2 * G8BPQ compatible "AX.25 via ethernet" driver release 004
4 * This code REQUIRES 2.0.0 or higher/ NET3.029
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.
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
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
27 * This driver can use any ethernet destination address, and can be
28 * limited to accept frames from one dedicated ethernet card only.
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).
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/...
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
48 * BPQ 003 Joerg(DL1BKE) Ethernet destination address
49 * and accepted source address
50 * can be configured by an ioctl()
52 * Fixed to match Linux networking
54 * BPQ 004 Joerg(DL1BKE) Fixed to not lock up on ifconfig.
57 #include <linux/errno.h>
58 #include <linux/types.h>
59 #include <linux/socket.h>
61 #include <linux/kernel.h>
62 #include <linux/string.h>
63 #include <linux/net.h>
65 #include <linux/inet.h>
66 #include <linux/netdevice.h>
67 #include <linux/if_ether.h>
68 #include <linux/if_arp.h>
69 #include <linux/skbuff.h>
71 #include <asm/system.h>
72 #include <asm/uaccess.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>
86 #include <net/net_namespace.h>
88 #include <linux/bpqether.h>
90 static char banner
[] __initdata
= KERN_INFO
"AX.25: bpqether driver version 004\n";
92 static char bcast_addr
[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
94 static char bpq_eth_addr
[6];
96 static int bpq_rcv(struct sk_buff
*, struct net_device
*, struct packet_type
*, struct net_device
*);
97 static int bpq_device_event(struct notifier_block
*, unsigned long, void *);
98 static const char *bpq_print_ethaddr(const unsigned char *);
100 static struct packet_type bpq_packet_type
= {
101 .type
= __constant_htons(ETH_P_BPQ
),
105 static struct notifier_block bpq_dev_notifier
= {
106 .notifier_call
=bpq_device_event
,
111 struct list_head bpq_list
; /* list of bpq devices chain */
112 struct net_device
*ethdev
; /* link to ethernet device */
113 struct net_device
*axdev
; /* bpq device (bpq#) */
114 struct net_device_stats stats
; /* some statistics */
115 char dest_addr
[6]; /* ether destination address */
116 char acpt_addr
[6]; /* accept ether frames from this address only */
119 static LIST_HEAD(bpq_devices
);
122 * bpqether network devices are paired with ethernet devices below them, so
123 * form a special "super class" of normal ethernet devices; split their locks
124 * off into a separate class since they always nest.
126 static struct lock_class_key bpq_netdev_xmit_lock_key
;
128 /* ------------------------------------------------------------------------ */
132 * Get the ethernet device for a BPQ device
134 static inline struct net_device
*bpq_get_ether_dev(struct net_device
*dev
)
136 struct bpqdev
*bpq
= netdev_priv(dev
);
138 return bpq
? bpq
->ethdev
: NULL
;
142 * Get the BPQ device for the ethernet device
144 static inline struct net_device
*bpq_get_ax25_dev(struct net_device
*dev
)
148 list_for_each_entry_rcu(bpq
, &bpq_devices
, bpq_list
) {
149 if (bpq
->ethdev
== dev
)
155 static inline int dev_is_ethdev(struct net_device
*dev
)
158 dev
->type
== ARPHRD_ETHER
159 && strncmp(dev
->name
, "dummy", 5)
163 /* ------------------------------------------------------------------------ */
167 * Receive an AX.25 frame via an ethernet interface.
169 static int bpq_rcv(struct sk_buff
*skb
, struct net_device
*dev
, struct packet_type
*ptype
, struct net_device
*orig_dev
)
176 if (dev
->nd_net
!= &init_net
)
179 if ((skb
= skb_share_check(skb
, GFP_ATOMIC
)) == NULL
)
182 if (!pskb_may_pull(skb
, sizeof(struct ethhdr
)))
186 dev
= bpq_get_ax25_dev(dev
);
188 if (dev
== NULL
|| !netif_running(dev
))
192 * if we want to accept frames from just one ethernet device
193 * we check the source address of the sender.
196 bpq
= netdev_priv(dev
);
200 if (!(bpq
->acpt_addr
[0] & 0x01) &&
201 memcmp(eth
->h_source
, bpq
->acpt_addr
, ETH_ALEN
))
204 if (skb_cow(skb
, sizeof(struct ethhdr
)))
207 len
= skb
->data
[0] + skb
->data
[1] * 256 - 5;
209 skb_pull(skb
, 2); /* Remove the length bytes */
210 skb_trim(skb
, len
); /* Set the length of the data */
212 bpq
->stats
.rx_packets
++;
213 bpq
->stats
.rx_bytes
+= len
;
215 ptr
= skb_push(skb
, 1);
218 skb
->protocol
= ax25_type_trans(skb
, dev
);
220 dev
->last_rx
= jiffies
;
236 * Send an AX.25 frame via an ethernet interface
238 static int bpq_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
240 struct sk_buff
*newskb
;
246 * Just to be *really* sure not to send anything if the interface
247 * is down, the ethernet device may have gone.
