xref: /openbmc/linux/net/atm/br2684.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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/config.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/list.h>
12 #include <linux/netdevice.h>
13 #include <linux/skbuff.h>
14 #include <linux/etherdevice.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/ip.h>
17 #include <asm/uaccess.h>
18 #include <net/arp.h>
19 #include <linux/atm.h>
20 #include <linux/atmdev.h>
21 #include <linux/seq_file.h>
22 
23 #include <linux/atmbr2684.h>
24 
25 #include "common.h"
26 #include "ipcommon.h"
27 
28 /*
29  * Define this to use a version of the code which interacts with the higher
30  * layers in a more intellegent way, by always reserving enough space for
31  * our header at the begining of the packet.  However, there may still be
32  * some problems with programs like tcpdump.  In 2.5 we'll sort out what
33  * we need to do to get this perfect.  For now we just will copy the packet
34  * if we need space for the header
35  */
36 /* #define FASTER_VERSION */
37 
38 #ifdef DEBUG
39 #define DPRINTK(format, args...) printk(KERN_DEBUG "br2684: " format, ##args)
40 #else
41 #define DPRINTK(format, args...)
42 #endif
43 
44 #ifdef SKB_DEBUG
45 static void skb_debug(const struct sk_buff *skb)
46 {
47 #define NUM2PRINT 50
48 	char buf[NUM2PRINT * 3 + 1];	/* 3 chars per byte */
49 	int i = 0;
50 	for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
51 		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
52 	}
53 	printk(KERN_DEBUG "br2684: skb: %s\n", buf);
54 }
55 #else
56 #define skb_debug(skb)	do {} while (0)
57 #endif
58 
59 static unsigned char llc_oui_pid_pad[] =
60     { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
61 #define PADLEN	(2)
62 
63 enum br2684_encaps {
64 	e_vc  = BR2684_ENCAPS_VC,
65 	e_llc = BR2684_ENCAPS_LLC,
66 };
67 
68 struct br2684_vcc {
69 	struct atm_vcc  *atmvcc;
70 	struct net_device *device;
71 	/* keep old push,pop functions for chaining */
72 	void (*old_push)(struct atm_vcc *vcc,struct sk_buff *skb);
73 	/* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
74 	enum br2684_encaps encaps;
75 	struct list_head brvccs;
76 #ifdef CONFIG_ATM_BR2684_IPFILTER
77 	struct br2684_filter filter;
78 #endif /* CONFIG_ATM_BR2684_IPFILTER */
79 #ifndef FASTER_VERSION
80 	unsigned copies_needed, copies_failed;
81 #endif /* FASTER_VERSION */
82 };
83 
84 struct br2684_dev {
85 	struct net_device *net_dev;
86 	struct list_head br2684_devs;
87 	int number;
88 	struct list_head brvccs; /* one device <=> one vcc (before xmas) */
89 	struct net_device_stats stats;
90 	int mac_was_set;
91 };
92 
93 /*
94  * This lock should be held for writing any time the list of devices or
95  * their attached vcc's could be altered.  It should be held for reading
96  * any time these are being queried.  Note that we sometimes need to
97  * do read-locking under interrupt context, so write locking must block
98  * the current CPU's interrupts
99  */
100 static DEFINE_RWLOCK(devs_lock);
101 
102 static LIST_HEAD(br2684_devs);
103 
104 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
105 {
106 	return (struct br2684_dev *) net_dev->priv;
107 }
108 
109 static inline struct net_device *list_entry_brdev(const struct list_head *le)
110 {
111 	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
112 }
113 
114 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
115 {
116 	return (struct br2684_vcc *) (atmvcc->user_back);
117 }
118 
119 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
120 {
121 	return list_entry(le, struct br2684_vcc, brvccs);
122 }
123 
124 /* Caller should hold read_lock(&devs_lock) */
125 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
126 {
127 	struct list_head *lh;
128 	struct net_device *net_dev;
129 	switch (s->method) {
