xref: /linux/net/atm/br2684.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/capability.h>
22 #include <linux/seq_file.h>
23 
24 #include <linux/atmbr2684.h>
25 
26 #include "common.h"
27 #include "ipcommon.h"
28 
29 /*
30  * Define this to use a version of the code which interacts with the higher
31  * layers in a more intellegent way, by always reserving enough space for
32  * our header at the begining of the packet.  However, there may still be
33  * some problems with programs like tcpdump.  In 2.5 we'll sort out what
34  * we need to do to get this perfect.  For now we just will copy the packet
35  * if we need space for the header
36  */
37 /* #define FASTER_VERSION */
38 
39 #ifdef DEBUG
40 #define DPRINTK(format, args...) printk(KERN_DEBUG "br2684: " format, ##args)
41 #else
42 #define DPRINTK(format, args...)
43 #endif
44 
45 #ifdef SKB_DEBUG
46 static void skb_debug(const struct sk_buff *skb)
47 {
48 #define NUM2PRINT 50
49 	char buf[NUM2PRINT * 3 + 1];	/* 3 chars per byte */
50 	int i = 0;
51 	for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
52 		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
53 	}
54 	printk(KERN_DEBUG "br2684: skb: %s\n", buf);
55 }
56 #else
57 #define skb_debug(skb)	do {} while (0)
58 #endif
59 
60 static unsigned char llc_oui_pid_pad[] =
61     { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
62 #define PADLEN	(2)
63 
64 enum br2684_encaps {
65 	e_vc  = BR2684_ENCAPS_VC,
66 	e_llc = BR2684_ENCAPS_LLC,
67 };
68 
69 struct br2684_vcc {
70 	struct atm_vcc  *atmvcc;
71 	struct net_device *device;
72 	/* keep old push,pop functions for chaining */
73 	void (*old_push)(struct atm_vcc *vcc,struct sk_buff *skb);
74 	/* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
75 	enum br2684_encaps encaps;
76 	struct list_head brvccs;
77 #ifdef CONFIG_ATM_BR2684_IPFILTER
78 	struct br2684_filter filter;
79 #endif /* CONFIG_ATM_BR2684_IPFILTER */
80 #ifndef FASTER_VERSION
81 	unsigned copies_needed, copies_failed;
82 #endif /* FASTER_VERSION */
83 };
84 
85 struct br2684_dev {
86 	struct net_device *net_dev;
87 	struct list_head br2684_devs;
88 	int number;
89 	struct list_head brvccs; /* one device <=> one vcc (before xmas) */
90 	struct net_device_stats stats;
91 	int mac_was_set;
92 };
93 
94 /*
95  * This lock should be held for writing any time the list of devices or
96  * their attached vcc's could be altered.  It should be held for reading
97  * any time these are being queried.  Note that we sometimes need to
98  * do read-locking under interrupt context, so write locking must block
99  * the current CPU's interrupts
100  */
101 static DEFINE_RWLOCK(devs_lock);
102 
103 static LIST_HEAD(br2684_devs);
104 
105 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
106 {
107 	return (struct br2684_dev *) net_dev->priv;
108 }
109 
110 static inline struct net_device *list_entry_brdev(const struct list_head *le)
111 {
112 	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
113 }
114 
115 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
116 {
117 	return (struct br2684_vcc *) (atmvcc->user_back);
118 }
119 
120 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
121 {
122 	return list_entry(le, struct br2684_vcc, brvccs);
123 }
124 
125 /* Caller should hold read_lock(&devs_lock) */
126 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
127 {
128 	struct list_head *lh;
129 	struct net_device *net_dev;
130 	switch (s->method) {
131 	case BR2684_FIND_BYNUM:
132 		list_for_each(lh, &br2684_devs) {
133 			net_dev = list_entry_brdev(lh);
134 			if (BRPRIV(net_dev)->number == s->spec.devnum)
135 				return net_dev;
136 		}
137 		break;
