blob: 58f4b1d7bf1fc303d5b962b9820aa423c943168b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * G8BPQ compatible "AX.25 via ethernet" driver release 004
3 *
4 * This code REQUIRES 2.0.0 or higher/ NET3.029
5 *
6 * This module:
7 * This module is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * This is a "pseudo" network driver to allow AX.25 over Ethernet
13 * using G8BPQ encapsulation. It has been extracted from the protocol
14 * implementation because
15 *
16 * - things got unreadable within the protocol stack
17 * - to cure the protocol stack from "feature-ism"
18 * - a protocol implementation shouldn't need to know on
19 * which hardware it is running
20 * - user-level programs like the AX.25 utilities shouldn't
21 * need to know about the hardware.
22 * - IP over ethernet encapsulated AX.25 was impossible
23 * - rxecho.c did not work
24 * - to have room for extensions
25 * - it just deserves to "live" as an own driver
26 *
27 * This driver can use any ethernet destination address, and can be
28 * limited to accept frames from one dedicated ethernet card only.
29 *
30 * Note that the driver sets up the BPQ devices automagically on
31 * startup or (if started before the "insmod" of an ethernet device)
32 * on "ifconfig up". It hopefully will remove the BPQ on "rmmod"ing
33 * the ethernet device (in fact: as soon as another ethernet or bpq
34 * device gets "ifconfig"ured).
35 *
36 * I have heard that several people are thinking of experiments
37 * with highspeed packet radio using existing ethernet cards.
38 * Well, this driver is prepared for this purpose, just add
39 * your tx key control and a txdelay / tailtime algorithm,
40 * probably some buffering, and /voila/...
41 *
42 * History
43 * BPQ 001 Joerg(DL1BKE) Extracted BPQ code from AX.25
44 * protocol stack and added my own
45 * yet existing patches
46 * BPQ 002 Joerg(DL1BKE) Scan network device list on
47 * startup.
48 * BPQ 003 Joerg(DL1BKE) Ethernet destination address
49 * and accepted source address
50 * can be configured by an ioctl()
51 * call.
52 * Fixed to match Linux networking
53 * changes - 2.1.15.
54 * BPQ 004 Joerg(DL1BKE) Fixed to not lock up on ifconfig.
55 */
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#include <linux/errno.h>
58#include <linux/types.h>
59#include <linux/socket.h>
60#include <linux/in.h>
61#include <linux/kernel.h>
62#include <linux/string.h>
63#include <linux/net.h>
64#include <net/ax25.h>
65#include <linux/inet.h>
66#include <linux/netdevice.h>
Joe Perches0795af52007-10-03 17:59:30 -070067#include <linux/etherdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#include <linux/if_arp.h>
69#include <linux/skbuff.h>
70#include <net/sock.h>
71#include <asm/system.h>
72#include <asm/uaccess.h>
73#include <linux/mm.h>
74#include <linux/interrupt.h>
75#include <linux/notifier.h>
76#include <linux/proc_fs.h>
77#include <linux/seq_file.h>
78#include <linux/stat.h>
79#include <linux/netfilter.h>
80#include <linux/module.h>
81#include <linux/init.h>
82#include <linux/rtnetlink.h>
83
84#include <net/ip.h>
85#include <net/arp.h>
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020086#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88#include <linux/bpqether.h>
89
90static char banner[] __initdata = KERN_INFO "AX.25: bpqether driver version 004\n";
91
Linus Torvalds1da177e2005-04-16 15:20:36 -070092static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
93
94static char bpq_eth_addr[6];
95
David S. Millerf2ccd8f2005-08-09 19:34:12 -070096static int bpq_rcv(struct sk_buff *, struct net_device *, struct packet_type *, struct net_device *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097static int bpq_device_event(struct notifier_block *, unsigned long, void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99static struct packet_type bpq_packet_type = {
100 .type = __constant_htons(ETH_P_BPQ),
101 .func = bpq_rcv,
102};
103
104static struct notifier_block bpq_dev_notifier = {
105 .notifier_call =bpq_device_event,
106};
107
108
109struct bpqdev {
110 struct list_head bpq_list; /* list of bpq devices chain */
111 struct net_device *ethdev; /* link to ethernet device */
112 struct net_device *axdev; /* bpq device (bpq#) */
113 struct net_device_stats stats; /* some statistics */
114 char dest_addr[6]; /* ether destination address */
115 char acpt_addr[6]; /* accept ether frames from this address only */
116};
117
118static LIST_HEAD(bpq_devices);
119
Ralf Baechle1eeb7e42006-07-10 11:24:46 -0700120/*
121 * bpqether network devices are paired with ethernet devices below them, so
122 * form a special "super class" of normal ethernet devices; split their locks
123 * off into a separate class since they always nest.
