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52#include <linux/errno.h>
53#include <linux/types.h>
54#include <linux/socket.h>
55#include <linux/in.h>
56#include <linux/kernel.h>
57#include <linux/string.h>
58#include <linux/net.h>
59#include <linux/slab.h>
60#include <net/ax25.h>
61#include <linux/inet.h>
62#include <linux/netdevice.h>
63#include <linux/etherdevice.h>
64#include <linux/if_arp.h>
65#include <linux/skbuff.h>
66#include <net/sock.h>
67#include <linux/uaccess.h>
68#include <linux/mm.h>
69#include <linux/interrupt.h>
70#include <linux/notifier.h>
71#include <linux/proc_fs.h>
72#include <linux/seq_file.h>
73#include <linux/stat.h>
74#include <linux/module.h>
75#include <linux/init.h>
76#include <linux/rtnetlink.h>
77
78#include <net/ip.h>
79#include <net/arp.h>
80#include <net/net_namespace.h>
81
82#include <linux/bpqether.h>
83
84static const char banner[] __initconst = KERN_INFO \
85 "AX.25: bpqether driver version 004\n";
86
87static int bpq_rcv(struct sk_buff *, struct net_device *, struct packet_type *, struct net_device *);
88static int bpq_device_event(struct notifier_block *, unsigned long, void *);
89
90static struct packet_type bpq_packet_type __read_mostly = {
91 .type = cpu_to_be16(ETH_P_BPQ),
92 .func = bpq_rcv,
93};
94
95static struct notifier_block bpq_dev_notifier = {
96 .notifier_call = bpq_device_event,
97};
98
99
100struct bpqdev {
101 struct list_head bpq_list;
102 struct net_device *ethdev;
103 struct net_device *axdev;
104 char dest_addr[6];
105 char acpt_addr[6];
106};
107
108static LIST_HEAD(bpq_devices);
109
110
111
112
113
114
115static struct lock_class_key bpq_netdev_xmit_lock_key;
116static struct lock_class_key bpq_netdev_addr_lock_key;
117
118static void bpq_set_lockdep_class_one(struct net_device *dev,
119 struct netdev_queue *txq,
120 void *_unused)
121{
122 lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
123}
124
125static void bpq_set_lockdep_class(struct net_device *dev)
126{
127 lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
128 netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
129}
130
131
132
133
134
135
136
137static inline struct net_device *bpq_get_ether_dev(struct net_device *dev)
138{
139 struct bpqdev *bpq = netdev_priv(dev);
140
141 return bpq ? bpq->ethdev : NULL;
142}
143
144
145
146
147static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev)
148{
149 struct bpqdev *bpq;
150
151 list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list,
152 lockdep_rtnl_is_held()) {
153 if (bpq->ethdev == dev)
154 return bpq->axdev;
155 }
156 return NULL;
157}
158
159static inline int dev_is_ethdev(struct net_device *dev)
160{
161 return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
162}
163
164
165
166
167
168
169
170static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
171{
172 int len;
173 char * ptr;
174 struct ethhdr *eth;
175 struct bpqdev *bpq;
176
177 if (!net_eq(dev_net(dev), &init_net))
178 goto drop;
179
180 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
181 return NET_RX_DROP;
182
183 if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
184 goto drop;
185
186 rcu_read_lock();
187 dev = bpq_get_ax25_dev(dev);
188
189 if (dev == NULL || !netif_running(dev))
190 goto drop_unlock;
191
192
193
194
195
196
197 bpq = netdev_priv(dev);
198
199 eth = eth_hdr(skb);
200
201 if (!(bpq->acpt_addr[0] & 0x01) &&
202 !ether_addr_equal(eth->h_source, bpq->acpt_addr))
203 goto drop_unlock;
204
205 if (skb_cow(skb, sizeof(struct ethhdr)))
206 goto drop_unlock;
207
208 len = skb->data[0] + skb->data[1] * 256 - 5;
209
210 skb_pull(skb, 2);
211 skb_trim(skb, len);
212
213 dev->stats.rx_packets++;
214 dev->stats.rx_bytes += len;
215
216 ptr = skb_push(skb, 1);
217 *ptr = 0;
218
219 skb->protocol = ax25_type_trans(skb, dev);
220 netif_rx(skb);
221unlock:
222
223 rcu_read_unlock();
224
225 return 0;
