xref: /openbmc/linux/net/atm/br2684.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 /*
28  * Define this to use a version of the code which interacts with the higher
29  * layers in a more intellegent way, by always reserving enough space for
30  * our header at the begining of the packet.  However, there may still be
31  * some problems with programs like tcpdump.  In 2.5 we'll sort out what
32  * we need to do to get this perfect.  For now we just will copy the packet
33  * if we need space for the header
34  */
35 /* #define FASTER_VERSION */
36 
37 #ifdef DEBUG
38 #define DPRINTK(format, args...) printk(KERN_DEBUG "br2684: " format, ##args)
39 #else
40 #define DPRINTK(format, args...)
41 #endif
42 
43 #ifdef SKB_DEBUG
44 static void skb_debug(const struct sk_buff *skb)
45 {
46 #define NUM2PRINT 50
47 	char buf[NUM2PRINT * 3 + 1];	/* 3 chars per byte */
48 	int i = 0;
49 	for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
50 		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
51 	}
52 	printk(KERN_DEBUG "br2684: skb: %s\n", buf);
53 }
54 #else
55 #define skb_debug(skb)	do {} while (0)
56 #endif
57 
58 static unsigned char llc_oui_pid_pad[] =
59     { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
60 #define PADLEN	(2)
61 
62 enum br2684_encaps {
63 	e_vc  = BR2684_ENCAPS_VC,
64 	e_llc = BR2684_ENCAPS_LLC,
65 };
66 
67 struct br2684_vcc {
68 	struct atm_vcc  *atmvcc;
69 	struct net_device *device;
70 	/* keep old push,pop functions for chaining */
71 	void (*old_push)(struct atm_vcc *vcc,struct sk_buff *skb);
72 	/* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
73 	enum br2684_encaps encaps;
74 	struct list_head brvccs;
75 #ifdef CONFIG_ATM_BR2684_IPFILTER
76 	struct br2684_filter filter;
77 #endif /* CONFIG_ATM_BR2684_IPFILTER */
78 #ifndef FASTER_VERSION
79 	unsigned copies_needed, copies_failed;
80 #endif /* FASTER_VERSION */
81 };
82 
83 struct br2684_dev {
84 	struct net_device *net_dev;
85 	struct list_head br2684_devs;
86 	int number;
87 	struct list_head brvccs; /* one device <=> one vcc (before xmas) */
88 	struct net_device_stats stats;
89 	int mac_was_set;
90 };
91 
92 /*
93  * This lock should be held for writing any time the list of devices or
94  * their attached vcc's could be altered.  It should be held for reading
95  * any time these are being queried.  Note that we sometimes need to
96  * do read-locking under interrupt context, so write locking must block
97  * the current CPU's interrupts
98  */
99 static DEFINE_RWLOCK(devs_lock);
100 
101 static LIST_HEAD(br2684_devs);
102 
103 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
104 {
105 	return (struct br2684_dev *) net_dev->priv;
106 }
107 
108 static inline struct net_device *list_entry_brdev(const struct list_head *le)
109 {
110 	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
111 }
112 
113 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
114 {
115 	return (struct br2684_vcc *) (atmvcc->user_back);
116 }
117 
118 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
119 {
120 	return list_entry(le, struct br2684_vcc, brvccs);
121 }
122 
123 /* Caller should hold read_lock(&devs_lock) */
124 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
125 {
126 	struct list_head *lh;
127 	struct net_device *net_dev;
128 	switch (s->method) {
129 	case BR2684_FIND_BYNUM:
130 		list_for_each(lh, &br2684_devs) {
131 			net_dev = list_entry_brdev(lh);
132 			if (BRPRIV(net_dev)->number == s->spec.devnum)
133 				return net_dev;
134 		}
135 		break;
136 	case BR2684_FIND_BYIFNAME:
137 		list_for_each(lh, &br2684_devs) {