138 	case BR2684_FIND_BYIFNAME:
139 		list_for_each(lh, &br2684_devs) {
140 			net_dev = list_entry_brdev(lh);
141 			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
142 				return net_dev;
143 		}
144 		break;
145 	}
146 	return NULL;
147 }
148 
149 /*
150  * Send a packet out a particular vcc.  Not to useful right now, but paves
151  * the way for multiple vcc's per itf.  Returns true if we can send,
152  * otherwise false
153  */
154 static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
155 	struct br2684_vcc *brvcc)
156 {
157 	struct atm_vcc *atmvcc;
158 #ifdef FASTER_VERSION
159 	if (brvcc->encaps == e_llc)
160 		memcpy(skb_push(skb, 8), llc_oui_pid_pad, 8);
161 	/* last 2 bytes of llc_oui_pid_pad are managed by header routines;
162 	   yes, you got it: 8 + 2 = sizeof(llc_oui_pid_pad)
163 	 */
164 #else
165 	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
166 	if (skb_headroom(skb) < minheadroom) {
167 		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
168 		brvcc->copies_needed++;
169 		dev_kfree_skb(skb);
170 		if (skb2 == NULL) {
171 			brvcc->copies_failed++;
172 			return 0;
173 		}
174 		skb = skb2;
175 	}
176 	skb_push(skb, minheadroom);
177 	if (brvcc->encaps == e_llc)
178 		memcpy(skb->data, llc_oui_pid_pad, 10);
179 	else
180 		memset(skb->data, 0, 2);
181 #endif /* FASTER_VERSION */
182 	skb_debug(skb);
183 
184 	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
185 	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
186 	if (!atm_may_send(atmvcc, skb->truesize)) {
187 		/* we free this here for now, because we cannot know in a higher
188 			layer whether the skb point it supplied wasn't freed yet.
189 			now, it always is.
190 		*/
191 		dev_kfree_skb(skb);
192 		return 0;
193 		}
194 	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
195 	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
196 	brdev->stats.tx_packets++;
197 	brdev->stats.tx_bytes += skb->len;
198 	atmvcc->send(atmvcc, skb);
199 	return 1;
200 }
201 
202 static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb,
203 	struct br2684_dev *brdev)
204 {
205 	return list_empty(&brdev->brvccs) ? NULL :
206 	    list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */
207 }
208 
209 static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
210 {
211 	struct br2684_dev *brdev = BRPRIV(dev);
212 	struct br2684_vcc *brvcc;
213 
214 	DPRINTK("br2684_start_xmit, skb->dst=%p\n", skb->dst);
215 	read_lock(&devs_lock);
216 	brvcc = pick_outgoing_vcc(skb, brdev);
217 	if (brvcc == NULL) {
218 		DPRINTK("no vcc attached to dev %s\n", dev->name);
219 		brdev->stats.tx_errors++;
220 		brdev->stats.tx_carrier_errors++;
221 		/* netif_stop_queue(dev); */
222 		dev_kfree_skb(skb);
223 		read_unlock(&devs_lock);
224 		return 0;
225 	}
226 	if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
227 		/*
228 		 * We should probably use netif_*_queue() here, but that
229 		 * involves added complication.  We need to walk before
230 		 * we can run
231 		 */
232 		/* don't free here! this pointer might be no longer valid!
233 		dev_kfree_skb(skb);
234 		*/
235 		brdev->stats.tx_errors++;
236 		brdev->stats.tx_fifo_errors++;
237 	}
238 	read_unlock(&devs_lock);
239 	return 0;
240 }
241 
242 static struct net_device_stats *br2684_get_stats(struct net_device *dev)
243 {
244 	DPRINTK("br2684_get_stats\n");
245 	return &BRPRIV(dev)->stats;
246 }
247 
248 #ifdef FASTER_VERSION
249 /*
250  * These mirror eth_header and eth_header_cache.  They are not usually
251  * exported for use in modules, so we grab them from net_device
252  * after ether_setup() is done with it.  Bit of a hack.