130 	case BR2684_FIND_BYNUM:
131 		list_for_each(lh, &br2684_devs) {
132 			net_dev = list_entry_brdev(lh);
133 			if (BRPRIV(net_dev)->number == s->spec.devnum)
134 				return net_dev;
135 		}
136 		break;
137 	case BR2684_FIND_BYIFNAME:
138 		list_for_each(lh, &br2684_devs) {
139 			net_dev = list_entry_brdev(lh);
140 			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
141 				return net_dev;
142 		}
143 		break;
144 	}
145 	return NULL;
146 }
147 
148 /*
149  * Send a packet out a particular vcc.  Not to useful right now, but paves
150  * the way for multiple vcc's per itf.  Returns true if we can send,
151  * otherwise false
152  */
153 static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
154 	struct br2684_vcc *brvcc)
155 {
156 	struct atm_vcc *atmvcc;
157 #ifdef FASTER_VERSION
158 	if (brvcc->encaps == e_llc)
159 		memcpy(skb_push(skb, 8), llc_oui_pid_pad, 8);
160 	/* last 2 bytes of llc_oui_pid_pad are managed by header routines;
161 	   yes, you got it: 8 + 2 = sizeof(llc_oui_pid_pad)
162 	 */
163 #else
164 	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
165 	if (skb_headroom(skb) < minheadroom) {
166 		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
167 		brvcc->copies_needed++;
168 		dev_kfree_skb(skb);
169 		if (skb2 == NULL) {
170 			brvcc->copies_failed++;
171 			return 0;
172 		}
173 		skb = skb2;
174 	}
175 	skb_push(skb, minheadroom);
176 	if (brvcc->encaps == e_llc)
177 		memcpy(skb->data, llc_oui_pid_pad, 10);
178 	else
179 		memset(skb->data, 0, 2);
180 #endif /* FASTER_VERSION */
181 	skb_debug(skb);
182 
183 	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
184 	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
185 	if (!atm_may_send(atmvcc, skb->truesize)) {
186 		/* we free this here for now, because we cannot know in a higher
187 			layer whether the skb point it supplied wasn't freed yet.
188 			now, it always is.
189 		*/
190 		dev_kfree_skb(skb);
191 		return 0;
192 		}
193 	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
194 	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
195 	brdev->stats.tx_packets++;
196 	brdev->stats.tx_bytes += skb->len;
197 	atmvcc->send(atmvcc, skb);
198 	return 1;
199 }
200 
201 static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb,
202 	struct br2684_dev *brdev)
203 {
204 	return list_empty(&brdev->brvccs) ? NULL :
205 	    list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */
206 }
207 
208 static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
209 {
210 	struct br2684_dev *brdev = BRPRIV(dev);
211 	struct br2684_vcc *brvcc;
212 
213 	DPRINTK("br2684_start_xmit, skb->dst=%p\n", skb->dst);
214 	read_lock(&devs_lock);
215 	brvcc = pick_outgoing_vcc(skb, brdev);
216 	if (brvcc == NULL) {
217 		DPRINTK("no vcc attached to dev %s\n", dev->name);
218 		brdev->stats.tx_errors++;
219 		brdev->stats.tx_carrier_errors++;
220 		/* netif_stop_queue(dev); */
221 		dev_kfree_skb(skb);
222 		read_unlock(&devs_lock);
223 		return 0;
224 	}
225 	if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
226 		/*
227 		 * We should probably use netif_*_queue() here, but that
228 		 * involves added complication.  We need to walk before
229 		 * we can run
230 		 */
231 		/* don't free here! this pointer might be no longer valid!
232 		dev_kfree_skb(skb);
233 		*/
234 		brdev->stats.tx_errors++;
235 		brdev->stats.tx_fifo_errors++;
236 	}
237 	read_unlock(&devs_lock);
238 	return 0;
239 }
240 
241 static struct net_device_stats *br2684_get_stats(struct net_device *dev)
242 {
243 	DPRINTK("br2684_get_stats\n");
244 	return &BRPRIV(dev)->stats;
245 }
246 
247 #ifdef FASTER_VERSION
248 /*
249  * These mirror eth_header and eth_header_cache.  They are not usually
250  * exported for use in modules, so we grab them from net_device
251  * after ether_setup() is done with it.  Bit of a hack.