138 			net_dev = list_entry_brdev(lh);
139 			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
140 				return net_dev;
141 		}
142 		break;
143 	}
144 	return NULL;
145 }
146 
147 /*
148  * Send a packet out a particular vcc.  Not to useful right now, but paves
149  * the way for multiple vcc's per itf.  Returns true if we can send,
150  * otherwise false
151  */
152 static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
153 	struct br2684_vcc *brvcc)
154 {
155 	struct atm_vcc *atmvcc;
156 #ifdef FASTER_VERSION
157 	if (brvcc->encaps == e_llc)
158 		memcpy(skb_push(skb, 8), llc_oui_pid_pad, 8);
159 	/* last 2 bytes of llc_oui_pid_pad are managed by header routines;
160 	   yes, you got it: 8 + 2 = sizeof(llc_oui_pid_pad)
161 	 */
162 #else
163 	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
164 	if (skb_headroom(skb) < minheadroom) {
165 		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
166 		brvcc->copies_needed++;
167 		dev_kfree_skb(skb);
168 		if (skb2 == NULL) {
169 			brvcc->copies_failed++;
170 			return 0;
171 		}
172 		skb = skb2;
173 	}
174 	skb_push(skb, minheadroom);
175 	if (brvcc->encaps == e_llc)
176 		skb_copy_to_linear_data(skb, llc_oui_pid_pad, 10);
177 	else
178 		memset(skb->data, 0, 2);
179 #endif /* FASTER_VERSION */
180 	skb_debug(skb);
181 
182 	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
183 	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
184 	if (!atm_may_send(atmvcc, skb->truesize)) {
185 		/* we free this here for now, because we cannot know in a higher
186 			layer whether the skb point it supplied wasn't freed yet.
187 			now, it always is.
188 		*/
189 		dev_kfree_skb(skb);
190 		return 0;
191 		}
192 	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
193 	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
194 	brdev->stats.tx_packets++;
195 	brdev->stats.tx_bytes += skb->len;
196 	atmvcc->send(atmvcc, skb);
197 	return 1;
198 }
199 
200 static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb,
201 	struct br2684_dev *brdev)
202 {
203 	return list_empty(&brdev->brvccs) ? NULL :
204 	    list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */
205 }
206 
207 static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
208 {
209 	struct br2684_dev *brdev = BRPRIV(dev);
210 	struct br2684_vcc *brvcc;
211 
212 	DPRINTK("br2684_start_xmit, skb->dst=%p\n", skb->dst);
213 	read_lock(&devs_lock);
214 	brvcc = pick_outgoing_vcc(skb, brdev);
215 	if (brvcc == NULL) {
216 		DPRINTK("no vcc attached to dev %s\n", dev->name);
217 		brdev->stats.tx_errors++;
218 		brdev->stats.tx_carrier_errors++;
219 		/* netif_stop_queue(dev); */
220 		dev_kfree_skb(skb);
221 		read_unlock(&devs_lock);
222 		return 0;
223 	}
224 	if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
225 		/*
226 		 * We should probably use netif_*_queue() here, but that
227 		 * involves added complication.  We need to walk before
228 		 * we can run
229 		 */
230 		/* don't free here! this pointer might be no longer valid!
231 		dev_kfree_skb(skb);
232 		*/
233 		brdev->stats.tx_errors++;
234 		brdev->stats.tx_fifo_errors++;
235 	}
236 	read_unlock(&devs_lock);
237 	return 0;
238 }
239 
240 static struct net_device_stats *br2684_get_stats(struct net_device *dev)
241 {
242 	DPRINTK("br2684_get_stats\n");
243 	return &BRPRIV(dev)->stats;
244 }
245 
246 #ifdef FASTER_VERSION
247 /*
248  * These mirror eth_header and eth_header_cache.  They are not usually
249  * exported for use in modules, so we grab them from net_device
250  * after ether_setup() is done with it.  Bit of a hack.