253  */
254 static int (*my_eth_header)(struct sk_buff *, struct net_device *,
255 	unsigned short, void *, void *, unsigned);
256 static int (*my_eth_header_cache)(struct neighbour *, struct hh_cache *);
257 
258 static int
259 br2684_header(struct sk_buff *skb, struct net_device *dev,
260 	      unsigned short type, void *daddr, void *saddr, unsigned len)
261 {
262 	u16 *pad_before_eth;
263 	int t = my_eth_header(skb, dev, type, daddr, saddr, len);
264 	if (t > 0) {
265 		pad_before_eth = (u16 *) skb_push(skb, 2);
266 		*pad_before_eth = 0;
267 		return dev->hard_header_len;	/* or return 16; ? */
268 	} else
269 		return t;
270 }
271 
272 static int
273 br2684_header_cache(struct neighbour *neigh, struct hh_cache *hh)
274 {
275 /* hh_data is 16 bytes long. if encaps is ether-llc we need 24, so
276 xmit will add the additional header part in that case */
277 	u16 *pad_before_eth = (u16 *)(hh->hh_data);
278 	int t = my_eth_header_cache(neigh, hh);
279 	DPRINTK("br2684_header_cache, neigh=%p, hh_cache=%p\n", neigh, hh);
280 	if (t < 0)
281 		return t;
282 	else {
283 		*pad_before_eth = 0;
284 		hh->hh_len = PADLEN + ETH_HLEN;
285 	}
286 	return 0;
287 }
288 
289 /*
290  * This is similar to eth_type_trans, which cannot be used because of
291  * our dev->hard_header_len
292  */
293 static inline __be16 br_type_trans(struct sk_buff *skb, struct net_device *dev)
294 {
295 	struct ethhdr *eth;
296 	unsigned char *rawp;
297 	eth = eth_hdr(skb);
298 
299 	if (is_multicast_ether_addr(eth->h_dest)) {
300 		if (!compare_ether_addr(eth->h_dest, dev->broadcast))
301 			skb->pkt_type = PACKET_BROADCAST;
302 		else
303 			skb->pkt_type = PACKET_MULTICAST;
304 	}
305 
306 	else if (compare_ether_addr(eth->h_dest, dev->dev_addr))
307 		skb->pkt_type = PACKET_OTHERHOST;
308 
309 	if (ntohs(eth->h_proto) >= 1536)
310 		return eth->h_proto;
311 
312 	rawp = skb->data;
313 
314 	/*
315 	 * This is a magic hack to spot IPX packets. Older Novell breaks
316 	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
317 	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
318 	 * won't work for fault tolerant netware but does for the rest.
319 	 */
320 	if (*(unsigned short *) rawp == 0xFFFF)
321 		return htons(ETH_P_802_3);
322 
323 	/*
324 	 * Real 802.2 LLC
325 	 */
326 	return htons(ETH_P_802_2);
327 }
328 #endif /* FASTER_VERSION */
329 
330 /*
331  * We remember when the MAC gets set, so we don't override it later with
332  * the ESI of the ATM card of the first VC
333  */
334 static int (*my_eth_mac_addr)(struct net_device *, void *);
335 static int br2684_mac_addr(struct net_device *dev, void *p)
336 {
337 	int err = my_eth_mac_addr(dev, p);
338 	if (!err)
339 		BRPRIV(dev)->mac_was_set = 1;
340 	return err;
341 }
342 
343 #ifdef CONFIG_ATM_BR2684_IPFILTER
344 /* this IOCTL is experimental. */
345 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user *arg)
346 {
347 	struct br2684_vcc *brvcc;
348 	struct br2684_filter_set fs;
349 
350 	if (copy_from_user(&fs, arg, sizeof fs))
351 		return -EFAULT;
352 	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
353 		/*
354 		 * This is really a per-vcc thing, but we can also search
355 		 * by device
356 		 */
357 		struct br2684_dev *brdev;
358 		read_lock(&devs_lock);
359 		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
360 		if (brdev == NULL || list_empty(&brdev->brvccs) ||
361 		    brdev->brvccs.next != brdev->brvccs.prev)  /* >1 VCC */
362 			brvcc = NULL;
363 		else
364 			brvcc = list_entry_brvcc(brdev->brvccs.next);
365 		read_unlock(&devs_lock);
366 		if (brvcc == NULL)
367 			return -ESRCH;
368 	} else
369 		brvcc = BR2684_VCC(atmvcc);
370 	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
371 	return 0;
372 }
373 
374 /* Returns 1 if packet should be dropped */
375 static inline int
376 packet_fails_filter(u16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
377 {
378 	if (brvcc->filter.netmask == 0)
379 		return 0;			/* no filter in place */
380 	if (type == __constant_htons(ETH_P_IP) &&
381 	    (((struct iphdr *) (skb->data))->daddr & brvcc->filter.
