Linux Audio

Check our new training course

Loading...
v3.1
 
  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
 32static 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
 52static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
 53static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
 54static const unsigned char llc_oui_pid_pad[] =
 55			{ LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
 
 56static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
 57static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
 58
 59enum br2684_encaps {
 60	e_vc = BR2684_ENCAPS_VC,
 61	e_llc = BR2684_ENCAPS_LLC,
 62};
 63
 64struct br2684_vcc {
 65	struct atm_vcc *atmvcc;
 66	struct net_device *device;
 67	/* keep old push, pop functions for chaining */
 68	void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
 69	void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
 
 
 70	enum br2684_encaps encaps;
 71	struct list_head brvccs;
 72#ifdef CONFIG_ATM_BR2684_IPFILTER
 73	struct br2684_filter filter;
 74#endif /* CONFIG_ATM_BR2684_IPFILTER */
 75	unsigned copies_needed, copies_failed;
 
 76};
 77
 78struct br2684_dev {
 79	struct net_device *net_dev;
 80	struct list_head br2684_devs;
 81	int number;
 82	struct list_head brvccs;	/* one device <=> one vcc (before xmas) */
 83	int mac_was_set;
 84	enum br2684_payload payload;
 85};
 86
 87/*
 88 * This lock should be held for writing any time the list of devices or
 89 * their attached vcc's could be altered.  It should be held for reading
 90 * any time these are being queried.  Note that we sometimes need to
 91 * do read-locking under interrupt context, so write locking must block
 92 * the current CPU's interrupts
 93 */
 94static DEFINE_RWLOCK(devs_lock);
 95
 96static LIST_HEAD(br2684_devs);
 97
 98static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
 99{
100	return netdev_priv(net_dev);
101}
102
103static inline struct net_device *list_entry_brdev(const struct list_head *le)
104{
105	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
106}
107
108static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
109{
110	return (struct br2684_vcc *)(atmvcc->user_back);
111}
112
113static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
114{
115	return list_entry(le, struct br2684_vcc, brvccs);
116}
117
118/* Caller should hold read_lock(&devs_lock) */
119static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
120{
121	struct list_head *lh;
122	struct net_device *net_dev;
123	switch (s->method) {
124	case BR2684_FIND_BYNUM:
125		list_for_each(lh, &br2684_devs) {
126			net_dev = list_entry_brdev(lh);
127			if (BRPRIV(net_dev)->number == s->spec.devnum)
128				return net_dev;
129		}
130		break;
131	case BR2684_FIND_BYIFNAME:
132		list_for_each(lh, &br2684_devs) {
133			net_dev = list_entry_brdev(lh);
134			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
135				return net_dev;
136		}
137		break;
138	}
139	return NULL;
140}
141
142static int atm_dev_event(struct notifier_block *this, unsigned long event,
143		 void *arg)
144{
145	struct atm_dev *atm_dev = arg;
146	struct list_head *lh;
147	struct net_device *net_dev;
148	struct br2684_vcc *brvcc;
149	struct atm_vcc *atm_vcc;
150	unsigned long flags;
151
152	pr_debug("event=%ld dev=%p\n", event, atm_dev);
153
154	read_lock_irqsave(&devs_lock, flags);
155	list_for_each(lh, &br2684_devs) {
156		net_dev = list_entry_brdev(lh);
157
158		list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
159			atm_vcc = brvcc->atmvcc;
160			if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
161
162				if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
163					netif_carrier_off(net_dev);
164				else
165					netif_carrier_on(net_dev);
166
167			}
168		}
169	}
170	read_unlock_irqrestore(&devs_lock, flags);
171
172	return NOTIFY_DONE;
173}
174
175static struct notifier_block atm_dev_notifier = {
176	.notifier_call = atm_dev_event,
177};
178
179/* chained vcc->pop function.  Check if we should wake the netif_queue */
180static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
181{
182	struct br2684_vcc *brvcc = BR2684_VCC(vcc);
183	struct net_device *net_dev = skb->dev;
184
185	pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev);
186	brvcc->old_pop(vcc, skb);
187
188	if (!net_dev)
189		return;
190
191	if (atm_may_send(vcc, 0))
192		netif_wake_queue(net_dev);
193
194}
 
195/*
196 * Send a packet out a particular vcc.  Not to useful right now, but paves
197 * the way for multiple vcc's per itf.  Returns true if we can send,
198 * otherwise false
199 */
200static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
201			   struct br2684_vcc *brvcc)
202{
203	struct br2684_dev *brdev = BRPRIV(dev);
204	struct atm_vcc *atmvcc;
205	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
 
 
 
206
207	if (skb_headroom(skb) < minheadroom) {
208		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
209		brvcc->copies_needed++;
210		dev_kfree_skb(skb);
211		if (skb2 == NULL) {
212			brvcc->copies_failed++;
213			return 0;
214		}
215		skb = skb2;
216	}
217
218	if (brvcc->encaps == e_llc) {
219		if (brdev->payload == p_bridged) {
220			skb_push(skb, sizeof(llc_oui_pid_pad));
221			skb_copy_to_linear_data(skb, llc_oui_pid_pad,
222						sizeof(llc_oui_pid_pad));
223		} else if (brdev->payload == p_routed) {
224			unsigned short prot = ntohs(skb->protocol);
225
226			skb_push(skb, sizeof(llc_oui_ipv4));
227			switch (prot) {
228			case ETH_P_IP:
229				skb_copy_to_linear_data(skb, llc_oui_ipv4,
230							sizeof(llc_oui_ipv4));
231				break;
232			case ETH_P_IPV6:
233				skb_copy_to_linear_data(skb, llc_oui_ipv6,
234							sizeof(llc_oui_ipv6));
235				break;
236			default:
237				dev_kfree_skb(skb);
238				return 0;
239			}
240		}
241	} else { /* e_vc */
242		if (brdev->payload == p_bridged) {
243			skb_push(skb, 2);
244			memset(skb->data, 0, 2);
245		}
246	}
247	skb_debug(skb);
248
249	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
250	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
251	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
252	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
253	dev->stats.tx_packets++;
254	dev->stats.tx_bytes += skb->len;
255	atmvcc->send(atmvcc, skb);
256
257	if (!atm_may_send(atmvcc, 0)) {
 