252  */
253 static int (*my_eth_header)(struct sk_buff *, struct net_device *,
254 	unsigned short, void *, void *, unsigned);
255 static int (*my_eth_header_cache)(struct neighbour *, struct hh_cache *);
256 
257 static int
258 br2684_header(struct sk_buff *skb, struct net_device *dev,
259 	      unsigned short type, void *daddr, void *saddr, unsigned len)
260 {
261 	u16 *pad_before_eth;
262 	int t = my_eth_header(skb, dev, type, daddr, saddr, len);
263 	if (t > 0) {
264 		pad_before_eth = (u16 *) skb_push(skb, 2);
265 		*pad_before_eth = 0;
266 		return dev->hard_header_len;	/* or return 16; ? */
267 	} else
268 		return t;
269 }
270 
271 static int
272 br2684_header_cache(struct neighbour *neigh, struct hh_cache *hh)
273 {
274 /* hh_data is 16 bytes long. if encaps is ether-llc we need 24, so
275 xmit will add the additional header part in that case */
276 	u16 *pad_before_eth = (u16 *)(hh->hh_data);
277 	int t = my_eth_header_cache(neigh, hh);
278 	DPRINTK("br2684_header_cache, neigh=%p, hh_cache=%p\n", neigh, hh);
279 	if (t < 0)
280 		return t;
281 	else {
282 		*pad_before_eth = 0;
283 		hh->hh_len = PADLEN + ETH_HLEN;
284 	}
285 	return 0;
286 }
287 
288 /*
289  * This is similar to eth_type_trans, which cannot be used because of
290  * our dev->hard_header_len
291  */
292 static inline __be16 br_type_trans(struct sk_buff *skb, struct net_device *dev)
293 {
294 	struct ethhdr *eth;
295 	unsigned char *rawp;
296 	eth = eth_hdr(skb);
297 
298 	if (*eth->h_dest & 1) {
299 		if (memcmp(eth->h_dest, dev->broadcast, ETH_ALEN) == 0)
300 			skb->pkt_type = PACKET_BROADCAST;
301 		else
302 			skb->pkt_type = PACKET_MULTICAST;
303 	}
304 
305 	else if (memcmp(eth->h_dest, dev->dev_addr, ETH_ALEN))
306 		skb->pkt_type = PACKET_OTHERHOST;
307 
308 	if (ntohs(eth->h_proto) >= 1536)
309 		return eth->h_proto;
310 
311 	rawp = skb->data;
312 
313 	/*
314 	 * This is a magic hack to spot IPX packets. Older Novell breaks
315 	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
316 	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
317 	 * won't work for fault tolerant netware but does for the rest.
318 	 */
319 	if (*(unsigned short *) rawp == 0xFFFF)
320 		return htons(ETH_P_802_3);
321 
322 	/*
323 	 * Real 802.2 LLC
324 	 */
325 	return htons(ETH_P_802_2);
326 }
327 #endif /* FASTER_VERSION */
328 
329 /*
330  * We remember when the MAC gets set, so we don't override it later with
331  * the ESI of the ATM card of the first VC
332  */
333 static int (*my_eth_mac_addr)(struct net_device *, void *);
334 static int br2684_mac_addr(struct net_device *dev, void *p)
335 {
336 	int err = my_eth_mac_addr(dev, p);
337 	if (!err)
338 		BRPRIV(dev)->mac_was_set = 1;
339 	return err;
340 }
341 
342 #ifdef CONFIG_ATM_BR2684_IPFILTER
343 /* this IOCTL is experimental. */
344 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user *arg)
345 {
346 	struct br2684_vcc *brvcc;
347 	struct br2684_filter_set fs;
348 
349 	if (copy_from_user(&fs, arg, sizeof fs))
350 		return -EFAULT;
351 	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
352 		/*
353 		 * This is really a per-vcc thing, but we can also search
354 		 * by device
355 		 */
356 		struct br2684_dev *brdev;
357 		read_lock(&devs_lock);
358 		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
359 		if (brdev == NULL || list_empty(&brdev->brvccs) ||
360 		    brdev->brvccs.next != brdev->brvccs.prev)  /* >1 VCC */
361 			brvcc = NULL;
362 		else
363 			brvcc = list_entry_brvcc(brdev->brvccs.next);
364 		read_unlock(&devs_lock);
365 		if (brvcc == NULL)
366 			return -ESRCH;
367 	} else
368 		brvcc = BR2684_VCC(atmvcc);
369 	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
370 	return 0;
371 }
372 
373 /* Returns 1 if packet should be dropped */
374 static inline int
375 packet_fails_filter(u16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
376 {
377 	if (brvcc->filter.netmask == 0)
378 		return 0;			/* no filter in place */
379 	if (type == __constant_htons(ETH_P_IP) &&
380 	    (((struct iphdr *) (skb->data))->daddr & brvcc->filter.
