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>
64 #include <linux/slab.h>
66 #include <linux/inet.h>
67 #include <linux/netdevice.h>
68 #include <linux/etherdevice.h>
69 #include <linux/if_arp.h>
70 #include <linux/skbuff.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 const char banner
[] __initconst
= KERN_INFO \
91 "AX.25: bpqether driver version 004\n";
93 static char bcast_addr
[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
95 static char bpq_eth_addr
[6];
97 static int bpq_rcv(struct sk_buff
*, struct net_device
*, struct packet_type
*, struct net_device
*);
98 static int bpq_device_event(struct notifier_block
*, unsigned long, void *);
100 static struct packet_type bpq_packet_type __read_mostly
= {
101 .type
= cpu_to_be16(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 char dest_addr
[6]; /* ether destination address */
115 char acpt_addr
[6]; /* accept ether frames from this address only */
118 static LIST_HEAD(bpq_devices
);
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.
125 static struct lock_class_key bpq_netdev_xmit_lock_key
;
126 static struct lock_class_key bpq_netdev_addr_lock_key
;
128 static void bpq_set_lockdep_class_one(struct net_device
*dev
,
129 struct netdev_queue
*txq
,
132 lockdep_set_class(&txq
->_xmit_lock
, &bpq_netdev_xmit_lock_key
);
135 static void bpq_set_lockdep_class(struct net_device
*dev
)
137 lockdep_set_class(&dev
->addr_list_lock
, &bpq_netdev_addr_lock_key
);
138 netdev_for_each_tx_queue(dev
, bpq_set_lockdep_class_one
, NULL
);
141 /* ------------------------------------------------------------------------ */
145 * Get the ethernet device for a BPQ device
147 static inline struct net_device
*bpq_get_ether_dev(struct net_device
*dev
)
149 struct bpqdev
*bpq
= netdev_priv(dev
);
151 return bpq
? bpq
->ethdev
: NULL
;
155 * Get the BPQ device for the ethernet device
157 static inline struct net_device
*bpq_get_ax25_dev(struct net_device
*dev
)
161 list_for_each_entry_rcu(bpq
, &bpq_devices
, bpq_list
) {
162 if (bpq
->ethdev
== dev
)
168 static inline int dev_is_ethdev(struct net_device
*dev
)
170 return dev
->type
== ARPHRD_ETHER
&& strncmp(dev
->name
, "dummy", 5);
173 /* ------------------------------------------------------------------------ */
177 * Receive an AX.25 frame via an ethernet interface.
179 static int bpq_rcv(struct sk_buff
*skb
, struct net_device
*dev
, struct packet_type
*ptype
, struct net_device
*orig_dev
)
186 if (!net_eq(dev_net(dev
), &init_net
))
189 if ((skb
= skb_share_check(skb
, GFP_ATOMIC
)) == NULL
)
192 if (!pskb_may_pull(skb
, sizeof(struct ethhdr
)))
196 dev
= bpq_get_ax25_dev(dev
);
198 if (dev
== NULL
|| !netif_running(dev
))
202 * if we want to accept frames from just one ethernet device
203 * we check the source address of the sender.
206 bpq
= netdev_priv(dev
);
210 if (!(bpq
->acpt_addr
[0] & 0x01) &&
211 !ether_addr_equal(eth
->h_source
, bpq
->acpt_addr
))
214 if (skb_cow(skb
, sizeof(struct ethhdr
)))
217 len
= skb
->data
[0] + skb
->data
[1] * 256 - 5;
219 skb_pull(skb
, 2); /* Remove the length bytes */
220 skb_trim(skb
, len
); /* Set the length of the data */
222 dev
->stats
.rx_packets
++;
223 dev
->stats
.rx_bytes
+= len
;
225 ptr
= skb_push(skb
, 1);
228 skb
->protocol
= ax25_type_trans(skb
, dev
);
245 * Send an AX.25 frame via an ethernet interface
247 static netdev_tx_t
bpq_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
251 struct net_device
*orig_dev
;
254 if (skb
->protocol
== htons(ETH_P_IP
))
255 return ax25_ip_xmit(skb
);
258 * Just to be *really* sure not to send anything if the interface
259 * is down, the ethernet device may have gone.
