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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");
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");