258		netif_stop_queue(brvcc->device);
259		/*check for race with br2684_pop*/
260		if (atm_may_send(atmvcc, 0))
261			netif_start_queue(brvcc->device);
262	}
263
264	return 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
265}
266
267static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
268						   const struct br2684_dev *brdev)
269{
270	return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);	/* 1 vcc/dev right now */
271}
272
273static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
274				     struct net_device *dev)
275{
276	struct br2684_dev *brdev = BRPRIV(dev);
277	struct br2684_vcc *brvcc;
 
 
278
279	pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
280	read_lock(&devs_lock);
281	brvcc = pick_outgoing_vcc(skb, brdev);
282	if (brvcc == NULL) {
283		pr_debug("no vcc attached to dev %s\n", dev->name);
284		dev->stats.tx_errors++;
285		dev->stats.tx_carrier_errors++;
286		/* netif_stop_queue(dev); */
287		dev_kfree_skb(skb);
288		read_unlock(&devs_lock);
289		return NETDEV_TX_OK;
 
 
 
 
 
 
 
 
 
 
290	}
 
 
 
 
 
 
 
291	if (!br2684_xmit_vcc(skb, dev, brvcc)) {
292		/*
293		 * We should probably use netif_*_queue() here, but that
294		 * involves added complication.  We need to walk before
295		 * we can run.
296		 *
297		 * Don't free here! this pointer might be no longer valid!
298		 */
299		dev->stats.tx_errors++;
300		dev->stats.tx_fifo_errors++;
301	}
 
 
 
302	read_unlock(&devs_lock);
303	return NETDEV_TX_OK;
304}
305
306/*
307 * We remember when the MAC gets set, so we don't override it later with
308 * the ESI of the ATM card of the first VC
309 */
310static int br2684_mac_addr(struct net_device *dev, void *p)
311{
312	int err = eth_mac_addr(dev, p);
313	if (!err)
314		BRPRIV(dev)->mac_was_set = 1;
315	return err;
316}
317
318#ifdef CONFIG_ATM_BR2684_IPFILTER
319/* this IOCTL is experimental. */
320static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
321{
322	struct br2684_vcc *brvcc;
323	struct br2684_filter_set fs;
324
325	if (copy_from_user(&fs, arg, sizeof fs))
326		return -EFAULT;
327	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
328		/*
329		 * This is really a per-vcc thing, but we can also search
330		 * by device.
331		 */
332		struct br2684_dev *brdev;
333		read_lock(&devs_lock);
334		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
335		if (brdev == NULL || list_empty(&brdev->brvccs) ||
336		    brdev->brvccs.next != brdev->brvccs.prev)	/* >1 VCC */
337			brvcc = NULL;
338		else
339			brvcc = list_entry_brvcc(brdev->brvccs.next);
340		read_unlock(&devs_lock);
341		if (brvcc == NULL)
342			return -ESRCH;
343	} else
344		brvcc = BR2684_VCC(atmvcc);
345	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
346	return 0;
347}
348
349/* Returns 1 if packet should be dropped */
350static inline int
351packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
352{
353	if (brvcc->filter.netmask == 0)
354		return 0;	/* no filter in place */
355	if (type == htons(ETH_P_IP) &&
356	    (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
357	     netmask) == brvcc->filter.prefix)
358		return 0;
359	if (type == htons(ETH_P_ARP))
360		return 0;
361	/*
362	 * TODO: we should probably filter ARPs too.. don't want to have
363	 * them returning values that don't make sense, or is that ok?
364	 */
365	return 1;		/* drop */
366}
367#endif /* CONFIG_ATM_BR2684_IPFILTER */
368
369static void br2684_close_vcc(struct br2684_vcc *brvcc)
370{
371	pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
372	write_lock_irq(&devs_lock);
373	list_del(&brvcc->brvccs);
374	write_unlock_irq(&devs_lock);
375	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
 
376	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
 
377	kfree(brvcc);
378	module_put(THIS_MODULE);
379}
380
381/* when AAL5 PDU comes in: */
382static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
383{
384	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
385	struct net_device *net_dev = brvcc->device;
386	struct br2684_dev *brdev = BRPRIV(net_dev);
387
388	pr_debug("\n");
389
390	if (unlikely(skb == NULL)) {
391		/* skb==NULL means VCC is being destroyed */
392		br2684_close_vcc(brvcc);
393		if (list_empty(&brdev->brvccs)) {
394			write_lock_irq(&devs_lock);
395			list_del(&brdev->br2684_devs);
396			write_unlock_irq(&devs_lock);
397			unregister_netdev(net_dev);
398			free_netdev(net_dev);
399		}
400		return;
401	}
402
403	skb_debug(skb);
404	atm_return(atmvcc, skb->truesize);
405	pr_debug("skb from brdev %p\n", brdev);
406	if (brvcc->encaps == e_llc) {
407
408		if (skb->len > 7 && skb->data[7] == 0x01)
409			__skb_trim(skb, skb->len - 4);
410
411		/* accept packets that have "ipv[46]" in the snap header */
412		if ((skb->len >= (sizeof(llc_oui_ipv4))) &&
413		    (memcmp(skb->data, llc_oui_ipv4,
414			    sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
415			if (memcmp(skb->data + 6, ethertype_ipv6,
416				   sizeof(ethertype_ipv6)) == 0)
417				skb->protocol = htons(ETH_P_IPV6);
418			else if (memcmp(skb->data + 6, ethertype_ipv4,
419					sizeof(ethertype_ipv4)) == 0)
420				skb->protocol = htons(ETH_P_IP);
421			else
422				goto error;
423			skb_pull(skb, sizeof(llc_oui_ipv4));
424			skb_reset_network_header(skb);
425			skb->pkt_type = PACKET_HOST;
426		/*
427		 * Let us waste some time for checking the encapsulation.
428		 * Note, that only 7 char is checked so frames with a valid FCS
429		 * are also accepted (but FCS is not checked of course).
430		 */
431		} else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
432			   (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
433			skb_pull(skb, sizeof(llc_oui_pid_pad));
434			skb->protocol = eth_type_trans(skb, net_dev);
435		} else
436			goto error;
437
438	} else { /* e_vc */
439		if (brdev->payload == p_routed) {
440			struct iphdr *iph;
441
442			skb_reset_network_header(skb);
443			iph = ip_hdr(skb);
444			if (iph->version == 4)
445				skb->protocol = htons(ETH_P_IP);
446			else if (iph->version == 6)
447				skb->protocol = htons(ETH_P_IPV6);
448			else
449				goto error;
450			skb->pkt_type = PACKET_HOST;
451		} else { /* p_bridged */
452			/* first 2 chars should be 0 */
453			if (*((u16 *) (skb->data)) != 0)
454				goto error;
455			skb_pull(skb, BR2684_PAD_LEN);
456			skb->protocol = eth_type_trans(skb, net_dev);
457		}
458	}
459
460#ifdef CONFIG_ATM_BR2684_IPFILTER
461	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
462		goto dropped;
463#endif /* CONFIG_ATM_BR2684_IPFILTER */
464	skb->dev = net_dev;
465	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
466	pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
467	skb_debug(skb);
468	/* sigh, interface is down? */
469	if (unlikely(!(net_dev->flags & IFF_UP)))
470		goto dropped;
471	net_dev->stats.rx_packets++;
472	net_dev->stats.rx_bytes += skb->len;
473	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
474	netif_rx(skb);
475	return;
476
477dropped:
478	net_dev->stats.rx_dropped++;
479	goto free_skb;
480error:
481	net_dev->stats.rx_errors++;
482free_skb:
483	dev_kfree_skb(skb);
484}
485
486/*
487 * Assign a vcc to a dev
488 * Note: we do not have explicit unassign, but look at _push()
489 */
490static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
491{
492	struct sk_buff_head queue;
493	int err;
494	struct br2684_vcc *brvcc;
495	struct sk_buff *skb, *tmp;
496	struct sk_buff_head *rq;
497	struct br2684_dev *brdev;
498	struct net_device *net_dev;
499	struct atm_backend_br2684 be;
500	unsigned long flags;
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	__skb_queue_head_init(&queue);
554	rq = &sk_atm(atmvcc)->sk_receive_queue;
555
556	spin_lock_irqsave(&rq->lock, flags);
557	skb_queue_splice_init(rq, &queue);
558	spin_unlock_irqrestore(&rq->lock, flags);
559
560	skb_queue_walk_safe(&queue, skb, tmp) {
561		struct net_device *dev;
562
563		br2684_push(atmvcc, skb);
564		dev = skb->dev;
565
566		dev->stats.rx_bytes -= skb->len;
567		dev->stats.rx_packets--;
568	}
569
570	/* initialize netdev carrier state */
571	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
572		netif_carrier_off(net_dev);
573	else
574		netif_carrier_on(net_dev);
575
576	__module_get(THIS_MODULE);
 