382 	     netmask) == brvcc->filter.prefix)
383 		return 0;
384 	if (type == __constant_htons(ETH_P_ARP))
385 		return 0;
386 	/* TODO: we should probably filter ARPs too.. don't want to have
387 	 *   them returning values that don't make sense, or is that ok?
388 	 */
389 	return 1;		/* drop */
390 }
391 #endif /* CONFIG_ATM_BR2684_IPFILTER */
392 
393 static void br2684_close_vcc(struct br2684_vcc *brvcc)
394 {
395 	DPRINTK("removing VCC %p from dev %p\n", brvcc, brvcc->device);
396 	write_lock_irq(&devs_lock);
397 	list_del(&brvcc->brvccs);
398 	write_unlock_irq(&devs_lock);
399 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
400 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
401 	kfree(brvcc);
402 	module_put(THIS_MODULE);
403 }
404 
405 /* when AAL5 PDU comes in: */
406 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
407 {
408 	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
409 	struct net_device *net_dev = brvcc->device;
410 	struct br2684_dev *brdev = BRPRIV(net_dev);
411 	int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
412 
413 	DPRINTK("br2684_push\n");
414 
415 	if (unlikely(skb == NULL)) {
416 		/* skb==NULL means VCC is being destroyed */
417 		br2684_close_vcc(brvcc);
418 		if (list_empty(&brdev->brvccs)) {
419 			read_lock(&devs_lock);
420 			list_del(&brdev->br2684_devs);
421 			read_unlock(&devs_lock);
422 			unregister_netdev(net_dev);
423 			free_netdev(net_dev);
424 		}
425 		return;
426 	}
427 
428 	skb_debug(skb);
429 	atm_return(atmvcc, skb->truesize);
430 	DPRINTK("skb from brdev %p\n", brdev);
431 	if (brvcc->encaps == e_llc) {
432 		/* let us waste some time for checking the encapsulation.
433 		   Note, that only 7 char is checked so frames with a valid FCS
434 		   are also accepted (but FCS is not checked of course) */
435 		if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
436 			brdev->stats.rx_errors++;
437 			dev_kfree_skb(skb);
438 			return;
439 		}
440 
441 		/* Strip FCS if present */
442 		if (skb->len > 7 && skb->data[7] == 0x01)
443 			__skb_trim(skb, skb->len - 4);
444 	} else {
445 		plen = PADLEN + ETH_HLEN;	/* pad, dstmac,srcmac, ethtype */
446 		/* first 2 chars should be 0 */
447 		if (*((u16 *) (skb->data)) != 0) {
448 			brdev->stats.rx_errors++;
449 			dev_kfree_skb(skb);
450 			return;
451 		}
452 	}
453 	if (skb->len < plen) {
454 		brdev->stats.rx_errors++;
455 		dev_kfree_skb(skb);	/* dev_ not needed? */
456 		return;
457 	}
458 
459 #ifdef FASTER_VERSION
460 	/* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier,
461 	   than should be. What else should I set? */
462 	skb_pull(skb, plen);
463 	skb->mac.raw = ((char *) (skb->data)) - ETH_HLEN;
464 	skb->pkt_type = PACKET_HOST;
465 #ifdef CONFIG_BR2684_FAST_TRANS
466 	skb->protocol = ((u16 *) skb->data)[-1];
467 #else				/* some protocols might require this: */
468 	skb->protocol = br_type_trans(skb, net_dev);
469 #endif /* CONFIG_BR2684_FAST_TRANS */
470 #else
471 	skb_pull(skb, plen - ETH_HLEN);
472 	skb->protocol = eth_type_trans(skb, net_dev);
473 #endif /* FASTER_VERSION */
474 #ifdef CONFIG_ATM_BR2684_IPFILTER
475 	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
476 		brdev->stats.rx_dropped++;
477 		dev_kfree_skb(skb);
478 		return;
479 	}
480 #endif /* CONFIG_ATM_BR2684_IPFILTER */
481 	skb->dev = net_dev;