251  */
252 static int (*my_eth_header)(struct sk_buff *, struct net_device *,
253 	unsigned short, void *, void *, unsigned);
254 static int (*my_eth_header_cache)(struct neighbour *, struct hh_cache *);
255 
256 static int
257 br2684_header(struct sk_buff *skb, struct net_device *dev,
258 	      unsigned short type, void *daddr, void *saddr, unsigned len)
259 {
260 	u16 *pad_before_eth;
261 	int t = my_eth_header(skb, dev, type, daddr, saddr, len);
262 	if (t > 0) {
263 		pad_before_eth = (u16 *) skb_push(skb, 2);
264 		*pad_before_eth = 0;
265 		return dev->hard_header_len;	/* or return 16; ? */
266 	} else
267 		return t;
268 }
269 
270 static int
271 br2684_header_cache(struct neighbour *neigh, struct hh_cache *hh)
272 {
273 /* hh_data is 16 bytes long. if encaps is ether-llc we need 24, so
274 xmit will add the additional header part in that case */
275 	u16 *pad_before_eth = (u16 *)(hh->hh_data);
276 	int t = my_eth_header_cache(neigh, hh);
277 	DPRINTK("br2684_header_cache, neigh=%p, hh_cache=%p\n", neigh, hh);
278 	if (t < 0)
279 		return t;
280 	else {
281 		*pad_before_eth = 0;
282 		hh->hh_len = PADLEN + ETH_HLEN;
283 	}
284 	return 0;
285 }
286 
287 /*
288  * This is similar to eth_type_trans, which cannot be used because of
289  * our dev->hard_header_len
290  */
291 static inline __be16 br_type_trans(struct sk_buff *skb, struct net_device *dev)
292 {
293 	struct ethhdr *eth;
294 	unsigned char *rawp;
295 	eth = eth_hdr(skb);
296 
297 	if (is_multicast_ether_addr(eth->h_dest)) {
298 		if (!compare_ether_addr(eth->h_dest, dev->broadcast))
299 			skb->pkt_type = PACKET_BROADCAST;
300 		else
301 			skb->pkt_type = PACKET_MULTICAST;
302 	}
303 
304 	else if (compare_ether_addr(eth->h_dest, dev->dev_addr))
305 		skb->pkt_type = PACKET_OTHERHOST;
306 
307 	if (ntohs(eth->h_proto) >= 1536)
308 		return eth->h_proto;
309 
310 	rawp = skb->data;
311 
312 	/*
313 	 * This is a magic hack to spot IPX packets. Older Novell breaks
314 	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
315 	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
316 	 * won't work for fault tolerant netware but does for the rest.
317 	 */
318 	if (*(unsigned short *) rawp == 0xFFFF)
319 		return htons(ETH_P_802_3);
320 
321 	/*
322 	 * Real 802.2 LLC
323 	 */
324 	return htons(ETH_P_802_2);
325 }
326 #endif /* FASTER_VERSION */
327 
328 /*
329  * We remember when the MAC gets set, so we don't override it later with
330  * the ESI of the ATM card of the first VC
331  */
332 static int (*my_eth_mac_addr)(struct net_device *, void *);
333 static int br2684_mac_addr(struct net_device *dev, void *p)
334 {
335 	int err = my_eth_mac_addr(dev, p);
336 	if (!err)
337 		BRPRIV(dev)->mac_was_set = 1;
338 	return err;
339 }
340 
341 #ifdef CONFIG_ATM_BR2684_IPFILTER
342 /* this IOCTL is experimental. */
343 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user *arg)
344 {
345 	struct br2684_vcc *brvcc;
346 	struct br2684_filter_set fs;
347 
348 	if (copy_from_user(&fs, arg, sizeof fs))
349 		return -EFAULT;
350 	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
351 		/*
352 		 * This is really a per-vcc thing, but we can also search
353 		 * by device
354 		 */
355 		struct br2684_dev *brdev;
356 		read_lock(&devs_lock);
357 		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
358 		if (brdev == NULL || list_empty(&brdev->brvccs) ||
359 		    brdev->brvccs.next != brdev->brvccs.prev)  /* >1 VCC */
360 			brvcc = NULL;
361 		else
362 			brvcc = list_entry_brvcc(brdev->brvccs.next);
363 		read_unlock(&devs_lock);
364 		if (brvcc == NULL)
365 			return -ESRCH;
366 	} else
367 		brvcc = BR2684_VCC(atmvcc);
368 	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
369 	return 0;
370 }
371 
372 /* Returns 1 if packet should be dropped */
373 static inline int
374 packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
375 {
376 	if (brvcc->filter.netmask == 0)
377 		return 0;			/* no filter in place */
378 	if (type == htons(ETH_P_IP) &&
379 	    (((struct iphdr *) (skb->data))->daddr & brvcc->filter.