 
 
 
577	return 0;
578
579error:
580	write_unlock_irq(&devs_lock);
581	kfree(brvcc);
582	return err;
583}
584
585static const struct net_device_ops br2684_netdev_ops = {
586	.ndo_start_xmit 	= br2684_start_xmit,
587	.ndo_set_mac_address	= br2684_mac_addr,
588	.ndo_change_mtu		= eth_change_mtu,
589	.ndo_validate_addr	= eth_validate_addr,
590};
591
592static const struct net_device_ops br2684_netdev_ops_routed = {
593	.ndo_start_xmit 	= br2684_start_xmit,
594	.ndo_set_mac_address	= br2684_mac_addr,
595	.ndo_change_mtu		= eth_change_mtu
596};
597
598static void br2684_setup(struct net_device *netdev)
599{
600	struct br2684_dev *brdev = BRPRIV(netdev);
601
602	ether_setup(netdev);
 
603	brdev->net_dev = netdev;
604
605	netdev->netdev_ops = &br2684_netdev_ops;
606
607	INIT_LIST_HEAD(&brdev->brvccs);
608}
609
610static void br2684_setup_routed(struct net_device *netdev)
611{
612	struct br2684_dev *brdev = BRPRIV(netdev);
613
614	brdev->net_dev = netdev;
615	netdev->hard_header_len = 0;
616	netdev->netdev_ops = &br2684_netdev_ops_routed;
617	netdev->addr_len = 0;
618	netdev->mtu = 1500;
 
 
619	netdev->type = ARPHRD_PPP;
620	netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
621	netdev->tx_queue_len = 100;
622	INIT_LIST_HEAD(&brdev->brvccs);
623}
624
625static int br2684_create(void __user *arg)
626{
627	int err;
628	struct net_device *netdev;
629	struct br2684_dev *brdev;
630	struct atm_newif_br2684 ni;
631	enum br2684_payload payload;
632
633	pr_debug("\n");
634
635	if (copy_from_user(&ni, arg, sizeof ni))
636		return -EFAULT;
637
638	if (ni.media & BR2684_FLAG_ROUTED)
639		payload = p_routed;
640	else
641		payload = p_bridged;
642	ni.media &= 0xffff;	/* strip flags */
643
644	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500)
645		return -EINVAL;
646
647	netdev = alloc_netdev(sizeof(struct br2684_dev),
648			      ni.ifname[0] ? ni.ifname : "nas%d",
649			      (payload == p_routed) ?
650			      br2684_setup_routed : br2684_setup);
651	if (!netdev)
652		return -ENOMEM;
653
654	brdev = BRPRIV(netdev);
655
656	pr_debug("registered netdev %s\n", netdev->name);
657	/* open, stop, do_ioctl ? */
658	err = register_netdev(netdev);
659	if (err < 0) {
660		pr_err("register_netdev failed\n");
661		free_netdev(netdev);
662		return err;
663	}
664
665	write_lock_irq(&devs_lock);
666
667	brdev->payload = payload;
668
669	if (list_empty(&br2684_devs)) {
670		/* 1st br2684 device */
671		brdev->number = 1;
672	} else
673		brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
674
675	list_add_tail(&brdev->br2684_devs, &br2684_devs);
676	write_unlock_irq(&devs_lock);
677	return 0;
678}
679
680/*
681 * This handles ioctls actually performed on our vcc - we must return
682 * -ENOIOCTLCMD for any unrecognized ioctl
683 */
684static int br2684_ioctl(struct socket *sock, unsigned int cmd,
685			unsigned long arg)
686{
687	struct atm_vcc *atmvcc = ATM_SD(sock);
688	void __user *argp = (void __user *)arg;
689	atm_backend_t b;
690
691	int err;
692	switch (cmd) {
693	case ATM_SETBACKEND:
694	case ATM_NEWBACKENDIF:
695		err = get_user(b, (atm_backend_t __user *) argp);
696		if (err)
697			return -EFAULT;
698		if (b != ATM_BACKEND_BR2684)
699			return -ENOIOCTLCMD;
700		if (!capable(CAP_NET_ADMIN))
701			return -EPERM;
702		if (cmd == ATM_SETBACKEND)
 
 
703			return br2684_regvcc(atmvcc, argp);
704		else
705			return br2684_create(argp);
 