226drop_unlock:
227 kfree_skb(skb);
228 goto unlock;
229
230drop:
231 kfree_skb(skb);
232 return 0;
233}
234
235
236
237
238static netdev_tx_t bpq_xmit(struct sk_buff *skb, struct net_device *dev)
239{
240 unsigned char *ptr;
241 struct bpqdev *bpq;
242 struct net_device *orig_dev;
243 int size;
244
245 if (skb->protocol == htons(ETH_P_IP))
246 return ax25_ip_xmit(skb);
247
248
249
250
251
252 if (!netif_running(dev)) {
253 kfree_skb(skb);
254 return NETDEV_TX_OK;
255 }
256
257 skb_pull(skb, 1);
258 size = skb->len;
259
260
261
262
263
264
265 if (skb_cow(skb, AX25_BPQ_HEADER_LEN)) {
266 if (net_ratelimit())
267 pr_err("bpqether: out of memory\n");
268 kfree_skb(skb);
269
270 return NETDEV_TX_OK;
271 }
272
273 ptr = skb_push(skb, 2);
274
275 *ptr++ = (size + 5) % 256;
276 *ptr++ = (size + 5) / 256;
277
278 bpq = netdev_priv(dev);
279
280 orig_dev = dev;
281 if ((dev = bpq_get_ether_dev(dev)) == NULL) {
282 orig_dev->stats.tx_dropped++;
283 kfree_skb(skb);
284 return NETDEV_TX_OK;
285 }
286
287 skb->protocol = ax25_type_trans(skb, dev);
288 skb_reset_network_header(skb);
289 dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
290 dev->stats.tx_packets++;
291 dev->stats.tx_bytes+=skb->len;
292
293 dev_queue_xmit(skb);
294 netif_wake_queue(dev);
295 return NETDEV_TX_OK;
296}
297
298
299
300
301static int bpq_set_mac_address(struct net_device *dev, void *addr)
302{
303 struct sockaddr *sa = (struct sockaddr *)addr;
304
305 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
306
307 return 0;
308}
309
310
311
312
313
314
315
316
317static int bpq_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
318 void __user *data, int cmd)
319{
320 struct bpq_ethaddr __user *ethaddr = data;
321 struct bpqdev *bpq = netdev_priv(dev);
322 struct bpq_req req;
323
324 if (!capable(CAP_NET_ADMIN))
325 return -EPERM;
326
327 switch (cmd) {
328 case SIOCSBPQETHOPT:
329 if (copy_from_user(&req, data, sizeof(struct bpq_req)))
330 return -EFAULT;
331 switch (req.cmd) {
332 case SIOCGBPQETHPARAM:
333 case SIOCSBPQETHPARAM:
334 default:
335 return -EINVAL;
336 }
337
338 break;
339
340 case SIOCSBPQETHADDR:
341 if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
342 return -EFAULT;
343 if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
344 return -EFAULT;
345 break;
346
347 default:
348 return -EINVAL;
349 }
350
351 return 0;
352}
353
354
355
356
357static int bpq_open(struct net_device *dev)
358{
359 netif_start_queue(dev);
360 return 0;
361}
362
363static int bpq_close(struct net_device *dev)
364{
365 netif_stop_queue(dev);
366 return 0;
367}
368
369
370
371
372#ifdef CONFIG_PROC_FS
373
374
375
376static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
377 __acquires(RCU)
378{
379 int i = 1;
380 struct bpqdev *bpqdev;
381
382 rcu_read_lock();
383
384 if (*pos == 0)
385 return SEQ_START_TOKEN;
386
387 list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
388 if (i == *pos)
389 return bpqdev;
390 }
391 return NULL;
392}
393
394static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
395{
396 struct list_head *p;
397 struct bpqdev *bpqdev = v;
398
399 ++*pos;
400
401 if (v == SEQ_START_TOKEN)
402 p = rcu_dereference(list_next_rcu(&bpq_devices));
403 else
404 p = rcu_dereference(list_next_rcu(&bpqdev->bpq_list));
405
406 return (p == &bpq_devices) ? NULL
407 : list_entry(p, struct bpqdev, bpq_list);
408}
409
410static void bpq_seq_stop(struct seq_file *seq, void *v)
411 __releases(RCU)
412{
413 rcu_read_unlock();
414}
415
416
417static int bpq_seq_show(struct seq_file *seq, void *v)
418{
419 if (v == SEQ_START_TOKEN)
420 seq_puts(seq,
421 "dev ether destination accept from\n");
422 else {
423 const struct bpqdev *bpqdev = v;
424
425 seq_printf(seq, "%-5s %-10s %pM ",
426 bpqdev->axdev->name, bpqdev->ethdev->name,
427 bpqdev->dest_addr);
428
429 if (is_multicast_ether_addr(bpqdev->acpt_addr))