124 */
125static struct lock_class_key bpq_netdev_xmit_lock_key;
David S. Millercf508b12008-07-22 14:16:42 -0700126static struct lock_class_key bpq_netdev_addr_lock_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
David S. Millere8a04642008-07-17 00:34:19 -0700128static void bpq_set_lockdep_class_one(struct net_device *dev,
129 struct netdev_queue *txq,
130 void *_unused)
David S. Millerc773e842008-07-08 23:13:53 -0700131{
132 lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
133}
134
135static void bpq_set_lockdep_class(struct net_device *dev)
136{
David S. Millercf508b12008-07-22 14:16:42 -0700137 lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
David S. Millere8a04642008-07-17 00:34:19 -0700138 netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
David S. Millerc773e842008-07-08 23:13:53 -0700139}
140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141/* ------------------------------------------------------------------------ */
142
143
144/*
145 * Get the ethernet device for a BPQ device
146 */
147static inline struct net_device *bpq_get_ether_dev(struct net_device *dev)
148{
149 struct bpqdev *bpq = netdev_priv(dev);
150
151 return bpq ? bpq->ethdev : NULL;
152}
153
154/*
155 * Get the BPQ device for the ethernet device
156 */
157static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev)
158{
159 struct bpqdev *bpq;
160
Ralf Baechlebc0a7432005-10-17 12:42:32 +0100161 list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 if (bpq->ethdev == dev)
163 return bpq->axdev;
164 }
165 return NULL;
166}
167
168static inline int dev_is_ethdev(struct net_device *dev)
169{
170 return (
171 dev->type == ARPHRD_ETHER
172 && strncmp(dev->name, "dummy", 5)
173 );
174}
175
176/* ------------------------------------------------------------------------ */
177
178
179/*
180 * Receive an AX.25 frame via an ethernet interface.
181 */
David S. Millerf2ccd8f2005-08-09 19:34:12 -0700182static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183{
184 int len;
185 char * ptr;
186 struct ethhdr *eth;
187 struct bpqdev *bpq;
188
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900189 if (dev_net(dev) != &init_net)
Eric W. Biedermane730c152007-09-17 11:53:39 -0700190 goto drop;
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
193 return NET_RX_DROP;
194
195 if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
196 goto drop;
197
198 rcu_read_lock();
199 dev = bpq_get_ax25_dev(dev);
200
201 if (dev == NULL || !netif_running(dev))
202 goto drop_unlock;
203
204 /*
205 * if we want to accept frames from just one ethernet device
206 * we check the source address of the sender.