249 if (!netif_running(dev
)) {
258 * The AX.25 code leaves enough room for the ethernet header, but
261 if (skb_headroom(skb
) < AX25_BPQ_HEADER_LEN
) { /* Ough! */
262 if ((newskb
= skb_realloc_headroom(skb
, AX25_BPQ_HEADER_LEN
)) == NULL
) {
263 printk(KERN_WARNING
"bpqether: out of memory\n");
269 skb_set_owner_w(newskb
, skb
->sk
);
275 ptr
= skb_push(skb
, 2);
277 *ptr
++ = (size
+ 5) % 256;
278 *ptr
++ = (size
+ 5) / 256;
280 bpq
= netdev_priv(dev
);
282 if ((dev
= bpq_get_ether_dev(dev
)) == NULL
) {
283 bpq
->stats
.tx_dropped
++;
288 skb
->protocol
= ax25_type_trans(skb
, dev
);
289 skb_reset_network_header(skb
);
290 dev
->hard_header(skb
, dev
, ETH_P_BPQ
, bpq
->dest_addr
, NULL
, 0);
291 bpq
->stats
.tx_packets
++;
292 bpq
->stats
.tx_bytes
+=skb
->len
;
295 netif_wake_queue(dev
);
302 static struct net_device_stats
*bpq_get_stats(struct net_device
*dev
)
304 struct bpqdev
*bpq
= netdev_priv(dev
);
312 static int bpq_set_mac_address(struct net_device
*dev
, void *addr
)
314 struct sockaddr
*sa
= (struct sockaddr
*)addr
;
316 memcpy(dev
->dev_addr
, sa
->sa_data
, dev
->addr_len
);
323 * SIOCSBPQETHOPT reserved for enhancements
324 * SIOCSBPQETHADDR set the destination and accepted
325 * source ethernet address (broadcast
326 * or multicast: accept all)
328 static int bpq_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
330 struct bpq_ethaddr __user
*ethaddr
= ifr
->ifr_data
;
331 struct bpqdev
*bpq
= netdev_priv(dev
);
334 if (!capable(CAP_NET_ADMIN
))
339 if (copy_from_user(&req
, ifr
->ifr_data
, sizeof(struct bpq_req
)))
342 case SIOCGBPQETHPARAM
:
343 case SIOCSBPQETHPARAM
:
350 case SIOCSBPQETHADDR
:
351 if (copy_from_user(bpq
->dest_addr
, ethaddr
->destination
, ETH_ALEN
))
353 if (copy_from_user(bpq
->acpt_addr
, ethaddr
->accept
, ETH_ALEN
))
365 * open/close a device
367 static int bpq_open(struct net_device
*dev
)
369 netif_start_queue(dev
);
373 static int bpq_close(struct net_device
*dev
)
375 netif_stop_queue(dev
);
380 /* ------------------------------------------------------------------------ */
386 static const char * bpq_print_ethaddr(const unsigned char *e
)
390 sprintf(buf
, "%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X",
391 e
[0], e
[1], e
[2], e
[3], e
[4], e
[5]);
396 static void *bpq_seq_start(struct seq_file
*seq
, loff_t
*pos
)
399 struct bpqdev
*bpqdev
;
404 return SEQ_START_TOKEN
;
406 list_for_each_entry_rcu(bpqdev
, &bpq_devices
, bpq_list
) {
413 static void *bpq_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
419 if (v
== SEQ_START_TOKEN
)
420 p
= rcu_dereference(bpq_devices
.next
);
422 p
= rcu_dereference(((struct bpqdev
*)v
)->bpq_list
.next
);
424 return (p
== &bpq_devices
) ? NULL
425 : list_entry(p
, struct bpqdev
, bpq_list
);
428 static void bpq_seq_stop(struct seq_file
*seq
, void *v
)
434 static int bpq_seq_show(struct seq_file
*seq
, void *v
)
436 if (v
== SEQ_START_TOKEN
)
438 "dev ether destination accept from\n");
440 const struct bpqdev
*bpqdev
= v
;
442 seq_printf(seq
, "%-5s %-10s %s ",
443 bpqdev
->axdev
->name
, bpqdev
->ethdev
->name
,
444 bpq_print_ethaddr(bpqdev
->dest_addr
));
446 seq_printf(seq
, "%s\n",
447 (bpqdev
->acpt_addr
[0] & 0x01) ? "*"
448 : bpq_print_ethaddr(bpqdev
->acpt_addr
));
454 static struct seq_operations bpq_seqops
= {
455 .start
= bpq_seq_start
,
456 .next
= bpq_seq_next
,
457 .stop
= bpq_seq_stop
,
458 .show
= bpq_seq_show
,
461 static int bpq_info_open(struct inode
*inode
, struct file
*file