381 	     netmask) == brvcc->filter.prefix)
382 		return 0;
383 	if (type == __constant_htons(ETH_P_ARP))
384 		return 0;
385 	/* TODO: we should probably filter ARPs too.. don't want to have
386 	 *   them returning values that don't make sense, or is that ok?
387 	 */
388 	return 1;		/* drop */
389 }
390 #endif /* CONFIG_ATM_BR2684_IPFILTER */
391 
392 static void br2684_close_vcc(struct br2684_vcc *brvcc)
393 {
394 	DPRINTK("removing VCC %p from dev %p\n", brvcc, brvcc->device);
395 	write_lock_irq(&devs_lock);
396 	list_del(&brvcc->brvccs);
397 	write_unlock_irq(&devs_lock);
398 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
399 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
400 	kfree(brvcc);
401 	module_put(THIS_MODULE);
402 }
403 
404 /* when AAL5 PDU comes in: */
405 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
406 {
407 	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
408 	struct net_device *net_dev = brvcc->device;
409 	struct br2684_dev *brdev = BRPRIV(net_dev);
410 	int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
411 
412 	DPRINTK("br2684_push\n");
413 
414 	if (unlikely(skb == NULL)) {
415 		/* skb==NULL means VCC is being destroyed */
416 		br2684_close_vcc(brvcc);
417 		if (list_empty(&brdev->brvccs)) {
418 			read_lock(&devs_lock);
419 			list_del(&brdev->br2684_devs);
420 			read_unlock(&devs_lock);
421 			unregister_netdev(net_dev);
422 			free_netdev(net_dev);
423 		}
424 		return;
425 	}
426 
427 	skb_debug(skb);
428 	atm_return(atmvcc, skb->truesize);
429 	DPRINTK("skb from brdev %p\n", brdev);
430 	if (brvcc->encaps == e_llc) {
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 		if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
435 			brdev->stats.rx_errors++;
436 			dev_kfree_skb(skb);
437 			return;
438 		}
439 
440 		/* Strip FCS if present */
441 		if (skb->len > 7 && skb->data[7] == 0x01)
442 			__skb_trim(skb, skb->len - 4);
443 	} else {
444 		plen = PADLEN + ETH_HLEN;	/* pad, dstmac,srcmac, ethtype */
445 		/* first 2 chars should be 0 */
446 		if (*((u16 *) (skb->data)) != 0) {
447 			brdev->stats.rx_errors++;
448 			dev_kfree_skb(skb);
449 			return;
450 		}
451 	}
452 	if (skb->len < plen) {
453 		brdev->stats.rx_errors++;
454 		dev_kfree_skb(skb);	/* dev_ not needed? */
455 		return;
456 	}
457 
458 #ifdef FASTER_VERSION
459 	/* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier,
460 	   than should be. What else should I set? */
461 	skb_pull(skb, plen);
462 	skb->mac.raw = ((char *) (skb->data)) - ETH_HLEN;
463 	skb->pkt_type = PACKET_HOST;
464 #ifdef CONFIG_BR2684_FAST_TRANS
465 	skb->protocol = ((u16 *) skb->data)[-1];
466 #else				/* some protocols might require this: */
467 	skb->protocol = br_type_trans(skb, net_dev);
468 #endif /* CONFIG_BR2684_FAST_TRANS */
469 #else
470 	skb_pull(skb, plen - ETH_HLEN);
471 	skb->protocol = eth_type_trans(skb, net_dev);
472 #endif /* FASTER_VERSION */
473 #ifdef CONFIG_ATM_BR2684_IPFILTER
474 	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
475 		brdev->stats.rx_dropped++;
476 		dev_kfree_skb(skb);
477 		return;
478 	}
479 #endif /* CONFIG_ATM_BR2684_IPFILTER */
480 	skb->dev = net_dev;
481 	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
482 	DPRINTK("received packet's protocol: %x\n", ntohs(skb->protocol));