706#ifdef CONFIG_ATM_BR2684_IPFILTER
707	case BR2684_SETFILT:
708		if (atmvcc->push != br2684_push)
709			return -ENOIOCTLCMD;
710		if (!capable(CAP_NET_ADMIN))
711			return -EPERM;
712		err = br2684_setfilt(atmvcc, argp);
713
714		return err;
715#endif /* CONFIG_ATM_BR2684_IPFILTER */
716	}
717	return -ENOIOCTLCMD;
718}
719
720static struct atm_ioctl br2684_ioctl_ops = {
721	.owner = THIS_MODULE,
722	.ioctl = br2684_ioctl,
723};
724
725#ifdef CONFIG_PROC_FS
726static void *br2684_seq_start(struct seq_file *seq, loff_t * pos)
727	__acquires(devs_lock)
728{
729	read_lock(&devs_lock);
730	return seq_list_start(&br2684_devs, *pos);
731}
732
733static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t * pos)
734{
735	return seq_list_next(v, &br2684_devs, pos);
736}
737
738static void br2684_seq_stop(struct seq_file *seq, void *v)
739	__releases(devs_lock)
740{
741	read_unlock(&devs_lock);
742}
743
744static int br2684_seq_show(struct seq_file *seq, void *v)
745{
746	const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
747						    br2684_devs);
748	const struct net_device *net_dev = brdev->net_dev;
749	const struct br2684_vcc *brvcc;
750
751	seq_printf(seq, "dev %.16s: num=%d, mac=%pM (%s)\n",
752		   net_dev->name,
753		   brdev->number,
754		   net_dev->dev_addr,
755		   brdev->mac_was_set ? "set" : "auto");
756
757	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
758		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
759			   ", failed copies %u/%u"
760			   "\n", brvcc->atmvcc->dev->number,
761			   brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
762			   (brvcc->encaps == e_llc) ? "LLC" : "VC",
763			   (brdev->payload == p_bridged) ? "bridged" : "routed",
764			   brvcc->copies_failed, brvcc->copies_needed);
765#ifdef CONFIG_ATM_BR2684_IPFILTER
766#define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
767#define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
768		if (brvcc->filter.netmask != 0)
769			seq_printf(seq, "    filter=%d.%d.%d.%d/"
770				   "%d.%d.%d.%d\n", bs(prefix), bs(netmask));
771#undef bs
772#undef b1
773#endif /* CONFIG_ATM_BR2684_IPFILTER */
774	}
775	return 0;
776}
777
778static const struct seq_operations br2684_seq_ops = {
779	.start = br2684_seq_start,
780	.next = br2684_seq_next,
781	.stop = br2684_seq_stop,
782	.show = br2684_seq_show,
783};
784
785static int br2684_proc_open(struct inode *inode, struct file *file)
786{
787	return seq_open(file, &br2684_seq_ops);
788}
789
790static const struct file_operations br2684_proc_ops = {
791	.owner = THIS_MODULE,
792	.open = br2684_proc_open,
793	.read = seq_read,
794	.llseek = seq_lseek,
795	.release = seq_release,
796};
797
798extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
799#endif /* CONFIG_PROC_FS */
800
801static int __init br2684_init(void)
802{
803#ifdef CONFIG_PROC_FS
804	struct proc_dir_entry *p;
805	p = proc_create("br2684", 0, atm_proc_root, &br2684_proc_ops);
806	if (p == NULL)
807		return -ENOMEM;
808#endif
809	register_atm_ioctl(&br2684_ioctl_ops);
810	register_atmdevice_notifier(&atm_dev_notifier);
811	return 0;
812}
813
814static void __exit br2684_exit(void)
815{
816	struct net_device *net_dev;
817	struct br2684_dev *brdev;
818	struct br2684_vcc *brvcc;
819	deregister_atm_ioctl(&br2684_ioctl_ops);
820
821#ifdef CONFIG_PROC_FS
822	remove_proc_entry("br2684", atm_proc_root);
823#endif
824
825
826	unregister_atmdevice_notifier(&atm_dev_notifier);
827
828	while (!list_empty(&br2684_devs)) {
829		net_dev = list_entry_brdev(br2684_devs.next);
830		brdev = BRPRIV(net_dev);
831		while (!list_empty(&brdev->brvccs)) {
832			brvcc = list_entry_brvcc(brdev->brvccs.next);
833			br2684_close_vcc(brvcc);
834		}
835
836		list_del(&brdev->br2684_devs);
837		unregister_netdev(net_dev);
838		free_netdev(net_dev);
839	}
840}
841
842module_init(br2684_init);
843module_exit(br2684_exit);
844
845MODULE_AUTHOR("Marcell GAL");
846MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
847MODULE_LICENSE("GPL");
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Ethernet netdevice using ATM AAL5 as underlying carrier
  4 * (RFC1483 obsoleted by RFC2684) for Linux
  5 *
  6 * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
  7 *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
  8 */
  9
 10#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
 11
 12#include <linux/module.h>
 13#include <linux/init.h>
 14#include <linux/kernel.h>
 15#include <linux/list.h>
 16#include <linux/netdevice.h>
 17#include <linux/skbuff.h>
 18#include <linux/etherdevice.h>
 19#include <linux/rtnetlink.h>
 20#include <linux/ip.h>
 21#include <linux/uaccess.h>
 22#include <linux/slab.h>
 23#include <net/arp.h>
 24#include <linux/atm.h>
 25#include <linux/atmdev.h>
 26#include <linux/capability.h>
 27#include <linux/seq_file.h>
 28
 29#include <linux/atmbr2684.h>
 30
 31#include "common.h"
 32
 33static void skb_debug(const struct sk_buff *skb)
 34{
 35#ifdef SKB_DEBUG
 36#define NUM2PRINT 50
 37	print_hex_dump(KERN_DEBUG, "br2684: skb: ", DUMP_OFFSET,
 38		       16, 1, skb->data, min(NUM2PRINT, skb->len), true);
 39#endif
 40}
 41
 42#define BR2684_ETHERTYPE_LEN	2
 43#define BR2684_PAD_LEN		2
 44
 45#define LLC		0xaa, 0xaa, 0x03
 46#define SNAP_BRIDGED	0x00, 0x80, 0xc2
 47#define SNAP_ROUTED	0x00, 0x00, 0x00
 48#define PID_ETHERNET	0x00, 0x07
 49#define ETHERTYPE_IPV4	0x08, 0x00
 50#define ETHERTYPE_IPV6	0x86, 0xdd
 51#define PAD_BRIDGED	0x00, 0x00
 52
 53static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
 54static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
 55static const unsigned char llc_oui_pid_pad[] =
 56			{ LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
 57static const unsigned char pad[] = { PAD_BRIDGED };
 58static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
 59static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
 60
 61enum br2684_encaps {
 62	e_vc = BR2684_ENCAPS_VC,
 63	e_llc = BR2684_ENCAPS_LLC,
 64};
 65
 66struct br2684_vcc {
 67	struct atm_vcc *atmvcc;
 68	struct net_device *device;
 69	/* keep old push, pop functions for chaining */
 70	void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
 71	void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
 72	void (*old_release_cb)(struct atm_vcc *vcc);
 73	struct module *old_owner;
 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	unsigned int copies_needed, copies_failed;
 80	atomic_t qspace;
 81};
 82
 83struct 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	int mac_was_set;
 89	enum br2684_payload payload;
 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 interrupting context, so write locking must block
 97 * the current CPU's interrupts.
 98 */
 99static DEFINE_RWLOCK(devs_lock);
100
101static LIST_HEAD(br2684_devs);
102
103static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
104{
105	return netdev_priv(net_dev);
106}
107
108static 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
113static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
114{
115	return (struct br2684_vcc *)(atmvcc->user_back);
116}
117
118static 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) */
124static 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
147static int atm_dev_event(struct notifier_block *this, unsigned long event,
148		 void *arg)
149{
150	struct atm_dev *atm_dev = arg;
151	struct list_head *lh;
152	struct net_device *net_dev;
153	struct br2684_vcc *brvcc;
154	struct atm_vcc *atm_vcc;
155	unsigned long flags;
156
157	pr_debug("event=%ld dev=%p\n", event, atm_dev);
158
159	read_lock_irqsave(&devs_lock, flags);
160	list_for_each(lh, &br2684_devs) {
161		net_dev = list_entry_brdev(lh);
162
163		list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
164			atm_vcc = brvcc->atmvcc;
165			if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
166
167				if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
168					netif_carrier_off(net_dev);
169				else
170					netif_carrier_on(net_dev);
171
172			}
173		}
174	}
175	read_unlock_irqrestore(&devs_lock, flags);
176
177	return NOTIFY_DONE;
178}
179
180static struct notifier_block atm_dev_notifier = {
181	.notifier_call = atm_dev_event,
182};
183
184/* chained vcc->pop function.  Check if we should wake the netif_queue */
185static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
186{
187	struct br2684_vcc *brvcc = BR2684_VCC(vcc);
 