261 if (!netif_running(dev
)) {
266 skb_pull(skb
, 1); /* Drop KISS byte */
270 * We're about to mess with the skb which may still shared with the
271 * generic networking code so unshare and ensure it's got enough
272 * space for the BPQ headers.
274 if (skb_cow(skb
, AX25_BPQ_HEADER_LEN
)) {
276 pr_err("bpqether: out of memory\n");
282 ptr
= skb_push(skb
, 2); /* Make space for length */
284 *ptr
++ = (size
+ 5) % 256;
285 *ptr
++ = (size
+ 5) / 256;
287 bpq
= netdev_priv(dev
);
290 if ((dev
= bpq_get_ether_dev(dev
)) == NULL
) {
291 orig_dev
->stats
.tx_dropped
++;
296 skb
->protocol
= ax25_type_trans(skb
, dev
);
297 skb_reset_network_header(skb
);
298 dev_hard_header(skb
, dev
, ETH_P_BPQ
, bpq
->dest_addr
, NULL
, 0);
299 dev
->stats
.tx_packets
++;
300 dev
->stats
.tx_bytes
+=skb
->len
;
303 netif_wake_queue(dev
);
310 static int bpq_set_mac_address(struct net_device
*dev
, void *addr
)
312 struct sockaddr
*sa
= (struct sockaddr
*)addr
;
314 memcpy(dev
->dev_addr
, sa
->sa_data
, dev
->addr_len
);
321 * SIOCSBPQETHOPT reserved for enhancements
322 * SIOCSBPQETHADDR set the destination and accepted
323 * source ethernet address (broadcast
324 * or multicast: accept all)
326 static int bpq_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
328 struct bpq_ethaddr __user
*ethaddr
= ifr
->ifr_data
;
329 struct bpqdev
*bpq
= netdev_priv(dev
);
332 if (!capable(CAP_NET_ADMIN
))
337 if (copy_from_user(&req
, ifr
->ifr_data
, sizeof(struct bpq_req
)))
340 case SIOCGBPQETHPARAM
:
341 case SIOCSBPQETHPARAM
:
348 case SIOCSBPQETHADDR
:
349 if (copy_from_user(bpq
->dest_addr
, ethaddr
->destination
, ETH_ALEN
))
351 if (copy_from_user(bpq
->acpt_addr
, ethaddr
->accept
, ETH_ALEN
))
363 * open/close a device
365 static int bpq_open(struct net_device
*dev
)
367 netif_start_queue(dev
);
371 static int bpq_close(struct net_device
*dev
)
373 netif_stop_queue(dev
);
378 /* ------------------------------------------------------------------------ */
384 static void *bpq_seq_start(struct seq_file
*seq
, loff_t
*pos
)
388 struct bpqdev
*bpqdev
;
393 return SEQ_START_TOKEN
;
395 list_for_each_entry_rcu(bpqdev
, &bpq_devices
, bpq_list
) {
402 static void *bpq_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
405 struct bpqdev
*bpqdev
= v
;
409 if (v
== SEQ_START_TOKEN
)
410 p
= rcu_dereference(list_next_rcu(&bpq_devices
));
412 p
= rcu_dereference(list_next_rcu(&bpqdev
->bpq_list
));
414 return (p
== &bpq_devices
) ? NULL
415 : list_entry(p
, struct bpqdev
, bpq_list
);
418 static void bpq_seq_stop(struct seq_file
*seq
, void *v
)
425 static int bpq_seq_show(struct seq_file
*seq
, void *v
)
427 if (v
== SEQ_START_TOKEN
)
429 "dev ether destination accept from\n");
431 const struct bpqdev
*bpqdev
= v
;
433 seq_printf(seq
, "%-5s %-10s %pM ",
434 bpqdev
->axdev
->name
, bpqdev
->ethdev
->name
,
437 if (is_multicast_ether_addr(bpqdev
->acpt_addr
))
438 seq_printf(seq
, "*\n");
440 seq_printf(seq
, "%pM\n", bpqdev
->acpt_addr
);
446 static const struct seq_operations bpq_seqops
= {
447 .start
= bpq_seq_start
,
448 .next
= bpq_seq_next
,
449 .stop
= bpq_seq_stop
,
450 .show
= bpq_seq_show
,
453 static int bpq_info_open(struct inode
*inode
, struct file
*file
)
455 return seq_open(file
, &bpq_seqops
);
458 static const struct file_operations bpq_info_fops
= {