380 	     netmask) == brvcc->filter.prefix)
381 		return 0;
382 	if (type == htons(ETH_P_ARP))
383 		return 0;
384 	/* TODO: we should probably filter ARPs too.. don't want to have
385 	 *   them returning values that don't make sense, or is that ok?
386 	 */
387 	return 1;		/* drop */
388 }
389 #endif /* CONFIG_ATM_BR2684_IPFILTER */
390 
391 static void br2684_close_vcc(struct br2684_vcc *brvcc)
392 {
393 	DPRINTK("removing VCC %p from dev %p\n", brvcc, brvcc->device);
394 	write_lock_irq(&devs_lock);
395 	list_del(&brvcc->brvccs);
396 	write_unlock_irq(&devs_lock);
397 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
398 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
399 	kfree(brvcc);
400 	module_put(THIS_MODULE);
401 }
402 
403 /* when AAL5 PDU comes in: */
404 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
405 {
406 	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
407 	struct net_device *net_dev = brvcc->device;
408 	struct br2684_dev *brdev = BRPRIV(net_dev);
409 	int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
410 
411 	DPRINTK("br2684_push\n");
412 
413 	if (unlikely(skb == NULL)) {
414 		/* skb==NULL means VCC is being destroyed */
415 		br2684_close_vcc(brvcc);
416 		if (list_empty(&brdev->brvccs)) {
417 			read_lock(&devs_lock);
418 			list_del(&brdev->br2684_devs);
419 			read_unlock(&devs_lock);
420 			unregister_netdev(net_dev);
421 			free_netdev(net_dev);
422 		}
423 		return;
424 	}
425 
426 	skb_debug(skb);
427 	atm_return(atmvcc, skb->truesize);
428 	DPRINTK("skb from brdev %p\n", brdev);
429 	if (brvcc->encaps == e_llc) {
430 		/* let us waste some time for checking the encapsulation.
431 		   Note, that only 7 char is checked so frames with a valid FCS
432 		   are also accepted (but FCS is not checked of course) */
433 		if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
434 			brdev->stats.rx_errors++;
435 			dev_kfree_skb(skb);
436 			return;
437 		}
438 
439 		/* Strip FCS if present */
440 		if (skb->len > 7 && skb->data[7] == 0x01)
441 			__skb_trim(skb, skb->len - 4);
442 	} else {
443 		plen = PADLEN + ETH_HLEN;	/* pad, dstmac,srcmac, ethtype */
444 		/* first 2 chars should be 0 */
445 		if (*((u16 *) (skb->data)) != 0) {
446 			brdev->stats.rx_errors++;
447 			dev_kfree_skb(skb);
448 			return;
449 		}
450 	}
451 	if (skb->len < plen) {
452 		brdev->stats.rx_errors++;
453 		dev_kfree_skb(skb);	/* dev_ not needed? */
454 		return;
455 	}
456 
457 #ifdef FASTER_VERSION
458 	/* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier,
459 	   than should be. What else should I set? */
460 	skb_pull(skb, plen);
461 	skb_set_mac_header(skb, -ETH_HLEN);
462 	skb->pkt_type = PACKET_HOST;
463 #ifdef CONFIG_BR2684_FAST_TRANS
464 	skb->protocol = ((u16 *) skb->data)[-1];
465 #else				/* some protocols might require this: */
466 	skb->protocol = br_type_trans(skb, net_dev);
467 #endif /* CONFIG_BR2684_FAST_TRANS */
468 #else
469 	skb_pull(skb, plen - ETH_HLEN);
470 	skb->protocol = eth_type_trans(skb, net_dev);
471 #endif /* FASTER_VERSION */
472 #ifdef CONFIG_ATM_BR2684_IPFILTER
473 	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
474 		brdev->stats.rx_dropped++;
475 		dev_kfree_skb(skb);
476 		return;
477 	}
478 #endif /* CONFIG_ATM_BR2684_IPFILTER */
479 	skb->dev = net_dev;
480 	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
481 	DPRINTK("received packet's protocol: %x\n", ntohs(skb->protocol));
