send(atmvcc, skb);
260 
261 	if (!atm_may_send(atmvcc, 0)) {
262 		netif_stop_queue(brvcc->device);
263 		/*check for race with br2684_pop*/
264 		if (atm_may_send(atmvcc, 0))
265 			netif_start_queue(brvcc->device);
266 	}
267 
268 	return 1;
269 }
270 
271 static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
272 						   const struct br2684_dev *brdev)
273 {
274 	return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);	/* 1 vcc/dev right now */
275 }
276 
277 static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
278 				     struct net_device *dev)
279 {
280 	struct br2684_dev *brdev = BRPRIV(dev);
281 	struct br2684_vcc *brvcc;
282 
283 	pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
284 	read_lock(&devs_lock);
285 	brvcc = pick_outgoing_vcc(skb, brdev);
286 	if (brvcc == NULL) {
287 		pr_debug("no vcc attached to dev %s\n", dev->name);
288 		dev->stats.tx_errors++;
289 		dev->stats.tx_carrier_errors++;
290 		/* netif_stop_queue(dev); */
291 		dev_kfree_skb(skb);
292 		read_unlock(&devs_lock);
293 		return NETDEV_TX_OK;
294 	}
295 	if (!br2684_xmit_vcc(skb, dev, brvcc)) {
296 		/*
297 		 * We should probably use netif_*_queue() here, but that
298 		 * involves added complication.  We need to walk before
299 		 * we can run.
300 		 *
301 		 * Don't free here! this pointer might be no longer valid!
302 		 */
303 		dev->stats.tx_errors++;
304 		dev->stats.tx_fifo_errors++;
305 	}
306 	read_unlock(&devs_lock);
307 	return NETDEV_TX_OK;
308 }
309 
310 /*
311  * We remember when the MAC gets set, so we don't override it later with
312  * the ESI of the ATM card of the first VC
313  */
314 static int br2684_mac_addr(struct net_device *dev, void *p)
315 {
316 	int err = eth_mac_addr(dev, p);
317 	if (!err)
318 		BRPRIV(dev)->mac_was_set = 1;
319 	return err;
320 }
321 
322 #ifdef CONFIG_ATM_BR2684_IPFILTER
323 /* this IOCTL is experimental. */
324 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
325 {
326 	struct br2684_vcc *brvcc;
327 	struct br2684_filter_set fs;
328 
329 	if (copy_from_user(&fs, arg, sizeof fs))
330 		return -EFAULT;
331 	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
332 		/*
333 		 * This is really a per-vcc thing, but we can also search
334 		 * by device.
335 		 */
336 		struct br2684_dev *brdev;
337 		read_lock(&devs_lock);
338 		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
339 		if (brdev == NULL || list_empty(&brdev->brvccs) ||
340 		    brdev->brvccs.next != brdev->brvccs.prev)	/* >1 VCC */
341 			brvcc = NULL;
342 		else
343 			brvcc = list_entry_brvcc(brdev->brvccs.next);
344 		read_unlock(&devs_lock);
345 		if (brvcc == NULL)
346 			return -ESRCH;
347 	} else
348 		brvcc = BR2684_VCC(atmvcc);
349 	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
350 	return 0;
351 }
352 
353 /* Returns 1 if packet should be dropped */
354 static inline int
355 packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
356 {
357 	if (brvcc->filter.netmask == 0)
358 		return 0;	/* no filter in place */
359 	if (type == htons(ETH_P_IP) &&
360 	    (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
361 	     netmask) == brvcc->filter.prefix)
362 		return 0;
363 	if (type == htons(ETH_P_ARP))
364 		return 0;
365 	/*
366 	 * TODO: we should probably filter ARPs too.. don't want to have
367 	 * them returning values that don't make sense, or is that ok?