188
189	pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
190	brvcc->old_pop(vcc, skb);
191
192	/* If the queue space just went up from zero, wake */
193	if (atomic_inc_return(&brvcc->qspace) == 1)
194		netif_wake_queue(brvcc->device);
 
 
 
195}
196
197/*
198 * Send a packet out a particular vcc.  Not to useful right now, but paves
199 * the way for multiple vcc's per itf.  Returns true if we can send,
200 * otherwise false
201 */
202static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
203			   struct br2684_vcc *brvcc)
204{
205	struct br2684_dev *brdev = BRPRIV(dev);
206	struct atm_vcc *atmvcc;
207	int minheadroom = (brvcc->encaps == e_llc) ?
208		((brdev->payload == p_bridged) ?
209			sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) :
210		((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0);
211
212	if (skb_headroom(skb) < minheadroom) {
213		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
214		brvcc->copies_needed++;
215		dev_kfree_skb(skb);
216		if (skb2 == NULL) {
217			brvcc->copies_failed++;
218			return 0;
219		}
220		skb = skb2;
221	}
222
223	if (brvcc->encaps == e_llc) {
224		if (brdev->payload == p_bridged) {
225			skb_push(skb, sizeof(llc_oui_pid_pad));
226			skb_copy_to_linear_data(skb, llc_oui_pid_pad,
227						sizeof(llc_oui_pid_pad));
228		} else if (brdev->payload == p_routed) {
229			unsigned short prot = ntohs(skb->protocol);
230
231			skb_push(skb, sizeof(llc_oui_ipv4));
232			switch (prot) {
233			case ETH_P_IP:
234				skb_copy_to_linear_data(skb, llc_oui_ipv4,
235							sizeof(llc_oui_ipv4));
236				break;
237			case ETH_P_IPV6:
238				skb_copy_to_linear_data(skb, llc_oui_ipv6,
239							sizeof(llc_oui_ipv6));
240				break;
241			default:
242				dev_kfree_skb(skb);
243				return 0;
244			}
245		}
246	} else { /* e_vc */
247		if (brdev->payload == p_bridged) {
248			skb_push(skb, 2);
249			memset(skb->data, 0, 2);
250		}
251	}
252	skb_debug(skb);
253
254	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
255	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
256	atm_account_tx(atmvcc, skb);
 
257	dev->stats.tx_packets++;
258	dev->stats.tx_bytes += skb->len;
 