482 	skb_debug(skb);
483 	if (unlikely(!(net_dev->flags & IFF_UP))) {
484 		/* sigh, interface is down */
485 		brdev->stats.rx_dropped++;
486 		dev_kfree_skb(skb);
487 		return;
488 	}
489 	brdev->stats.rx_packets++;
490 	brdev->stats.rx_bytes += skb->len;
491 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
492 	netif_rx(skb);
493 }
494 
495 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user *arg)
496 {
497 /* assign a vcc to a dev
498 Note: we do not have explicit unassign, but look at _push()
499 */
500 	int err;
501 	struct br2684_vcc *brvcc;
502 	struct sk_buff *skb;
503 	struct sk_buff_head *rq;
504 	struct br2684_dev *brdev;
505 	struct net_device *net_dev;
506 	struct atm_backend_br2684 be;
507 	unsigned long flags;
508 
509 	if (copy_from_user(&be, arg, sizeof be))
510 		return -EFAULT;
511 	brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
512 	if (!brvcc)
513 		return -ENOMEM;
514 	write_lock_irq(&devs_lock);
515 	net_dev = br2684_find_dev(&be.ifspec);
516 	if (net_dev == NULL) {
517 		printk(KERN_ERR
518 		    "br2684: tried to attach to non-existant device\n");
519 		err = -ENXIO;
520 		goto error;
521 	}
522 	brdev = BRPRIV(net_dev);
523 	if (atmvcc->push == NULL) {
524 		err = -EBADFD;
525 		goto error;
526 	}
527 	if (!list_empty(&brdev->brvccs)) {
528 		/* Only 1 VCC/dev right now */
529 		err = -EEXIST;
530 		goto error;
531 	}
532 	if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
533 	    be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
534 	    BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
535 	    be.min_size != 0) {
536 		err = -EINVAL;
537 		goto error;
538 	}
539 	DPRINTK("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
540 		brvcc);
541 	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
542 		unsigned char *esi = atmvcc->dev->esi;
543 		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
544 			memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
545 		else
546 			net_dev->dev_addr[2] = 1;
547 	}
548 	list_add(&brvcc->brvccs, &brdev->brvccs);
549 	write_unlock_irq(&devs_lock);
550 	brvcc->device = net_dev;
551 	brvcc->atmvcc = atmvcc;
552 	atmvcc->user_back = brvcc;
553 	brvcc->encaps = (enum br2684_encaps) be.encaps;
554 	brvcc->old_push = atmvcc->push;
555 	barrier();
556 	atmvcc->push = br2684_push;
557 
558 	rq = &sk_atm(atmvcc)->sk_receive_queue;
559 
560 	spin_lock_irqsave(&rq->lock, flags);
561 	if (skb_queue_empty(rq)) {
562 		skb = NULL;
563 	} else {
564 		/* NULL terminate the list.  */
565 		rq->prev->next = NULL;
566 		skb = rq->next;
567 	}
568 	rq->prev = rq->next = (struct sk_buff *)rq;
569 	rq->qlen = 0;
570 	spin_unlock_irqrestore(&rq->lock, flags);
571 
572 	while (skb) {
573 		struct sk_buff *next = skb->next;
574 
575 		skb->next = skb->prev = NULL;
576 		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
577 		BRPRIV(skb->dev)->stats.rx_packets--;
578 		br2684_push(atmvcc, skb);
579 
580 		skb = next;
581 	}
582 	__module_get(THIS_MODULE);
583 	return 0;
584     error:
585 	write_unlock_irq(&devs_lock);
586 	kfree(brvcc);
587 	return err;
588 }
589 
590 static void br2684_setup(struct net_device *netdev)
591 {
592 	struct br2684_dev *brdev = BRPRIV(netdev);
593 
594 	ether_setup(netdev);
595 	brdev->net_dev = netdev;
596 
597 #ifdef FASTER_VERSION
598 	my_eth_header = netdev->hard_header;
599 	netdev->hard_header = br2684_header;