368 	 */
369 	return 1;		/* drop */
370 }
371 #endif /* CONFIG_ATM_BR2684_IPFILTER */
372 
373 static void br2684_close_vcc(struct br2684_vcc *brvcc)
374 {
375 	pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
376 	write_lock_irq(&devs_lock);
377 	list_del(&brvcc->brvccs);
378 	write_unlock_irq(&devs_lock);
379 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
380 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
381 	kfree(brvcc);
382 	module_put(THIS_MODULE);
383 }
384 
385 /* when AAL5 PDU comes in: */
386 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
387 {
388 	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
389 	struct net_device *net_dev = brvcc->device;
390 	struct br2684_dev *brdev = BRPRIV(net_dev);
391 
392 	pr_debug("\n");
393 
394 	if (unlikely(skb == NULL)) {
395 		/* skb==NULL means VCC is being destroyed */
396 		br2684_close_vcc(brvcc);
397 		if (list_empty(&brdev->brvccs)) {
398 			write_lock_irq(&devs_lock);
399 			list_del(&brdev->br2684_devs);
400 			write_unlock_irq(&devs_lock);
401 			unregister_netdev(net_dev);
402 			free_netdev(net_dev);
403 		}
404 		return;
405 	}
406 
407 	skb_debug(skb);
408 	atm_return(atmvcc, skb->truesize);
409 	pr_debug("skb from brdev %p\n", brdev);
410 	if (brvcc->encaps == e_llc) {
411 
412 		if (skb->len > 7 && skb->data[7] == 0x01)
413 			__skb_trim(skb, skb->len - 4);
414 
415 		/* accept packets that have "ipv[46]" in the snap header */
416 		if ((skb->len >= (sizeof(llc_oui_ipv4))) &&
417 		    (memcmp(skb->data, llc_oui_ipv4,
418 			    sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
419 			if (memcmp(skb->data + 6, ethertype_ipv6,
420 				   sizeof(ethertype_ipv6)) == 0)
421 				skb->protocol = htons(ETH_P_IPV6);
422 			else if (memcmp(skb->data + 6, ethertype_ipv4,
423 					sizeof(ethertype_ipv4)) == 0)
424 				skb->protocol = htons(ETH_P_IP);
425 			else
426 				goto error;
427 			skb_pull(skb, sizeof(llc_oui_ipv4));
428 			skb_reset_network_header(skb);
429 			skb->pkt_type = PACKET_HOST;
430 		/*
431 		 * Let us waste some time for checking the encapsulation.
432 		 * Note, that only 7 char is checked so frames with a valid FCS
433 		 * are also accepted (but FCS is not checked of course).
434 		 */
435 		} else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
436 			   (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
437 			skb_pull(skb, sizeof(llc_oui_pid_pad));
438 			skb->protocol = eth_type_trans(skb, net_dev);
439 		} else
440 			goto error;
441 
442 	} else { /* e_vc */
443 		if (brdev->payload == p_routed) {
444 			struct iphdr *iph;
445 
446 			skb_reset_network_header(skb);
447 			iph = ip_hdr(skb);
448 			if (iph->version == 4)
449 				skb->protocol = htons(ETH_P_IP);
450 			else if (iph->version == 6)
451 				skb->protocol = htons(ETH_P_IPV6);
452 			else
453 				goto error;
454 			skb->pkt_type = PACKET_HOST;
455 		} else { /* p_bridged */
456 			/* first 2 chars should be 0 */
457 			if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0)
458 				goto error;
459 			skb_pull(skb, BR2684_PAD_LEN);
460 			skb->protocol = eth_type_trans(skb, net_dev);
461 		}
462 	}
463 
464 #ifdef CONFIG_ATM_BR2684_IPFILTER
465 	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
466 		goto dropped;
467 #endif /* CONFIG_ATM_BR2684_IPFILTER */
468 	skb->dev = net_dev;
469 	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
470 	pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
471 	skb_debug(skb);
472 	/* sigh, interface is down? */