430 seq_printf(seq, "*\n");
431 else
432 seq_printf(seq, "%pM\n", bpqdev->acpt_addr);
433
434 }
435 return 0;
436}
437
438static const struct seq_operations bpq_seqops = {
439 .start = bpq_seq_start,
440 .next = bpq_seq_next,
441 .stop = bpq_seq_stop,
442 .show = bpq_seq_show,
443};
444#endif
445
446
447static const struct net_device_ops bpq_netdev_ops = {
448 .ndo_open = bpq_open,
449 .ndo_stop = bpq_close,
450 .ndo_start_xmit = bpq_xmit,
451 .ndo_set_mac_address = bpq_set_mac_address,
452 .ndo_siocdevprivate = bpq_siocdevprivate,
453};
454
455static void bpq_setup(struct net_device *dev)
456{
457 dev->netdev_ops = &bpq_netdev_ops;
458 dev->needs_free_netdev = true;
459
460 memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
461 memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
462
463 dev->flags = 0;
464 dev->features = NETIF_F_LLTX;
465
466#if IS_ENABLED(CONFIG_AX25)
467 dev->header_ops = &ax25_header_ops;
468#endif
469
470 dev->type = ARPHRD_AX25;
471 dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
472 dev->mtu = AX25_DEF_PACLEN;
473 dev->addr_len = AX25_ADDR_LEN;
474
475}
476
477
478
479
480static int bpq_new_device(struct net_device *edev)
481{
482 int err;
483 struct net_device *ndev;
484 struct bpqdev *bpq;
485
486 ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d", NET_NAME_UNKNOWN,
487 bpq_setup);
488 if (!ndev)
489 return -ENOMEM;
490
491
492 bpq = netdev_priv(ndev);
493 dev_hold(edev);
494 bpq->ethdev = edev;
495 bpq->axdev = ndev;
496
497 eth_broadcast_addr(bpq->dest_addr);
498 eth_broadcast_addr(bpq->acpt_addr);
499
500 err = register_netdevice(ndev);
501 if (err)
502 goto error;
503 bpq_set_lockdep_class(ndev);
504
505
506 list_add_rcu(&bpq->bpq_list, &bpq_devices);
507 return 0;
508
509 error:
510 dev_put(edev);
511 free_netdev(ndev);
512 return err;
513
514}
515
516static void bpq_free_device(struct net_device *ndev)
517{
518 struct bpqdev *bpq = netdev_priv(ndev);
519
520 dev_put(bpq->ethdev);
521 list_del_rcu(&bpq->bpq_list);
522
523 unregister_netdevice(ndev);
524}
525
526
527
528
529static int bpq_device_event(struct notifier_block *this,
530 unsigned long event, void *ptr)
531{
532 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
533
534 if (!net_eq(dev_net(dev), &init_net))
535 return NOTIFY_DONE;
536
537 if (!dev_is_ethdev(dev))
538 return NOTIFY_DONE;
539
540 switch (event) {
541 case NETDEV_UP:
542 if (bpq_get_ax25_dev(dev) == NULL)
543 bpq_new_device(dev);
544 break;
545
546 case NETDEV_DOWN:
547 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
548 dev_close(dev);
549 break;
550
551 case NETDEV_UNREGISTER:
552 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
553 bpq_free_device(dev);
554 break;
555 default:
556 break;
557 }
558
559 return NOTIFY_DONE;
560}
561
562
563
564
565
566
567
568
569static int __init bpq_init_driver(void)
570{
571#ifdef CONFIG_PROC_FS
572 if (!proc_create_seq("bpqether", 0444, init_net.proc_net, &bpq_seqops)) {
573 printk(KERN_ERR
574 "bpq: cannot create /proc/net/bpqether entry.\n");
575 return -ENOENT;
576 }
577#endif
578
579 dev_add_pack(&bpq_packet_type);
580
581 register_netdevice_notifier(&bpq_dev_notifier);
582
583 printk(banner);
584
585 return 0;
586}
587
588static void __exit bpq_cleanup_driver(void)
589{
590 struct bpqdev *bpq;
591
592 dev_remove_pack(&bpq_packet_type);
593
594 unregister_netdevice_notifier(&bpq_dev_notifier);
595
596 remove_proc_entry("bpqether", init_net.proc_net);
597
598 rtnl_lock();
599 while (!list_empty(&bpq_devices)) {
600 bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
601 bpq_free_device(bpq->axdev);
602 }
603 rtnl_unlock();
604}
605
606MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
607MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
608MODULE_LICENSE("GPL");
609module_init(bpq_init_driver);
610module_exit(bpq_cleanup_driver);
611