600 	my_eth_header_cache = netdev->hard_header_cache;
601 	netdev->hard_header_cache = br2684_header_cache;
602 	netdev->hard_header_len = sizeof(llc_oui_pid_pad) + ETH_HLEN;	/* 10 + 14 */
603 #endif
604 	my_eth_mac_addr = netdev->set_mac_address;
605 	netdev->set_mac_address = br2684_mac_addr;
606 	netdev->hard_start_xmit = br2684_start_xmit;
607 	netdev->get_stats = br2684_get_stats;
608 
609 	INIT_LIST_HEAD(&brdev->brvccs);
610 }
611 
612 static int br2684_create(void __user *arg)
613 {
614 	int err;
615 	struct net_device *netdev;
616 	struct br2684_dev *brdev;
617 	struct atm_newif_br2684 ni;
618 
619 	DPRINTK("br2684_create\n");
620 
621 	if (copy_from_user(&ni, arg, sizeof ni)) {
622 		return -EFAULT;
623 	}
624 	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
625 		return -EINVAL;
626 	}
627 
628 	netdev = alloc_netdev(sizeof(struct br2684_dev),
629 			      ni.ifname[0] ? ni.ifname : "nas%d",
630 			      br2684_setup);
631 	if (!netdev)
632 		return -ENOMEM;
633 
634 	brdev = BRPRIV(netdev);
635 
636 	DPRINTK("registered netdev %s\n", netdev->name);
637 	/* open, stop, do_ioctl ? */
638 	err = register_netdev(netdev);
639 	if (err < 0) {
640 		printk(KERN_ERR "br2684_create: register_netdev failed\n");
641 		free_netdev(netdev);
642 		return err;
643 	}
644 
645 	write_lock_irq(&devs_lock);
646 	brdev->number = list_empty(&br2684_devs) ? 1 :
647 	    BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
648 	list_add_tail(&brdev->br2684_devs, &br2684_devs);
649 	write_unlock_irq(&devs_lock);
650 	return 0;
651 }
652 
653 /*
654  * This handles ioctls actually performed on our vcc - we must return
655  * -ENOIOCTLCMD for any unrecognized ioctl
656  */
657 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
658 	unsigned long arg)
659 {
660 	struct atm_vcc *atmvcc = ATM_SD(sock);
661 	void __user *argp = (void __user *)arg;
662 
663 	int err;
664 	switch(cmd) {
665 	case ATM_SETBACKEND:
666 	case ATM_NEWBACKENDIF: {
667 		atm_backend_t b;
668 		err = get_user(b, (atm_backend_t __user *) argp);
669 		if (err)
670 			return -EFAULT;
671 		if (b != ATM_BACKEND_BR2684)
672 			return -ENOIOCTLCMD;
673 		if (!capable(CAP_NET_ADMIN))
674 			return -EPERM;
675 		if (cmd == ATM_SETBACKEND)
676 			return br2684_regvcc(atmvcc, argp);
677 		else
678 			return br2684_create(argp);
679 		}
680 #ifdef CONFIG_ATM_BR2684_IPFILTER
681 	case BR2684_SETFILT:
682 		if (atmvcc->push != br2684_push)
683 			return -ENOIOCTLCMD;
684 		if (!capable(CAP_NET_ADMIN))
685 			return -EPERM;
686 		err = br2684_setfilt(atmvcc, argp);
687 		return err;
688 #endif /* CONFIG_ATM_BR2684_IPFILTER */
689 	}
690 	return -ENOIOCTLCMD;
691 }
692 
693 static struct atm_ioctl br2684_ioctl_ops = {
694 	.owner	= THIS_MODULE,
695 	.ioctl	= br2684_ioctl,
696 };
697 
698 
699 #ifdef CONFIG_PROC_FS
700 static void *br2684_seq_start(struct seq_file *seq, loff_t *pos)
701 {
702 	loff_t offs = 0;
703 	struct br2684_dev *brd;
704 
705 	read_lock(&devs_lock);
706 
707 	list_for_each_entry(brd, &br2684_devs, br2684_devs) {
708 		if (offs == *pos)
709 			return brd;
710 		++offs;
711 	}
712 	return NULL;
713 }
714 
715 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t *pos)
716 {
717 	struct br2684_dev *brd = v;
718 
719 	++*pos;
720 
721 	brd = list_entry(brd->br2684_devs.next,
722 			 struct br2684_dev, br2684_devs);
723 	return (&brd->br2684_devs != &br2684_devs) ? brd : NULL;
724 }
725 