473 	if (unlikely(!(net_dev->flags & IFF_UP)))
474 		goto dropped;
475 	net_dev->stats.rx_packets++;
476 	net_dev->stats.rx_bytes += skb->len;
477 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
478 	netif_rx(skb);
479 	return;
480 
481 dropped:
482 	net_dev->stats.rx_dropped++;
483 	goto free_skb;
484 error:
485 	net_dev->stats.rx_errors++;
486 free_skb:
487 	dev_kfree_skb(skb);
488 }
489 
490 /*
491  * Assign a vcc to a dev
492  * Note: we do not have explicit unassign, but look at _push()
493  */
494 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
495 {
496 	struct br2684_vcc *brvcc;
497 	struct br2684_dev *brdev;
498 	struct net_device *net_dev;
499 	struct atm_backend_br2684 be;
500 	int err;
501 
502 	if (copy_from_user(&be, arg, sizeof be))
503 		return -EFAULT;
504 	brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
505 	if (!brvcc)
506 		return -ENOMEM;
507 	write_lock_irq(&devs_lock);
508 	net_dev = br2684_find_dev(&be.ifspec);
509 	if (net_dev == NULL) {
510 		pr_err("tried to attach to non-existent device\n");
511 		err = -ENXIO;
512 		goto error;
513 	}
514 	brdev = BRPRIV(net_dev);
515 	if (atmvcc->push == NULL) {
516 		err = -EBADFD;
517 		goto error;
518 	}
519 	if (!list_empty(&brdev->brvccs)) {
520 		/* Only 1 VCC/dev right now */
521 		err = -EEXIST;
522 		goto error;
523 	}
524 	if (be.fcs_in != BR2684_FCSIN_NO ||
525 	    be.fcs_out != BR2684_FCSOUT_NO ||
526 	    be.fcs_auto || be.has_vpiid || be.send_padding ||
527 	    (be.encaps != BR2684_ENCAPS_VC &&
528 	     be.encaps != BR2684_ENCAPS_LLC) ||
529 	    be.min_size != 0) {
530 		err = -EINVAL;
531 		goto error;
532 	}
533 	pr_debug("vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps, brvcc);
534 	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
535 		unsigned char *esi = atmvcc->dev->esi;
536 		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
537 			memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
538 		else
539 			net_dev->dev_addr[2] = 1;
540 	}
541 	list_add(&brvcc->brvccs, &brdev->brvccs);
542 	write_unlock_irq(&devs_lock);
543 	brvcc->device = net_dev;
544 	brvcc->atmvcc = atmvcc;
545 	atmvcc->user_back = brvcc;
546 	brvcc->encaps = (enum br2684_encaps)be.encaps;
547 	brvcc->old_push = atmvcc->push;
548 	brvcc->old_pop = atmvcc->pop;
549 	barrier();
550 	atmvcc->push = br2684_push;
551 	atmvcc->pop = br2684_pop;
552 
553 	/* initialize netdev carrier state */
554 	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
555 		netif_carrier_off(net_dev);
556 	else
557 		netif_carrier_on(net_dev);
558 
559 	__module_get(THIS_MODULE);
560 
561 	/* re-process everything received between connection setup and
562 	   backend setup */
563 	vcc_process_recv_queue(atmvcc);
564 	return 0;
565 
566 error:
567 	write_unlock_irq(&devs_lock);
568 	kfree(brvcc);
569 	return err;
570 }
571 
572 static const struct net_device_ops br2684_netdev_ops = {
573 	.ndo_start_xmit 	= br2684_start_xmit,
574 	.ndo_set_mac_address	= br2684_mac_addr,
575 	.ndo_change_mtu		= eth_change_mtu,
576 	.ndo_validate_addr	= eth_validate_addr,
577 };
578 
579 static const struct net_device_ops br2684_netdev_ops_routed = {
580 	.ndo_start_xmit 	= br2684_start_xmit,
581 	.ndo_set_mac_address	= br2684_mac_addr,
582 	.ndo_change_mtu		= eth_change_mtu
583 };
584 
585 static void br2684_setup(struct net_device *netdev)
586 {
587 	struct br2684_dev *brdev = BRPRIV(netdev);
588 
589 	ether_setup(netdev);
590 	netdev->hard_header_len += sizeof(llc_oui_pid_pad); /* worst case */