483 	skb_debug(skb);
484 	if (unlikely(!(net_dev->flags & IFF_UP))) {
485 		/* sigh, interface is down */
486 		brdev->stats.rx_dropped++;
487 		dev_kfree_skb(skb);
488 		return;
489 	}
490 	brdev->stats.rx_packets++;
491 	brdev->stats.rx_bytes += skb->len;
492 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
493 	netif_rx(skb);
494 }
495 
496 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user *arg)
497 {
498 /* assign a vcc to a dev
499 Note: we do not have explicit unassign, but look at _push()
500 */
501 	int err;
502 	struct br2684_vcc *brvcc;
503 	struct sk_buff_head copy;
504 	struct sk_buff *skb;
505 	struct br2684_dev *brdev;
506 	struct net_device *net_dev;
507 	struct atm_backend_br2684 be;
508 
509 	if (copy_from_user(&be, arg, sizeof be))
510 		return -EFAULT;
511 	brvcc = kmalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
512 	if (!brvcc)
513 		return -ENOMEM;
514 	memset(brvcc, 0, sizeof(struct br2684_vcc));
515 	write_lock_irq(&devs_lock);
516 	net_dev = br2684_find_dev(&be.ifspec);
517 	if (net_dev == NULL) {
518 		printk(KERN_ERR
519 		    "br2684: tried to attach to non-existant device\n");
520 		err = -ENXIO;
521 		goto error;
522 	}
523 	brdev = BRPRIV(net_dev);
524 	if (atmvcc->push == NULL) {
525 		err = -EBADFD;
526 		goto error;
527 	}
528 	if (!list_empty(&brdev->brvccs)) {
529 		/* Only 1 VCC/dev right now */
530 		err = -EEXIST;
531 		goto error;
532 	}
533 	if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
534 	    be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
535 	    BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
536 	    be.min_size != 0) {
537 		err = -EINVAL;
538 		goto error;
539 	}
540 	DPRINTK("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
541 		brvcc);
542 	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
543 		unsigned char *esi = atmvcc->dev->esi;
544 		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
545 			memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
546 		else
547 			net_dev->dev_addr[2] = 1;
548 	}
549 	list_add(&brvcc->brvccs, &brdev->brvccs);
550 	write_unlock_irq(&devs_lock);
551 	brvcc->device = net_dev;
552 	brvcc->atmvcc = atmvcc;
553 	atmvcc->user_back = brvcc;
554 	brvcc->encaps = (enum br2684_encaps) be.encaps;
555 	brvcc->old_push = atmvcc->push;
556 	barrier();
557 	atmvcc->push = br2684_push;
558 	skb_queue_head_init(&copy);
559 	skb_migrate(&sk_atm(atmvcc)->sk_receive_queue, &copy);
560 	while ((skb = skb_dequeue(&copy)) != NULL) {
561 		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
562 		BRPRIV(skb->dev)->stats.rx_packets--;
563 		br2684_push(atmvcc, skb);
564 	}
565 	__module_get(THIS_MODULE);
566 	return 0;
567     error:
568 	write_unlock_irq(&devs_lock);
569 	kfree(brvcc);
570 	return err;
571 }
572 
573 static void br2684_setup(struct net_device *netdev)
574 {
575 	struct br2684_dev *brdev = BRPRIV(netdev);
576 
577 	ether_setup(netdev);
578 	brdev->net_dev = netdev;
579 
580 #ifdef FASTER_VERSION
581 	my_eth_header = netdev->hard_header;
582 	netdev->hard_header = br2684_header;
583 	my_eth_header_cache = netdev->hard_header_cache;
584 	netdev->hard_header_cache = br2684_header_cache;
585 	netdev->hard_header_len = sizeof(llc_oui_pid_pad) + ETH_HLEN;	/* 10 + 14 */
586 #endif
587 	my_eth_mac_addr = netdev->set_mac_address;