482 	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
483 	DPRINTK("received packet's protocol: %x\n", ntohs(skb->protocol));
484 	skb_debug(skb);
485 	if (unlikely(!(net_dev->flags & IFF_UP))) {
486 		/* sigh, interface is down */
487 		brdev->stats.rx_dropped++;
488 		dev_kfree_skb(skb);
489 		return;
490 	}
491 	brdev->stats.rx_packets++;
492 	brdev->stats.rx_bytes += skb->len;
493 	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
494 	netif_rx(skb);
495 }
496 
497 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user *arg)
498 {
499 /* assign a vcc to a dev
500 Note: we do not have explicit unassign, but look at _push()
501 */
502 	int err;
503 	struct br2684_vcc *brvcc;
504 	struct sk_buff_head copy;
505 	struct sk_buff *skb;
506 	struct br2684_dev *brdev;
507 	struct net_device *net_dev;
508 	struct atm_backend_br2684 be;
509 
510 	if (copy_from_user(&be, arg, sizeof be))
511 		return -EFAULT;
512 	brvcc = kmalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
513 	if (!brvcc)
514 		return -ENOMEM;
515 	memset(brvcc, 0, sizeof(struct br2684_vcc));
516 	write_lock_irq(&devs_lock);
517 	net_dev = br2684_find_dev(&be.ifspec);
518 	if (net_dev == NULL) {
519 		printk(KERN_ERR
520 		    "br2684: tried to attach to non-existant device\n");
521 		err = -ENXIO;
522 		goto error;
523 	}
524 	brdev = BRPRIV(net_dev);
525 	if (atmvcc->push == NULL) {
526 		err = -EBADFD;
527 		goto error;
528 	}
529 	if (!list_empty(&brdev->brvccs)) {
530 		/* Only 1 VCC/dev right now */
531 		err = -EEXIST;
532 		goto error;
533 	}
534 	if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
535 	    be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
536 	    BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
537 	    be.min_size != 0) {
538 		err = -EINVAL;
539 		goto error;
540 	}
541 	DPRINTK("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
542 		brvcc);
543 	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
544 		unsigned char *esi = atmvcc->dev->esi;
545 		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
546 			memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
547 		else
548 			net_dev->dev_addr[2] = 1;
549 	}
550 	list_add(&brvcc->brvccs, &brdev->brvccs);
551 	write_unlock_irq(&devs_lock);
552 	brvcc->device = net_dev;
553 	brvcc->atmvcc = atmvcc;
554 	atmvcc->user_back = brvcc;
555 	brvcc->encaps = (enum br2684_encaps) be.encaps;
556 	brvcc->old_push = atmvcc->push;
557 	barrier();
558 	atmvcc->push = br2684_push;
559 	skb_queue_head_init(&copy);
560 	skb_migrate(&sk_atm(atmvcc)->sk_receive_queue, &copy);
561 	while ((skb = skb_dequeue(&copy)) != NULL) {
562 		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
563 		BRPRIV(skb->dev)->stats.rx_packets--;
564 		br2684_push(atmvcc, skb);
565 	}
566 	__module_get(THIS_MODULE);
567 	return 0;
568     error:
569 	write_unlock_irq(&devs_lock);
570 	kfree(brvcc);
571 	return err;
572 }
573 
574 static void br2684_setup(struct net_device *netdev)
575 {
576 	struct br2684_dev *brdev = BRPRIV(netdev);
577 
578 	ether_setup(netdev);
579 	brdev->net_dev = netdev;
580 
581 #ifdef FASTER_VERSION
582 	my_eth_header = netdev->hard_header;
583 	netdev->hard_header = br2684_header;
584 	my_eth_header_cache = netdev->hard_header_cache;
585 	netdev->hard_header_cache = br2684_header_cache;
586 	netdev->hard_header_len = sizeof(llc_oui_pid_pad) + ETH_HLEN;	/* 10 + 14 */