726 static void br2684_seq_stop(struct seq_file *seq, void *v)
727 {
728 	read_unlock(&devs_lock);
729 }
730 
731 static int br2684_seq_show(struct seq_file *seq, void *v)
732 {
733 	const struct br2684_dev *brdev = v;
734 	const struct net_device *net_dev = brdev->net_dev;
735 	const struct br2684_vcc *brvcc;
736 
737 	seq_printf(seq, "dev %.16s: num=%d, mac=%02X:%02X:"
738 		       "%02X:%02X:%02X:%02X (%s)\n", net_dev->name,
739 		       brdev->number,
740 		       net_dev->dev_addr[0],
741 		       net_dev->dev_addr[1],
742 		       net_dev->dev_addr[2],
743 		       net_dev->dev_addr[3],
744 		       net_dev->dev_addr[4],
745 		       net_dev->dev_addr[5],
746 		       brdev->mac_was_set ? "set" : "auto");
747 
748 	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
749 		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
750 #ifndef FASTER_VERSION
751 				    ", failed copies %u/%u"
752 #endif /* FASTER_VERSION */
753 				    "\n", brvcc->atmvcc->dev->number,
754 				    brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
755 				    (brvcc->encaps == e_llc) ? "LLC" : "VC"
756 #ifndef FASTER_VERSION
757 				    , brvcc->copies_failed
758 				    , brvcc->copies_needed
759 #endif /* FASTER_VERSION */
760 				    );
761 #ifdef CONFIG_ATM_BR2684_IPFILTER
762 #define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
763 #define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
764 			if (brvcc->filter.netmask != 0)
765 				seq_printf(seq, "    filter=%d.%d.%d.%d/"
766 						"%d.%d.%d.%d\n",
767 						bs(prefix), bs(netmask));
768 #undef bs
769 #undef b1
770 #endif /* CONFIG_ATM_BR2684_IPFILTER */
771 	}
772 	return 0;
773 }
774 
775 static struct seq_operations br2684_seq_ops = {
776 	.start = br2684_seq_start,
777 	.next  = br2684_seq_next,
778 	.stop  = br2684_seq_stop,
779 	.show  = br2684_seq_show,
780 };
781 
782 static int br2684_proc_open(struct inode *inode, struct file *file)
783 {
784 	return seq_open(file, &br2684_seq_ops);
785 }
786 
787 static const struct file_operations br2684_proc_ops = {
788 	.owner   = THIS_MODULE,
789 	.open    = br2684_proc_open,
790 	.read    = seq_read,
791 	.llseek  = seq_lseek,
792 	.release = seq_release,
793 };
794 
795 extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
796 #endif
797 
798 static int __init br2684_init(void)
799 {
800 #ifdef CONFIG_PROC_FS
801 	struct proc_dir_entry *p;
802 	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
803 		return -ENOMEM;
804 	p->proc_fops = &br2684_proc_ops;
805 #endif
806 	register_atm_ioctl(&br2684_ioctl_ops);
807 	return 0;
808 }
809 
810 static void __exit br2684_exit(void)
811 {
812 	struct net_device *net_dev;
813 	struct br2684_dev *brdev;
814 	struct br2684_vcc *brvcc;
815 	deregister_atm_ioctl(&br2684_ioctl_ops);
816 
817 #ifdef CONFIG_PROC_FS
818 	remove_proc_entry("br2684", atm_proc_root);
819 #endif
820 
821 	while (!list_empty(&br2684_devs)) {
822 		net_dev = list_entry_brdev(br2684_devs.next);
823 		brdev = BRPRIV(net_dev);
824 		while (!list_empty(&brdev->brvccs)) {
825 			brvcc = list_entry_brvcc(brdev->brvccs.next);
826 			br2684_close_vcc(brvcc);
827 		}
828 
829 		list_del(&brdev->br2684_devs);
830 		unregister_netdev(net_dev);
831 		free_netdev(net_dev);
832 	}
833 }
834 
835 module_init(br2684_init);
836 module_exit(br2684_exit);
837 
838 MODULE_AUTHOR("Marcell GAL");
839 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
840 MODULE_LICENSE("GPL");
841