259
260	if (atomic_dec_return(&brvcc->qspace) < 1) {
261		/* No more please! */
262		netif_stop_queue(brvcc->device);
263		/* We might have raced with br2684_pop() */
264		if (unlikely(atomic_read(&brvcc->qspace) > 0))
265			netif_wake_queue(brvcc->device);
266	}
267
268	/* If this fails immediately, the skb will be freed and br2684_pop()
269	   will wake the queue if appropriate. Just return an error so that
270	   the stats are updated correctly */
271	return !atmvcc->send(atmvcc, skb);
272}
273
274static void br2684_release_cb(struct atm_vcc *atmvcc)
275{
276	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
277
278	if (atomic_read(&brvcc->qspace) > 0)
279		netif_wake_queue(brvcc->device);
280
281	if (brvcc->old_release_cb)
282		brvcc->old_release_cb(atmvcc);
283}
284
285static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
286						   const struct br2684_dev *brdev)
287{
288	return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);	/* 1 vcc/dev right now */
289}
290
291static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
292				     struct net_device *dev)
293{
294	struct br2684_dev *brdev = BRPRIV(dev);
295	struct br2684_vcc *brvcc;
296	struct atm_vcc *atmvcc;
297	netdev_tx_t ret = NETDEV_TX_OK;
298
299	pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
300	read_lock(&devs_lock);
301	brvcc = pick_outgoing_vcc(skb, brdev);
302	if (brvcc == NULL) {
303		pr_debug("no vcc attached to dev %s\n", dev->name);
304		dev->stats.tx_errors++;
305		dev->stats.tx_carrier_errors++;
306		/* netif_stop_queue(dev); */
307		dev_kfree_skb(skb);
308		goto out_devs;
309	}
310	atmvcc = brvcc->atmvcc;
311
312	bh_lock_sock(sk_atm(atmvcc));
313
314	if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
315	    test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
316	    !test_bit(ATM_VF_READY, &atmvcc->flags)) {
317		dev->stats.tx_dropped++;
318		dev_kfree_skb(skb);
319		goto out;
320	}
321
322	if (sock_owned_by_user(sk_atm(atmvcc))) {
323		netif_stop_queue(brvcc->device);
324		ret = NETDEV_TX_BUSY;
325		goto out;
326	}
327
328	if (!br2684_xmit_vcc(skb, dev, brvcc)) {
329		/*
330		 * We should probably use netif_*_queue() here, but that
331		 * involves added complication.  We need to walk before
332		 * we can run.
333		 *
334		 * Don't free here! this pointer might be no longer valid!
335		 */
336		dev->stats.tx_errors++;
337		dev->stats.tx_fifo_errors++;
338	}
339 out:
340	bh_unlock_sock(sk_atm(atmvcc));
341 out_devs:
342	read_unlock(&devs_lock);
343	return ret;
344}
345
346/*
347 * We remember when the MAC gets set, so we don't override it later with
348 * the ESI of the ATM card of the first VC
349 */
350static int br2684_mac_addr(struct net_device *dev, void *p)
351{
352	int err = eth_mac_addr(dev, p);
353	if (!err)
354		BRPRIV(dev)->mac_was_set = 1;
355	return err;
356}
357
358#ifdef CONFIG_ATM_BR2684_IPFILTER
359/* this IOCTL is experimental. */
360static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
361{
362	struct br2684_vcc *brvcc;
363	struct br2684_filter_set fs;
364
365	if (copy_from_user(&fs, arg, sizeof fs))
366		return -EFAULT;
367	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
368		/*
369		 * This is really a per-vcc thing, but we can also search
370		 * by device.
371		 */
372		struct br2684_dev *brdev;
373		read_lock(&devs_lock);
374		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
375		if (brdev == NULL || list_empty(&brdev->brvccs) ||
376		    brdev->brvccs.next != brdev->brvccs.prev)	/* >1 VCC */
377			brvcc = NULL;
378		else
379			brvcc = list_entry_brvcc(brdev->brvccs.next);
380		read_unlock(&devs_lock);
381		if (brvcc == NULL)
382			return -ESRCH;
383	} else
384		brvcc = BR2684_VCC(atmvcc);
385	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
386	return 0;
387}
388
389/* Returns 1 if packet should be dropped */
390static inline int
391packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
392{
393	if (brvcc->filter.netmask == 0)
394		return 0;	/* no filter in place */
395	if (type == htons(ETH_P_IP) &&
396	    (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
397	     netmask) == brvcc->filter.prefix)
398		return 0;
399	if (type == htons(ETH_P_ARP))
400		return 0;
401	/*
402	 * TODO: we should probably filter ARPs too.. don't want to have
403	 * them returning values that don't make sense, or is that ok?
404	 */
405	return 1;		/* drop */
406}
407#endif /* CONFIG_ATM_BR2684_IPFILTER */
408
409static void br2684_close_vcc(struct br2684_vcc *brvcc)
410{
411	pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
412	write_lock_irq(&devs_lock);
413	list_del(&brvcc->brvccs);
414	write_unlock_irq(&devs_lock);
415	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
416	brvcc->atmvcc->release_cb = brvcc->old_release_cb;
417	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
418	module_put(brvcc->old_owner);
419	kfree(brvcc);
 
420}
421
422/* when AAL5 PDU comes in: */
423static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
424{
425	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
426	struct net_device *net_dev = brvcc->device;
427	struct br2684_dev *brdev = BRPRIV(net_dev);
428
429	pr_debug("\n");
430
431	if (unlikely(skb == NULL)) {
432		/* skb==NULL means VCC is being destroyed */
433		br2684_close_vcc(brvcc);
434		if (list_empty(&brdev->brvccs)) {
435			write_lock_irq(&devs_lock);
436			list_del(&brdev->br2684_devs);
437			write_unlock_irq(&devs_lock);
438			unregister_netdev(net_dev);
439			free_netdev(net_dev);
440		}
441		return;
442	}
443
444	skb_debug(skb);
445	atm_return(atmvcc, skb->truesize);
446	pr_debug("skb from brdev %p\n", brdev);
447	if (brvcc->encaps == e_llc) {
448
449		if (skb->len > 7 && skb->data[7] == 0x01)
450			__skb_trim(skb, skb->len - 4);
451
452		/* accept packets that have "ipv[46]" in the snap header */
453		if ((skb->len >= (sizeof(llc_oui_ipv4))) &&
454		    (memcmp(skb->data, llc_oui_ipv4,
455			    sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
456			if (memcmp(skb->data + 6, ethertype_ipv6,
457				   sizeof(ethertype_ipv6)) == 0)
458				skb->protocol = htons(ETH_P_IPV6);
459			else if (memcmp(skb->data + 6, ethertype_ipv4,
460					sizeof(ethertype_ipv4)) == 0)
461				skb->protocol = htons(ETH_P_IP);
462			else
463				goto error;
464			skb_pull(skb, sizeof(llc_oui_ipv4));
465			skb_reset_network_header(skb);
466			skb->pkt_type = PACKET_HOST;
467		/*
468		 * Let us waste some time for checking the encapsulation.
469		 * Note, that only 7 char is checked so frames with a valid FCS
470		 * are also accepted (but FCS is not checked of course).
471		 */
472		} else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
473			   (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
474			skb_pull(skb, sizeof(llc_oui_pid_pad));
475			skb->protocol = eth_type_trans(skb, net_dev);
476		} else
477			goto error;
478
479	} else { /* e_vc */
480		if (brdev->payload == p_routed) {
481			struct iphdr *iph;
482
483			skb_reset_network_header(skb);
484			iph = ip_hdr(skb);
485			if (iph->version == 4)
486				skb->protocol = htons(ETH_P_IP);
487			else if (iph->version == 6)
488				skb->protocol = htons(ETH_P_IPV6);
489			else
490				goto error;
491			skb->pkt_type = PACKET_HOST;
492		} else { /* p_bridged */
493			/* first 2 chars should be 0 */
494			if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0)
495				goto error;
496			skb_pull(skb, BR2684_PAD_LEN);
497			skb->protocol = eth_type_trans(skb, net_dev);
498		}
499	}
500
501#ifdef CONFIG_ATM_BR2684_IPFILTER
502	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
503		goto dropped;
504#endif /* CONFIG_ATM_BR2684_IPFILTER */
505	skb->dev = net_dev;
506	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
507	pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
508	skb_debug(skb);
509	/* sigh, interface is down? */
510	if (unlikely(!(net_dev->flags & IFF_UP)))
511		goto dropped;
512	net_dev->stats.rx_packets++;
513	net_dev->stats.rx_bytes += skb->len;
514	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
515	netif_rx(skb);
516	return;
517
518dropped:
519	net_dev->stats.rx_dropped++;
520	goto free_skb;
521error:
522	net_dev->stats.rx_errors++;
523free_skb:
524	dev_kfree_skb(skb);
525}
526
527/*
528 * Assign a vcc to a dev
529 * Note: we do not have explicit unassign, but look at _push()
530 */
531static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
532{
 