591 	brdev->net_dev = netdev;
592 
593 	netdev->netdev_ops = &br2684_netdev_ops;
594 
595 	INIT_LIST_HEAD(&brdev->brvccs);
596 }
597 
598 static void br2684_setup_routed(struct net_device *netdev)
599 {
600 	struct br2684_dev *brdev = BRPRIV(netdev);
601 
602 	brdev->net_dev = netdev;
603 	netdev->hard_header_len = sizeof(llc_oui_ipv4); /* worst case */
604 	netdev->netdev_ops = &br2684_netdev_ops_routed;
605 	netdev->addr_len = 0;
606 	netdev->mtu = 1500;
607 	netdev->type = ARPHRD_PPP;
608 	netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
609 	netdev->tx_queue_len = 100;
610 	INIT_LIST_HEAD(&brdev->brvccs);
611 }
612 
613 static int br2684_create(void __user *arg)
614 {
615 	int err;
616 	struct net_device *netdev;
617 	struct br2684_dev *brdev;
618 	struct atm_newif_br2684 ni;
619 	enum br2684_payload payload;
620 
621 	pr_debug("\n");
622 
623 	if (copy_from_user(&ni, arg, sizeof ni))
624 		return -EFAULT;
625 
626 	if (ni.media & BR2684_FLAG_ROUTED)
627 		payload = p_routed;
628 	else
629 		payload = p_bridged;
630 	ni.media &= 0xffff;	/* strip flags */
631 
632 	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500)
633 		return -EINVAL;
634 
635 	netdev = alloc_netdev(sizeof(struct br2684_dev),
636 			      ni.ifname[0] ? ni.ifname : "nas%d",
637 			      (payload == p_routed) ?
638 			      br2684_setup_routed : br2684_setup);
639 	if (!netdev)
640 		return -ENOMEM;
641 
642 	brdev = BRPRIV(netdev);
643 
644 	pr_debug("registered netdev %s\n", netdev->name);
645 	/* open, stop, do_ioctl ? */
646 	err = register_netdev(netdev);
647 	if (err < 0) {
648 		pr_err("register_netdev failed\n");
649 		free_netdev(netdev);
650 		return err;
651 	}
652 
653 	write_lock_irq(&devs_lock);
654 
655 	brdev->payload = payload;
656 
657 	if (list_empty(&br2684_devs)) {
658 		/* 1st br2684 device */
659 		brdev->number = 1;
660 	} else
661 		brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
662 
663 	list_add_tail(&brdev->br2684_devs, &br2684_devs);
664 	write_unlock_irq(&devs_lock);
665 	return 0;
666 }
667 
668 /*
669  * This handles ioctls actually performed on our vcc - we must return
670  * -ENOIOCTLCMD for any unrecognized ioctl
671  */
672 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
673 			unsigned long arg)
674 {
675 	struct atm_vcc *atmvcc = ATM_SD(sock);
676 	void __user *argp = (void __user *)arg;
677 	atm_backend_t b;
678 
679 	int err;
680 	switch (cmd) {
681 	case ATM_SETBACKEND:
682 	case ATM_NEWBACKENDIF:
683 		err = get_user(b, (atm_backend_t __user *) argp);
684 		if (err)
685 			return -EFAULT;
686 		if (b != ATM_BACKEND_BR2684)
687 			return -ENOIOCTLCMD;
688 		if (!capable(CAP_NET_ADMIN))
689 			return -EPERM;
690 		if (cmd == ATM_SETBACKEND)
691 			return br2684_regvcc(atmvcc, argp);
692 		else
693 			return br2684_create(argp);
694 #ifdef CONFIG_ATM_BR2684_IPFILTER
695 	case BR2684_SETFILT:
696 		if (atmvcc->push != br2684_push)
697 			return -ENOIOCTLCMD;
698 		if (!capable(CAP_NET_ADMIN))
699 			return -EPERM;
700 		err = br2684_setfilt(atmvcc, argp);
701 
702 		return err;
703 #endif /* CONFIG_ATM_BR2684_IPFILTER */
704 	}
705 	return -ENOIOCTLCMD;
706 }
707 
708 static struct atm_ioctl br2684_ioctl_ops = {
709 	.owner = THIS_MODULE,
710 	.ioctl = br2684_ioctl,
711 };
712 
713 #ifdef CONFIG_PROC_FS
714 static void *br2684_seq_start(struct seq_file *seq, loff_t * pos)
715 	__acquires(devs_lock)
716 {
717 	read_lock(&devs_lock);
718 	return seq_list_start(&br2684_devs, *pos);