207 */
208
209 bpq = netdev_priv(dev);
210
211 eth = eth_hdr(skb);
212
213 if (!(bpq->acpt_addr[0] & 0x01) &&
214 memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN))
215 goto drop_unlock;
216
217 if (skb_cow(skb, sizeof(struct ethhdr)))
218 goto drop_unlock;
219
220 len = skb->data[0] + skb->data[1] * 256 - 5;
221
222 skb_pull(skb, 2); /* Remove the length bytes */
223 skb_trim(skb, len); /* Set the length of the data */
224
225 bpq->stats.rx_packets++;
226 bpq->stats.rx_bytes += len;
227
228 ptr = skb_push(skb, 1);
229 *ptr = 0;
230
Arnaldo Carvalho de Melo56cb5152005-04-24 18:53:06 -0700231 skb->protocol = ax25_type_trans(skb, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 netif_rx(skb);
233 dev->last_rx = jiffies;
234unlock:
235
236 rcu_read_unlock();
237
238 return 0;
239drop_unlock:
240 kfree_skb(skb);
241 goto unlock;
242
243drop:
244 kfree_skb(skb);
245 return 0;
246}
247
248/*
249 * Send an AX.25 frame via an ethernet interface
250 */
251static int bpq_xmit(struct sk_buff *skb, struct net_device *dev)
252{
253 struct sk_buff *newskb;
254 unsigned char *ptr;
255 struct bpqdev *bpq;
256 int size;
257
258 /*
259 * Just to be *really* sure not to send anything if the interface
260 * is down, the ethernet device may have gone.
261 */
262 if (!netif_running(dev)) {
263 kfree_skb(skb);
264 return -ENODEV;
265 }
266
267 skb_pull(skb, 1);
268 size = skb->len;
269
270 /*
271 * The AX.25 code leaves enough room for the ethernet header, but
272 * sendto() does not.
273 */
274 if (skb_headroom(skb) < AX25_BPQ_HEADER_LEN) { /* Ough! */
275 if ((newskb = skb_realloc_headroom(skb, AX25_BPQ_HEADER_LEN)) == NULL) {
276 printk(KERN_WARNING "bpqether: out of memory\n");
277 kfree_skb(skb);
278 return -ENOMEM;
279 }
280
281 if (skb->sk != NULL)
282 skb_set_owner_w(newskb, skb->sk);
283
284 kfree_skb(skb);
285 skb = newskb;
286 }
287
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 ptr = skb_push(skb, 2);
289
290 *ptr++ = (size + 5) % 256;
291 *ptr++ = (size + 5) / 256;
292
293 bpq = netdev_priv(dev);
294
295 if ((dev = bpq_get_ether_dev(dev)) == NULL) {
296 bpq->stats.tx_dropped++;
297 kfree_skb(skb);
298 return -ENODEV;
299 }
300
Arnaldo Carvalho de Melo56cb5152005-04-24 18:53:06 -0700301 skb->protocol = ax25_type_trans(skb, dev);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700302 skb_reset_network_header(skb);
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700303 dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 bpq->stats.tx_packets++;
305 bpq->stats.tx_bytes+=skb->len;
306
307 dev_queue_xmit(skb);
308 netif_wake_queue(dev);
309 return 0;
310}
311
312/*
313 * Statistics
314 */
315static struct net_device_stats *bpq_get_stats(struct net_device *dev)
316{
317 struct bpqdev *bpq = netdev_priv(dev);
318
319 return &bpq->stats;
320}
321
322/*
323 * Set AX.25 callsign
324 */
325static int bpq_set_mac_address(struct net_device *dev, void *addr)
326{
327 struct sockaddr *sa = (struct sockaddr *)addr;
328
329 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
330
331 return 0;
332}
333
334/* Ioctl commands
335 *
336 * SIOCSBPQETHOPT reserved for enhancements
337 * SIOCSBPQETHADDR set the destination and accepted
338 * source ethernet address (broadcast
339 * or multicast: accept all)
340 */
341static int bpq_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
342{
343 struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
344 struct bpqdev *bpq = netdev_priv(dev);
345 struct bpq_req req;
346
347 if (!capable(CAP_NET_ADMIN))
348 return -EPERM;
349
350 switch (cmd) {
351 case SIOCSBPQETHOPT:
352 if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
353 return -EFAULT;
354 switch (req.cmd) {
355 case SIOCGBPQETHPARAM:
356 case SIOCSBPQETHPARAM:
357 default:
358 return -EINVAL;
359 }
360
361 break;
362
363 case SIOCSBPQETHADDR:
364 if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
365 return -EFAULT;