588 	netdev->set_mac_address = br2684_mac_addr;
589 	netdev->hard_start_xmit = br2684_start_xmit;
590 	netdev->get_stats = br2684_get_stats;
591 
592 	INIT_LIST_HEAD(&brdev->brvccs);
593 }
594 
595 static int br2684_create(void __user *arg)
596 {
597 	int err;
598 	struct net_device *netdev;
599 	struct br2684_dev *brdev;
600 	struct atm_newif_br2684 ni;
601 
602 	DPRINTK("br2684_create\n");
603 
604 	if (copy_from_user(&ni, arg, sizeof ni)) {
605 		return -EFAULT;
606 	}
607 	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
608 		return -EINVAL;
609 	}
610 
611 	netdev = alloc_netdev(sizeof(struct br2684_dev),
612 			      ni.ifname[0] ? ni.ifname : "nas%d",
613 			      br2684_setup);
614 	if (!netdev)
615 		return -ENOMEM;
616 
617 	brdev = BRPRIV(netdev);
618 
619 	DPRINTK("registered netdev %s\n", netdev->name);
620 	/* open, stop, do_ioctl ? */
621 	err = register_netdev(netdev);
622 	if (err < 0) {
623 		printk(KERN_ERR "br2684_create: register_netdev failed\n");
624 		free_netdev(netdev);
625 		return err;
626 	}
627 
628 	write_lock_irq(&devs_lock);
629 	brdev->number = list_empty(&br2684_devs) ? 1 :
630 	    BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
631 	list_add_tail(&brdev->br2684_devs, &br2684_devs);
632 	write_unlock_irq(&devs_lock);
633 	return 0;
634 }
635 
636 /*
637  * This handles ioctls actually performed on our vcc - we must return
638  * -ENOIOCTLCMD for any unrecognized ioctl
639  */
640 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
641 	unsigned long arg)
642 {
643 	struct atm_vcc *atmvcc = ATM_SD(sock);
644 	void __user *argp = (void __user *)arg;
645 
646 	int err;
647 	switch(cmd) {
648 	case ATM_SETBACKEND:
649 	case ATM_NEWBACKENDIF: {
650 		atm_backend_t b;
651 		err = get_user(b, (atm_backend_t __user *) argp);
652 		if (err)
653 			return -EFAULT;
654 		if (b != ATM_BACKEND_BR2684)
655 			return -ENOIOCTLCMD;
656 		if (!capable(CAP_NET_ADMIN))
657 			return -EPERM;
658 		if (cmd == ATM_SETBACKEND)
659 			return br2684_regvcc(atmvcc, argp);
660 		else
661 			return br2684_create(argp);
662 		}
663 #ifdef CONFIG_ATM_BR2684_IPFILTER
664 	case BR2684_SETFILT:
665 		if (atmvcc->push != br2684_push)
666 			return -ENOIOCTLCMD;
667 		if (!capable(CAP_NET_ADMIN))
668 			return -EPERM;
669 		err = br2684_setfilt(atmvcc, argp);
670 		return err;
671 #endif /* CONFIG_ATM_BR2684_IPFILTER */
672 	}
673 	return -ENOIOCTLCMD;
674 }
675 
676 static struct atm_ioctl br2684_ioctl_ops = {
677 	.owner	= THIS_MODULE,
678 	.ioctl	= br2684_ioctl,
679 };
680 
681 
682 #ifdef CONFIG_PROC_FS
683 static void *br2684_seq_start(struct seq_file *seq, loff_t *pos)
684 {
685 	loff_t offs = 0;
686 	struct br2684_dev *brd;
687 
688 	read_lock(&devs_lock);
689 
690 	list_for_each_entry(brd, &br2684_devs, br2684_devs) {
691 		if (offs == *pos)
692 			return brd;
693 		++offs;
694 	}
695 	return NULL;
696 }
697 
698 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t *pos)
699 {
700 	struct br2684_dev *brd = v;
701 
702 	++*pos;
703 
704 	brd = list_entry(brd->br2684_devs.next,
705 			 struct br2684_dev, br2684_devs);
706 	return (&brd->br2684_devs != &br2684_devs) ? brd : NULL;
707 }
708 
709 static void br2684_seq_stop(struct seq_file *seq, void *v)
710 {
711 	read_unlock(&devs_lock);
712 }
713 