 
533	struct br2684_vcc *brvcc;
 
 
534	struct br2684_dev *brdev;
535	struct net_device *net_dev;
536	struct atm_backend_br2684 be;
537	int err;
538
539	if (copy_from_user(&be, arg, sizeof be))
540		return -EFAULT;
541	brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
542	if (!brvcc)
543		return -ENOMEM;
544	/*
545	 * Allow two packets in the ATM queue. One actually being sent, and one
546	 * for the ATM 'TX done' handler to send. It shouldn't take long to get
547	 * the next one from the netdev queue, when we need it. More than that
548	 * would be bufferbloat.
549	 */
550	atomic_set(&brvcc->qspace, 2);
551	write_lock_irq(&devs_lock);
552	net_dev = br2684_find_dev(&be.ifspec);
553	if (net_dev == NULL) {
554		pr_err("tried to attach to non-existent device\n");
555		err = -ENXIO;
556		goto error;
557	}
558	brdev = BRPRIV(net_dev);
559	if (atmvcc->push == NULL) {
560		err = -EBADFD;
561		goto error;
562	}
563	if (!list_empty(&brdev->brvccs)) {
564		/* Only 1 VCC/dev right now */
565		err = -EEXIST;
566		goto error;
567	}
568	if (be.fcs_in != BR2684_FCSIN_NO ||
569	    be.fcs_out != BR2684_FCSOUT_NO ||
570	    be.fcs_auto || be.has_vpiid || be.send_padding ||
571	    (be.encaps != BR2684_ENCAPS_VC &&
572	     be.encaps != BR2684_ENCAPS_LLC) ||
573	    be.min_size != 0) {
574		err = -EINVAL;
575		goto error;
576	}
577	pr_debug("vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps, brvcc);
578	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
579		unsigned char *esi = atmvcc->dev->esi;
580		const u8 one = 1;
581
582		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
583			dev_addr_set(net_dev, esi);
584		else
585			dev_addr_mod(net_dev, 2, &one, 1);
586	}
587	list_add(&brvcc->brvccs, &brdev->brvccs);
588	write_unlock_irq(&devs_lock);
589	brvcc->device = net_dev;
590	brvcc->atmvcc = atmvcc;
591	atmvcc->user_back = brvcc;
592	brvcc->encaps = (enum br2684_encaps)be.encaps;
593	brvcc->old_push = atmvcc->push;
594	brvcc->old_pop = atmvcc->pop;
595	brvcc->old_release_cb = atmvcc->release_cb;
596	brvcc->old_owner = atmvcc->owner;
597	barrier();
598	atmvcc->push = br2684_push;
599	atmvcc->pop = br2684_pop;
600	atmvcc->release_cb = br2684_release_cb;
601	atmvcc->owner = THIS_MODULE;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
602
603	/* initialize netdev carrier state */
604	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
605		netif_carrier_off(net_dev);
606	else
607		netif_carrier_on(net_dev);
608
609	__module_get(THIS_MODULE);
610
611	/* re-process everything received between connection setup and
612	   backend setup */
613	vcc_process_recv_queue(atmvcc);
614	return 0;
615
616error:
617	write_unlock_irq(&devs_lock);
618	kfree(brvcc);
619	return err;
620}
621
622static const struct net_device_ops br2684_netdev_ops = {
623	.ndo_start_xmit 	= br2684_start_xmit,
624	.ndo_set_mac_address	= br2684_mac_addr,
 
625	.ndo_validate_addr	= eth_validate_addr,
626};
627
628static const struct net_device_ops br2684_netdev_ops_routed = {
629	.ndo_start_xmit 	= br2684_start_xmit,
630	.ndo_set_mac_address	= br2684_mac_addr,
 