587 #endif
588 	my_eth_mac_addr = netdev->set_mac_address;
589 	netdev->set_mac_address = br2684_mac_addr;
590 	netdev->hard_start_xmit = br2684_start_xmit;
591 	netdev->get_stats = br2684_get_stats;
592 
593 	INIT_LIST_HEAD(&brdev->brvccs);
594 }
595 
596 static int br2684_create(void __user *arg)
597 {
598 	int err;
599 	struct net_device *netdev;
600 	struct br2684_dev *brdev;
601 	struct atm_newif_br2684 ni;
602 
603 	DPRINTK("br2684_create\n");
604 
605 	if (copy_from_user(&ni, arg, sizeof ni)) {
606 		return -EFAULT;
607 	}
608 	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
609 		return -EINVAL;
610 	}
611 
612 	netdev = alloc_netdev(sizeof(struct br2684_dev),
613 			      ni.ifname[0] ? ni.ifname : "nas%d",
614 			      br2684_setup);
615 	if (!netdev)
616 		return -ENOMEM;
617 
618 	brdev = BRPRIV(netdev);
619 
620 	DPRINTK("registered netdev %s\n", netdev->name);
621 	/* open, stop, do_ioctl ? */
622 	err = register_netdev(netdev);
623 	if (err < 0) {
624 		printk(KERN_ERR "br2684_create: register_netdev failed\n");
625 		free_netdev(netdev);
626 		return err;
627 	}
628 
629 	write_lock_irq(&devs_lock);
630 	brdev->number = list_empty(&br2684_devs) ? 1 :
631 	    BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
632 	list_add_tail(&brdev->br2684_devs, &br2684_devs);
633 	write_unlock_irq(&devs_lock);
634 	return 0;
635 }
636 
637 /*
638  * This handles ioctls actually performed on our vcc - we must return
639  * -ENOIOCTLCMD for any unrecognized ioctl
640  */
641 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
642 	unsigned long arg)
643 {
644 	struct atm_vcc *atmvcc = ATM_SD(sock);
645 	void __user *argp = (void __user *)arg;
646 
647 	int err;
648 	switch(cmd) {
649 	case ATM_SETBACKEND:
650 	case ATM_NEWBACKENDIF: {
651 		atm_backend_t b;
652 		err = get_user(b, (atm_backend_t __user *) argp);
653 		if (err)
654 			return -EFAULT;
655 		if (b != ATM_BACKEND_BR2684)
656 			return -ENOIOCTLCMD;
657 		if (!capable(CAP_NET_ADMIN))
658 			return -EPERM;
659 		if (cmd == ATM_SETBACKEND)
660 			return br2684_regvcc(atmvcc, argp);
661 		else
662 			return br2684_create(argp);
663 		}
664 #ifdef CONFIG_ATM_BR2684_IPFILTER
665 	case BR2684_SETFILT:
666 		if (atmvcc->push != br2684_push)
667 			return -ENOIOCTLCMD;
668 		if (!capable(CAP_NET_ADMIN))
669 			return -EPERM;
670 		err = br2684_setfilt(atmvcc, argp);
671 		return err;
672 #endif /* CONFIG_ATM_BR2684_IPFILTER */
673 	}
674 	return -ENOIOCTLCMD;
675 }
676 
677 static struct atm_ioctl br2684_ioctl_ops = {
678 	.owner	= THIS_MODULE,
679 	.ioctl	= br2684_ioctl,
680 };
681 
682 
683 #ifdef CONFIG_PROC_FS
684 static void *br2684_seq_start(struct seq_file *seq, loff_t *pos)
685 {
686 	loff_t offs = 0;
687 	struct br2684_dev *brd;
688 
689 	read_lock(&devs_lock);
690 
691 	list_for_each_entry(brd, &br2684_devs, br2684_devs) {
692 		if (offs == *pos)
693 			return brd;
694 		++offs;
695 	}
696 	return NULL;
697 }
698 
699 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t *pos)
700 {
701 	struct br2684_dev *brd = v;
702 
703 	++*pos;
704 
705 	brd = list_entry(brd->br2684_devs.next,
706 			 struct br2684_dev, br2684_devs);
707 	return (&brd->br2684_devs != &br2684_devs) ? brd : NULL;
708 }
709 
710 static void br2684_seq_stop(struct seq_file *seq, void *v)
711 {
712 	read_unlock(&devs_lock);