366 if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
367 return -EFAULT;
368 break;
369
370 default:
371 return -EINVAL;
372 }
373
374 return 0;
375}
376
377/*
378 * open/close a device
379 */
380static int bpq_open(struct net_device *dev)
381{
382 netif_start_queue(dev);
383 return 0;
384}
385
386static int bpq_close(struct net_device *dev)
387{
388 netif_stop_queue(dev);
389 return 0;
390}
391
392
393/* ------------------------------------------------------------------------ */
394
395
396/*
397 * Proc filesystem
398 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
400{
401 int i = 1;
402 struct bpqdev *bpqdev;
403
404 rcu_read_lock();
405
406 if (*pos == 0)
407 return SEQ_START_TOKEN;
408
Ralf Baechlebc0a7432005-10-17 12:42:32 +0100409 list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 if (i == *pos)
411 return bpqdev;
412 }
413 return NULL;
414}
415
416static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
417{
418 struct list_head *p;
419
420 ++*pos;
421
422 if (v == SEQ_START_TOKEN)
Paul E. McKenneyb34bd062007-07-31 00:38:48 -0700423 p = rcu_dereference(bpq_devices.next);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 else
Paul E. McKenneyb34bd062007-07-31 00:38:48 -0700425 p = rcu_dereference(((struct bpqdev *)v)->bpq_list.next);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 return (p == &bpq_devices) ? NULL
Paul E. McKenneyb34bd062007-07-31 00:38:48 -0700428 : list_entry(p, struct bpqdev, bpq_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429}
430
431static void bpq_seq_stop(struct seq_file *seq, void *v)
432{
433 rcu_read_unlock();
434}
435
436
437static int bpq_seq_show(struct seq_file *seq, void *v)
438{
439 if (v == SEQ_START_TOKEN)
440 seq_puts(seq,
441 "dev ether destination accept from\n");
442 else {
443 const struct bpqdev *bpqdev = v;
Joe Perches0795af52007-10-03 17:59:30 -0700444 DECLARE_MAC_BUF(mac);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
446 seq_printf(seq, "%-5s %-10s %s ",
447 bpqdev->axdev->name, bpqdev->ethdev->name,
Joe Perches0795af52007-10-03 17:59:30 -0700448 print_mac(mac, bpqdev->dest_addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
Joe Perches0795af52007-10-03 17:59:30 -0700450 if (is_multicast_ether_addr(bpqdev->acpt_addr))
451 seq_printf(seq, "*\n");
452 else
453 seq_printf(seq, "%s\n", print_mac(mac, bpqdev->acpt_addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
455 }
456 return 0;
457}
458
459static struct seq_operations bpq_seqops = {
460 .start = bpq_seq_start,
461 .next = bpq_seq_next,
462 .stop = bpq_seq_stop,
463 .show = bpq_seq_show,
464};
465
466static int bpq_info_open(struct inode *inode, struct file *file)
467{
468 return seq_open(file, &bpq_seqops);
469}
470
Arjan van de Vend54b1fd2007-02-12 00:55:34 -0800471static const struct file_operations bpq_info_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 .owner = THIS_MODULE,
473 .open = bpq_info_open,
474 .read = seq_read,
475 .llseek = seq_lseek,
476 .release = seq_release,
477};
478
479
480/* ------------------------------------------------------------------------ */
481
482
483static void bpq_setup(struct net_device *dev)
484{
485
486 dev->hard_start_xmit = bpq_xmit;
487 dev->open = bpq_open;
488 dev->stop = bpq_close;
489 dev->set_mac_address = bpq_set_mac_address;
490 dev->get_stats = bpq_get_stats;
491 dev->do_ioctl = bpq_ioctl;
492 dev->destructor = free_netdev;
493
Ralf Baechle15b1c0e2006-12-07 15:47:08 -0800494 memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
495 memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
497 dev->flags = 0;
498
499#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700500 dev->header_ops = &ax25_header_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501#endif
502
503 dev->type = ARPHRD_AX25;
504 dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
505 dev->mtu = AX25_DEF_PACLEN;
506 dev->addr_len = AX25_ADDR_LEN;
507
508}
509
510/*
511 * Setup a new device.