714 static int br2684_seq_show(struct seq_file *seq, void *v)
715 {
716 	const struct br2684_dev *brdev = v;
717 	const struct net_device *net_dev = brdev->net_dev;
718 	const struct br2684_vcc *brvcc;
719 
720 	seq_printf(seq, "dev %.16s: num=%d, mac=%02X:%02X:"
721 		       "%02X:%02X:%02X:%02X (%s)\n", net_dev->name,
722 		       brdev->number,
723 		       net_dev->dev_addr[0],
724 		       net_dev->dev_addr[1],
725 		       net_dev->dev_addr[2],
726 		       net_dev->dev_addr[3],
727 		       net_dev->dev_addr[4],
728 		       net_dev->dev_addr[5],
729 		       brdev->mac_was_set ? "set" : "auto");
730 
731 	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
732 		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
733 #ifndef FASTER_VERSION
734 				    ", failed copies %u/%u"
735 #endif /* FASTER_VERSION */
736 				    "\n", brvcc->atmvcc->dev->number,
737 				    brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
738 				    (brvcc->encaps == e_llc) ? "LLC" : "VC"
739 #ifndef FASTER_VERSION
740 				    , brvcc->copies_failed
741 				    , brvcc->copies_needed
742 #endif /* FASTER_VERSION */
743 				    );
744 #ifdef CONFIG_ATM_BR2684_IPFILTER
745 #define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
746 #define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
747 			if (brvcc->filter.netmask != 0)
748 				seq_printf(seq, "    filter=%d.%d.%d.%d/"
749 						"%d.%d.%d.%d\n",
750 						bs(prefix), bs(netmask));
751 #undef bs
752 #undef b1
753 #endif /* CONFIG_ATM_BR2684_IPFILTER */
754 	}
755 	return 0;
756 }
757 
758 static struct seq_operations br2684_seq_ops = {
759 	.start = br2684_seq_start,
760 	.next  = br2684_seq_next,
761 	.stop  = br2684_seq_stop,
762 	.show  = br2684_seq_show,
763 };
764 
765 static int br2684_proc_open(struct inode *inode, struct file *file)
766 {
767 	return seq_open(file, &br2684_seq_ops);
768 }
769 
770 static struct file_operations br2684_proc_ops = {
771 	.owner   = THIS_MODULE,
772 	.open    = br2684_proc_open,
773 	.read    = seq_read,
774 	.llseek  = seq_lseek,
775 	.release = seq_release,
776 };
777 
778 extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
779 #endif
780 
781 static int __init br2684_init(void)
782 {
783 #ifdef CONFIG_PROC_FS
784 	struct proc_dir_entry *p;
785 	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
786 		return -ENOMEM;
787 	p->proc_fops = &br2684_proc_ops;
788 #endif
789 	register_atm_ioctl(&br2684_ioctl_ops);
790 	return 0;
791 }
792 
793 static void __exit br2684_exit(void)
794 {
795 	struct net_device *net_dev;
796 	struct br2684_dev *brdev;
797 	struct br2684_vcc *brvcc;
798 	deregister_atm_ioctl(&br2684_ioctl_ops);
799 
800 #ifdef CONFIG_PROC_FS
801 	remove_proc_entry("br2684", atm_proc_root);
802 #endif
803 
804 	while (!list_empty(&br2684_devs)) {
805 		net_dev = list_entry_brdev(br2684_devs.next);
806 		brdev = BRPRIV(net_dev);
807 		while (!list_empty(&brdev->brvccs)) {
808 			brvcc = list_entry_brvcc(brdev->brvccs.next);
809 			br2684_close_vcc(brvcc);
810 		}
811 
812 		list_del(&brdev->br2684_devs);
813 		unregister_netdev(net_dev);
814 		free_netdev(net_dev);
815 	}
816 }
817 
818 module_init(br2684_init);
819 module_exit(br2684_exit);
820 
821 MODULE_AUTHOR("Marcell GAL");
822 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
823 MODULE_LICENSE("GPL");
824