713 }
714 
715 static int br2684_seq_show(struct seq_file *seq, void *v)
716 {
717 	const struct br2684_dev *brdev = v;
718 	const struct net_device *net_dev = brdev->net_dev;
719 	const struct br2684_vcc *brvcc;
720 
721 	seq_printf(seq, "dev %.16s: num=%d, mac=%02X:%02X:"
722 		       "%02X:%02X:%02X:%02X (%s)\n", net_dev->name,
723 		       brdev->number,
724 		       net_dev->dev_addr[0],
725 		       net_dev->dev_addr[1],
726 		       net_dev->dev_addr[2],
727 		       net_dev->dev_addr[3],
728 		       net_dev->dev_addr[4],
729 		       net_dev->dev_addr[5],
730 		       brdev->mac_was_set ? "set" : "auto");
731 
732 	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
733 		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
734 #ifndef FASTER_VERSION
735 				    ", failed copies %u/%u"
736 #endif /* FASTER_VERSION */
737 				    "\n", brvcc->atmvcc->dev->number,
738 				    brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
739 				    (brvcc->encaps == e_llc) ? "LLC" : "VC"
740 #ifndef FASTER_VERSION
741 				    , brvcc->copies_failed
742 				    , brvcc->copies_needed
743 #endif /* FASTER_VERSION */
744 				    );
745 #ifdef CONFIG_ATM_BR2684_IPFILTER
746 #define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
747 #define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
748 			if (brvcc->filter.netmask != 0)
749 				seq_printf(seq, "    filter=%d.%d.%d.%d/"
750 						"%d.%d.%d.%d\n",
751 						bs(prefix), bs(netmask));
752 #undef bs
753 #undef b1
754 #endif /* CONFIG_ATM_BR2684_IPFILTER */
755 	}
756 	return 0;
757 }
758 
759 static struct seq_operations br2684_seq_ops = {
760 	.start = br2684_seq_start,
761 	.next  = br2684_seq_next,
762 	.stop  = br2684_seq_stop,
763 	.show  = br2684_seq_show,
764 };
765 
766 static int br2684_proc_open(struct inode *inode, struct file *file)
767 {
768 	return seq_open(file, &br2684_seq_ops);
769 }
770 
771 static struct file_operations br2684_proc_ops = {
772 	.owner   = THIS_MODULE,
773 	.open    = br2684_proc_open,
774 	.read    = seq_read,
775 	.llseek  = seq_lseek,
776 	.release = seq_release,
777 };
778 
779 extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
780 #endif
781 
782 static int __init br2684_init(void)
783 {
784 #ifdef CONFIG_PROC_FS
785 	struct proc_dir_entry *p;
786 	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
787 		return -ENOMEM;
788 	p->proc_fops = &br2684_proc_ops;
789 #endif
790 	register_atm_ioctl(&br2684_ioctl_ops);
791 	return 0;
792 }
793 
794 static void __exit br2684_exit(void)
795 {
796 	struct net_device *net_dev;
797 	struct br2684_dev *brdev;
798 	struct br2684_vcc *brvcc;
799 	deregister_atm_ioctl(&br2684_ioctl_ops);
800 
801 #ifdef CONFIG_PROC_FS
802 	remove_proc_entry("br2684", atm_proc_root);
803 #endif
804 
805 	while (!list_empty(&br2684_devs)) {
806 		net_dev = list_entry_brdev(br2684_devs.next);
807 		brdev = BRPRIV(net_dev);
808 		while (!list_empty(&brdev->brvccs)) {
809 			brvcc = list_entry_brvcc(brdev->brvccs.next);
810 			br2684_close_vcc(brvcc);
811 		}
812 
813 		list_del(&brdev->br2684_devs);
814 		unregister_netdev(net_dev);
815 		free_netdev(net_dev);
816 	}
817 }
818 
819 module_init(br2684_init);
820 module_exit(br2684_exit);
821 
822 MODULE_AUTHOR("Marcell GAL");
823 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
824 MODULE_LICENSE("GPL");
825