512 */
513static int bpq_new_device(struct net_device *edev)
514{
515 int err;
516 struct net_device *ndev;
517 struct bpqdev *bpq;
518
519 ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d",
520 bpq_setup);
521 if (!ndev)
522 return -ENOMEM;
523
524
525 bpq = netdev_priv(ndev);
526 dev_hold(edev);
527 bpq->ethdev = edev;
528 bpq->axdev = ndev;
529
530 memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
531 memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));
532
533 err = dev_alloc_name(ndev, ndev->name);
534 if (err < 0)
535 goto error;
536
537 err = register_netdevice(ndev);
538 if (err)
539 goto error;
David S. Millerc773e842008-07-08 23:13:53 -0700540 bpq_set_lockdep_class(ndev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541
542 /* List protected by RTNL */
543 list_add_rcu(&bpq->bpq_list, &bpq_devices);
544 return 0;
545
546 error:
547 dev_put(edev);
548 free_netdev(ndev);
549 return err;
550
551}
552
553static void bpq_free_device(struct net_device *ndev)
554{
555 struct bpqdev *bpq = netdev_priv(ndev);
556
557 dev_put(bpq->ethdev);
558 list_del_rcu(&bpq->bpq_list);
559
560 unregister_netdevice(ndev);
561}
562
563/*
564 * Handle device status changes.
565 */
566static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr)
567{
568 struct net_device *dev = (struct net_device *)ptr;
569
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900570 if (dev_net(dev) != &init_net)
Eric W. Biedermane9dc8652007-09-12 13:02:17 +0200571 return NOTIFY_DONE;
572
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 if (!dev_is_ethdev(dev))
574 return NOTIFY_DONE;
575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 switch (event) {
577 case NETDEV_UP: /* new ethernet device -> new BPQ interface */
578 if (bpq_get_ax25_dev(dev) == NULL)
579 bpq_new_device(dev);
580 break;
581
582 case NETDEV_DOWN: /* ethernet device closed -> close BPQ interface */
583 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
584 dev_close(dev);
585 break;
586
587 case NETDEV_UNREGISTER: /* ethernet device removed -> free BPQ interface */
588 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
589 bpq_free_device(dev);
590 break;
591 default:
592 break;
593 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
595 return NOTIFY_DONE;
596}
597
598
599/* ------------------------------------------------------------------------ */
600
601/*
602 * Initialize driver. To be called from af_ax25 if not compiled as a
603 * module
604 */
605static int __init bpq_init_driver(void)
606{
607#ifdef CONFIG_PROC_FS
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200608 if (!proc_net_fops_create(&init_net, "bpqether", S_IRUGO, &bpq_info_fops)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 printk(KERN_ERR
610 "bpq: cannot create /proc/net/bpqether entry.\n");
611 return -ENOENT;
612 }
613#endif /* CONFIG_PROC_FS */
614
615 dev_add_pack(&bpq_packet_type);
616
617 register_netdevice_notifier(&bpq_dev_notifier);
618
619 printk(banner);
620
621 return 0;
622}
623
624static void __exit bpq_cleanup_driver(void)
625{
626 struct bpqdev *bpq;
627
628 dev_remove_pack(&bpq_packet_type);
629
630 unregister_netdevice_notifier(&bpq_dev_notifier);
631
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200632 proc_net_remove(&init_net, "bpqether");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
634 rtnl_lock();
635 while (!list_empty(&bpq_devices)) {
636 bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
637 bpq_free_device(bpq->axdev);
638 }
639 rtnl_unlock();
640}
641
642MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
643MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
644MODULE_LICENSE("GPL");
645module_init(bpq_init_driver);
646module_exit(bpq_cleanup_driver);