)
463 return seq_open(file
, &bpq_seqops
);
466 static const struct file_operations bpq_info_fops
= {
467 .owner
= THIS_MODULE
,
468 .open
= bpq_info_open
,
471 .release
= seq_release
,
475 /* ------------------------------------------------------------------------ */
478 static void bpq_setup(struct net_device
*dev
)
481 dev
->hard_start_xmit
= bpq_xmit
;
482 dev
->open
= bpq_open
;
483 dev
->stop
= bpq_close
;
484 dev
->set_mac_address
= bpq_set_mac_address
;
485 dev
->get_stats
= bpq_get_stats
;
486 dev
->do_ioctl
= bpq_ioctl
;
487 dev
->destructor
= free_netdev
;
489 memcpy(dev
->broadcast
, &ax25_bcast
, AX25_ADDR_LEN
);
490 memcpy(dev
->dev_addr
, &ax25_defaddr
, AX25_ADDR_LEN
);
494 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
495 dev
->hard_header
= ax25_hard_header
;
496 dev
->rebuild_header
= ax25_rebuild_header
;
499 dev
->type
= ARPHRD_AX25
;
500 dev
->hard_header_len
= AX25_MAX_HEADER_LEN
+ AX25_BPQ_HEADER_LEN
;
501 dev
->mtu
= AX25_DEF_PACLEN
;
502 dev
->addr_len
= AX25_ADDR_LEN
;
507 * Setup a new device.
509 static int bpq_new_device(struct net_device
*edev
)
512 struct net_device
*ndev
;
515 ndev
= alloc_netdev(sizeof(struct bpqdev
), "bpq%d",
521 bpq
= netdev_priv(ndev
);
526 memcpy(bpq
->dest_addr
, bcast_addr
, sizeof(bpq_eth_addr
));
527 memcpy(bpq
->acpt_addr
, bcast_addr
, sizeof(bpq_eth_addr
));
529 err
= dev_alloc_name(ndev
, ndev
->name
);
533 err
= register_netdevice(ndev
);
536 lockdep_set_class(&ndev
->_xmit_lock
, &bpq_netdev_xmit_lock_key
);
538 /* List protected by RTNL */
539 list_add_rcu(&bpq
->bpq_list
, &bpq_devices
);
549 static void bpq_free_device(struct net_device
*ndev
)
551 struct bpqdev
*bpq
= netdev_priv(ndev
);
553 dev_put(bpq
->ethdev
);
554 list_del_rcu(&bpq
->bpq_list
);
556 unregister_netdevice(ndev
);
560 * Handle device status changes.
562 static int bpq_device_event(struct notifier_block
*this,unsigned long event
, void *ptr
)
564 struct net_device
*dev
= (struct net_device
*)ptr
;
566 if (dev
->nd_net
!= &init_net
)
569 if (!dev_is_ethdev(dev
))
573 case NETDEV_UP
: /* new ethernet device -> new BPQ interface */
574 if (bpq_get_ax25_dev(dev
) == NULL
)
578 case NETDEV_DOWN
: /* ethernet device closed -> close BPQ interface */
579 if ((dev
= bpq_get_ax25_dev(dev
)) != NULL
)
583 case NETDEV_UNREGISTER
: /* ethernet device removed -> free BPQ interface */
584 if ((dev
= bpq_get_ax25_dev(dev
)) != NULL
)
585 bpq_free_device(dev
);
595 /* ------------------------------------------------------------------------ */
598 * Initialize driver. To be called from af_ax25 if not compiled as a
601 static int __init
bpq_init_driver(void)
603 #ifdef CONFIG_PROC_FS
604 if (!proc_net_fops_create(&init_net
, "bpqether", S_IRUGO
, &bpq_info_fops
)) {
606 "bpq: cannot create /proc/net/bpqether entry.\n");
609 #endif /* CONFIG_PROC_FS */
611 dev_add_pack(&bpq_packet_type
);
613 register_netdevice_notifier(&bpq_dev_notifier
);
620 static void __exit
bpq_cleanup_driver(void)
624 dev_remove_pack(&bpq_packet_type
);
626 unregister_netdevice_notifier(&bpq_dev_notifier
);
628 proc_net_remove(&init_net
, "bpqether");
631 while (!list_empty(&bpq_devices
)) {
632 bpq
= list_entry(bpq_devices
.next
, struct bpqdev
, bpq_list
);
633 bpq_free_device(bpq
->axdev
);
638 MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
639 MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
640 MODULE_LICENSE("GPL");
641 module_init(bpq_init_driver
);
642 module_exit(bpq_cleanup_driver
);