459 .owner
= THIS_MODULE
,
460 .open
= bpq_info_open
,
463 .release
= seq_release
,
467 /* ------------------------------------------------------------------------ */
469 static const struct net_device_ops bpq_netdev_ops
= {
470 .ndo_open
= bpq_open
,
471 .ndo_stop
= bpq_close
,
472 .ndo_start_xmit
= bpq_xmit
,
473 .ndo_set_mac_address
= bpq_set_mac_address
,
474 .ndo_do_ioctl
= bpq_ioctl
,
477 static void bpq_setup(struct net_device
*dev
)
479 dev
->netdev_ops
= &bpq_netdev_ops
;
480 dev
->destructor
= free_netdev
;
482 memcpy(dev
->broadcast
, &ax25_bcast
, AX25_ADDR_LEN
);
483 memcpy(dev
->dev_addr
, &ax25_defaddr
, AX25_ADDR_LEN
);
487 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
488 dev
->header_ops
= &ax25_header_ops
;
491 dev
->type
= ARPHRD_AX25
;
492 dev
->hard_header_len
= AX25_MAX_HEADER_LEN
+ AX25_BPQ_HEADER_LEN
;
493 dev
->mtu
= AX25_DEF_PACLEN
;
494 dev
->addr_len
= AX25_ADDR_LEN
;
499 * Setup a new device.
501 static int bpq_new_device(struct net_device
*edev
)
504 struct net_device
*ndev
;
507 ndev
= alloc_netdev(sizeof(struct bpqdev
), "bpq%d", NET_NAME_UNKNOWN
,
513 bpq
= netdev_priv(ndev
);
518 memcpy(bpq
->dest_addr
, bcast_addr
, sizeof(bpq_eth_addr
));
519 memcpy(bpq
->acpt_addr
, bcast_addr
, sizeof(bpq_eth_addr
));
521 err
= register_netdevice(ndev
);
524 bpq_set_lockdep_class(ndev
);
526 /* List protected by RTNL */
527 list_add_rcu(&bpq
->bpq_list
, &bpq_devices
);
537 static void bpq_free_device(struct net_device
*ndev
)
539 struct bpqdev
*bpq
= netdev_priv(ndev
);
541 dev_put(bpq
->ethdev
);
542 list_del_rcu(&bpq
->bpq_list
);
544 unregister_netdevice(ndev
);
548 * Handle device status changes.
550 static int bpq_device_event(struct notifier_block
*this,
551 unsigned long event
, void *ptr
)
553 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
555 if (!net_eq(dev_net(dev
), &init_net
))
558 if (!dev_is_ethdev(dev
))
562 case NETDEV_UP
: /* new ethernet device -> new BPQ interface */
563 if (bpq_get_ax25_dev(dev
) == NULL
)
567 case NETDEV_DOWN
: /* ethernet device closed -> close BPQ interface */
568 if ((dev
= bpq_get_ax25_dev(dev
)) != NULL
)
572 case NETDEV_UNREGISTER
: /* ethernet device removed -> free BPQ interface */
573 if ((dev
= bpq_get_ax25_dev(dev
)) != NULL
)
574 bpq_free_device(dev
);
584 /* ------------------------------------------------------------------------ */
587 * Initialize driver. To be called from af_ax25 if not compiled as a
590 static int __init
bpq_init_driver(void)
592 #ifdef CONFIG_PROC_FS
593 if (!proc_create("bpqether", S_IRUGO
, init_net
.proc_net
,
596 "bpq: cannot create /proc/net/bpqether entry.\n");
599 #endif /* CONFIG_PROC_FS */
601 dev_add_pack(&bpq_packet_type
);
603 register_netdevice_notifier(&bpq_dev_notifier
);
610 static void __exit
bpq_cleanup_driver(void)
614 dev_remove_pack(&bpq_packet_type
);
616 unregister_netdevice_notifier(&bpq_dev_notifier
);
618 remove_proc_entry("bpqether", init_net
.proc_net
);
621 while (!list_empty(&bpq_devices
)) {
622 bpq
= list_entry(bpq_devices
.next
, struct bpqdev
, bpq_list
);
623 bpq_free_device(bpq
->axdev
);
628 MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
629 MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
630 MODULE_LICENSE("GPL");
631 module_init(bpq_init_driver
);
632 module_exit(bpq_cleanup_driver
);