719 }
720 
721 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t * pos)
722 {
723 	return seq_list_next(v, &br2684_devs, pos);
724 }
725 
726 static void br2684_seq_stop(struct seq_file *seq, void *v)
727 	__releases(devs_lock)
728 {
729 	read_unlock(&devs_lock);
730 }
731 
732 static int br2684_seq_show(struct seq_file *seq, void *v)
733 {
734 	const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
735 						    br2684_devs);
736 	const struct net_device *net_dev = brdev->net_dev;
737 	const struct br2684_vcc *brvcc;
738 
739 	seq_printf(seq, "dev %.16s: num=%d, mac=%pM (%s)\n",
740 		   net_dev->name,
741 		   brdev->number,
742 		   net_dev->dev_addr,
743 		   brdev->mac_was_set ? "set" : "auto");
744 
745 	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
746 		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
747 			   ", failed copies %u/%u"
748 			   "\n", brvcc->atmvcc->dev->number,
749 			   brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
750 			   (brvcc->encaps == e_llc) ? "LLC" : "VC",
751 			   (brdev->payload == p_bridged) ? "bridged" : "routed",
752 			   brvcc->copies_failed, brvcc->copies_needed);
753 #ifdef CONFIG_ATM_BR2684_IPFILTER
754 #define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
755 #define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
756 		if (brvcc->filter.netmask != 0)
757 			seq_printf(seq, "    filter=%d.%d.%d.%d/"
758 				   "%d.%d.%d.%d\n", bs(prefix), bs(netmask));
759 #undef bs
760 #undef b1
761 #endif /* CONFIG_ATM_BR2684_IPFILTER */
762 	}
763 	return 0;
764 }
765 
766 static const struct seq_operations br2684_seq_ops = {
767 	.start = br2684_seq_start,
768 	.next = br2684_seq_next,
769 	.stop = br2684_seq_stop,
770 	.show = br2684_seq_show,
771 };
772 
773 static int br2684_proc_open(struct inode *inode, struct file *file)
774 {
775 	return seq_open(file, &br2684_seq_ops);
776 }
777 
778 static const struct file_operations br2684_proc_ops = {
779 	.owner = THIS_MODULE,
780 	.open = br2684_proc_open,
781 	.read = seq_read,
782 	.llseek = seq_lseek,
783 	.release = seq_release,
784 };
785 
786 extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
787 #endif /* CONFIG_PROC_FS */
788 
789 static int __init br2684_init(void)
790 {
791 #ifdef CONFIG_PROC_FS
792 	struct proc_dir_entry *p;
793 	p = proc_create("br2684", 0, atm_proc_root, &br2684_proc_ops);
794 	if (p == NULL)
795 		return -ENOMEM;
796 #endif
797 	register_atm_ioctl(&br2684_ioctl_ops);
798 	register_atmdevice_notifier(&atm_dev_notifier);
799 	return 0;
800 }
801 
802 static void __exit br2684_exit(void)
803 {
804 	struct net_device *net_dev;
805 	struct br2684_dev *brdev;
806 	struct br2684_vcc *brvcc;
807 	deregister_atm_ioctl(&br2684_ioctl_ops);
808 
809 #ifdef CONFIG_PROC_FS
810 	remove_proc_entry("br2684", atm_proc_root);
811 #endif
812 
813 
814 	unregister_atmdevice_notifier(&atm_dev_notifier);
815 
816 	while (!list_empty(&br2684_devs)) {
817 		net_dev = list_entry_brdev(br2684_devs.next);
818 		brdev = BRPRIV(net_dev);
819 		while (!list_empty(&brdev->brvccs)) {
820 			brvcc = list_entry_brvcc(brdev->brvccs.next);
821 			br2684_close_vcc(brvcc);
822 		}
823 
824 		list_del(&brdev->br2684_devs);
825 		unregister_netdev(net_dev);
826 		free_netdev(net_dev);
827 	}
828 }
829 
830 module_init(br2684_init);
831 module_exit(br2684_exit);
832 
833 MODULE_AUTHOR("Marcell GAL");
834 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
835 MODULE_LICENSE("GPL");
836