631};
632
633static void br2684_setup(struct net_device *netdev)
634{
635	struct br2684_dev *brdev = BRPRIV(netdev);
636
637	ether_setup(netdev);
638	netdev->hard_header_len += sizeof(llc_oui_pid_pad); /* worst case */
639	brdev->net_dev = netdev;
640
641	netdev->netdev_ops = &br2684_netdev_ops;
642
643	INIT_LIST_HEAD(&brdev->brvccs);
644}
645
646static void br2684_setup_routed(struct net_device *netdev)
647{
648	struct br2684_dev *brdev = BRPRIV(netdev);
649
650	brdev->net_dev = netdev;
651	netdev->hard_header_len = sizeof(llc_oui_ipv4); /* worst case */
652	netdev->netdev_ops = &br2684_netdev_ops_routed;
653	netdev->addr_len = 0;
654	netdev->mtu = ETH_DATA_LEN;
655	netdev->min_mtu = 0;
656	netdev->max_mtu = ETH_MAX_MTU;
657	netdev->type = ARPHRD_PPP;
658	netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
659	netdev->tx_queue_len = 100;
660	INIT_LIST_HEAD(&brdev->brvccs);
661}
662
663static int br2684_create(void __user *arg)
664{
665	int err;
666	struct net_device *netdev;
667	struct br2684_dev *brdev;
668	struct atm_newif_br2684 ni;
669	enum br2684_payload payload;
670
671	pr_debug("\n");
672
673	if (copy_from_user(&ni, arg, sizeof ni))
674		return -EFAULT;
675
676	if (ni.media & BR2684_FLAG_ROUTED)
677		payload = p_routed;
678	else
679		payload = p_bridged;
680	ni.media &= 0xffff;	/* strip flags */
681
682	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500)
683		return -EINVAL;
684
685	netdev = alloc_netdev(sizeof(struct br2684_dev),
686			      ni.ifname[0] ? ni.ifname : "nas%d",
687			      NET_NAME_UNKNOWN,
688			      (payload == p_routed) ? br2684_setup_routed : br2684_setup);
689	if (!netdev)
690		return -ENOMEM;
691
692	brdev = BRPRIV(netdev);
693
694	pr_debug("registered netdev %s\n", netdev->name);
695	/* open, stop, do_ioctl ? */
696	err = register_netdev(netdev);
697	if (err < 0) {
698		pr_err("register_netdev failed\n");
699		free_netdev(netdev);
700		return err;
701	}
702
703	write_lock_irq(&devs_lock);
704
705	brdev->payload = payload;
706
707	if (list_empty(&br2684_devs)) {
708		/* 1st br2684 device */
709		brdev->number = 1;
710	} else
711		brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
712
713	list_add_tail(&brdev->br2684_devs, &br2684_devs);
714	write_unlock_irq(&devs_lock);
715	return 0;
716}
717
718/*
719 * This handles ioctls actually performed on our vcc - we must return
720 * -ENOIOCTLCMD for any unrecognized ioctl
721 */
722static int br2684_ioctl(struct socket *sock, unsigned int cmd,
723			unsigned long arg)
724{
725	struct atm_vcc *atmvcc = ATM_SD(sock);
726	void __user *argp = (void __user *)arg;
727	atm_backend_t b;
728
729	int err;
730	switch (cmd) {
731	case ATM_SETBACKEND:
732	case ATM_NEWBACKENDIF:
733		err = get_user(b, (atm_backend_t __user *) argp);
734		if (err)
735			return -EFAULT;
736		if (b != ATM_BACKEND_BR2684)
737			return -ENOIOCTLCMD;
738		if (!capable(CAP_NET_ADMIN))
739			return -EPERM;
740		if (cmd == ATM_SETBACKEND) {
741			if (sock->state != SS_CONNECTED)
742				return -EINVAL;
743			return br2684_regvcc(atmvcc, argp);
744		} else {
745			return br2684_create(argp);
746		}
747#ifdef CONFIG_ATM_BR2684_IPFILTER
748	case BR2684_SETFILT:
749		if (atmvcc->push != br2684_push)
750			return -ENOIOCTLCMD;
751		if (!capable(CAP_NET_ADMIN))
752			return -EPERM;
753		err = br2684_setfilt(atmvcc, argp);
754
755		return err;
756#endif /* CONFIG_ATM_BR2684_IPFILTER */
757	}
758	return -ENOIOCTLCMD;
759}
760
761static struct atm_ioctl br2684_ioctl_ops = {
762	.owner = THIS_MODULE,
763	.ioctl = br2684_ioctl,
764};
765
766#ifdef CONFIG_PROC_FS
767static void *br2684_seq_start(struct seq_file *seq, loff_t * pos)
768	__acquires(devs_lock)
769{
770	read_lock(&devs_lock);
771	return seq_list_start(&br2684_devs, *pos);
772}
773
774static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t * pos)
775{
776	return seq_list_next(v, &br2684_devs, pos);
777}
778
779static void br2684_seq_stop(struct seq_file *seq, void *v)
780	__releases(devs_lock)
781{
782	read_unlock(&devs_lock);
783}
784
785static int br2684_seq_show(struct seq_file *seq, void *v)
786{
787	const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
788						    br2684_devs);
789	const struct net_device *net_dev = brdev->net_dev;
790	const struct br2684_vcc *brvcc;
791
792	seq_printf(seq, "dev %.16s: num=%d, mac=%pM (%s)\n",
793		   net_dev->name,
794		   brdev->number,
795		   net_dev->dev_addr,
796		   brdev->mac_was_set ? "set" : "auto");
797
798	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
799		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
800			   ", failed copies %u/%u"
801			   "\n", brvcc->atmvcc->dev->number,
802			   brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
803			   (brvcc->encaps == e_llc) ? "LLC" : "VC",
804			   (brdev->payload == p_bridged) ? "bridged" : "routed",
805			   brvcc->copies_failed, brvcc->copies_needed);
806#ifdef CONFIG_ATM_BR2684_IPFILTER
 
 
807		if (brvcc->filter.netmask != 0)
808			seq_printf(seq, "    filter=%pI4/%pI4\n",
809				   &brvcc->filter.prefix,
810				   &brvcc->filter.netmask);
 
811#endif /* CONFIG_ATM_BR2684_IPFILTER */
812	}
813	return 0;
814}
815
816static const struct seq_operations br2684_seq_ops = {
817	.start = br2684_seq_start,
818	.next = br2684_seq_next,
819	.stop = br2684_seq_stop,
820	.show = br2684_seq_show,
821};
822
 
 
 
 
 
 
 
 
 
 
 
 
 
823extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
824#endif /* CONFIG_PROC_FS */
825
826static int __init br2684_init(void)
827{
828#ifdef CONFIG_PROC_FS
829	struct proc_dir_entry *p;
830	p = proc_create_seq("br2684", 0, atm_proc_root, &br2684_seq_ops);
831	if (p == NULL)
832		return -ENOMEM;
833#endif
834	register_atm_ioctl(&br2684_ioctl_ops);
835	register_atmdevice_notifier(&atm_dev_notifier);
836	return 0;
837}
838
839static void __exit br2684_exit(void)
840{
841	struct net_device *net_dev;
842	struct br2684_dev *brdev;
843	struct br2684_vcc *brvcc;
844	deregister_atm_ioctl(&br2684_ioctl_ops);
845
846#ifdef CONFIG_PROC_FS
847	remove_proc_entry("br2684", atm_proc_root);
848#endif
849
850
851	unregister_atmdevice_notifier(&atm_dev_notifier);
852
853	while (!list_empty(&br2684_devs)) {
854		net_dev = list_entry_brdev(br2684_devs.next);
855		brdev = BRPRIV(net_dev);
856		while (!list_empty(&brdev->brvccs)) {
857			brvcc = list_entry_brvcc(brdev->brvccs.next);
858			br2684_close_vcc(brvcc);
859		}
860
861		list_del(&brdev->br2684_devs);
862		unregister_netdev(net_dev);
863		free_netdev(net_dev);
864	}
865}
866
867module_init(br2684_init);
868module_exit(br2684_exit);
869
870MODULE_AUTHOR("Marcell GAL");
871MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
872MODULE_LICENSE("GPL");