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/etherdevice.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 *);
99 static struct packet_type bpq_packet_type = {
100 .type = __constant_htons(ETH_P_BPQ),
104 static struct notifier_block bpq_dev_notifier = {
105 .notifier_call =bpq_device_event,
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 char dest_addr[6]; /* ether destination address */
114 char acpt_addr[6]; /* accept ether frames from this address only */
117 static LIST_HEAD(bpq_devices);
120 * bpqether network devices are paired with ethernet devices below them, so
121 * form a special "super class" of normal ethernet devices; split their locks
122 * off into a separate class since they always nest.
124 static struct lock_class_key bpq_netdev_xmit_lock_key;
125 static struct lock_class_key bpq_netdev_addr_lock_key;
127 static void bpq_set_lockdep_class_one(struct net_device *dev,
128 struct netdev_queue *txq,
131 lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
134 static void bpq_set_lockdep_class(struct net_device *dev)
136 lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
137 netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
140 /* ------------------------------------------------------------------------ */
144 * Get the ethernet device for a BPQ device
146 static inline struct net_device *bpq_get_ether_dev(struct net_device *dev)
148 struct bpqdev *bpq = netdev_priv(dev);
150 return bpq ? bpq->ethdev : NULL;
154 * Get the BPQ device for the ethernet device
156 static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev)
160 list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) {
161 if (bpq->ethdev == dev)
167 static inline int dev_is_ethdev(struct net_device *dev)
170 dev->type == ARPHRD_ETHER
171 && strncmp(dev->name, "dummy", 5)
175 /* ------------------------------------------------------------------------ */
179 * Receive an AX.25 frame via an ethernet interface.
181 static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
188 if (dev_net(dev) != &init_net)
191 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
194 if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
198 dev = bpq_get_ax25_dev(dev);
200 if (dev == NULL || !netif_running(dev))
204 * if we want to accept frames from just one ethernet device
205 * we check the source address of the sender.
208 bpq = netdev_priv(dev);
212 if (!(bpq->acpt_addr[0] & 0x01) &&
213 memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN))
216 if (skb_cow(skb, sizeof(struct ethhdr)))
219 len = skb->data[0] + skb->data[1] * 256 - 5;
221 skb_pull(skb, 2); /* Remove the length bytes */
222 skb_trim(skb, len); /* Set the length of the data */
224 dev->stats.rx_packets++;
225 dev->stats.rx_bytes += len;
227 ptr = skb_push(skb, 1);
230 skb->protocol = ax25_type_trans(skb, dev);
247 * Send an AX.25 frame via an ethernet interface
249 static int bpq_xmit(struct sk_buff *skb, struct net_device *dev)
251 struct sk_buff *newskb;
257 * Just to be *really* sure not to send anything if the interface
258 * is down, the ethernet device may have gone.
260 if (!netif_running(dev)) {
269 * The AX.25 code leaves enough room for the ethernet header, but
272 if (skb_headroom(skb) < AX25_BPQ_HEADER_LEN) { /* Ough! */
273 if ((newskb = skb_realloc_headroom(skb, AX25_BPQ_HEADER_LEN)) == NULL) {
274 printk(KERN_WARNING "bpqether: out of memory\n");
280 skb_set_owner_w(newskb, skb->sk);
286 ptr = skb_push(skb, 2);
288 *ptr++ = (size + 5) % 256;
289 *ptr++ = (size + 5) / 256;
291 bpq = netdev_priv(dev);
293 if ((dev = bpq_get_ether_dev(dev)) == NULL) {
294 dev->stats.tx_dropped++;
299 skb->protocol = ax25_type_trans(skb, dev);
300 skb_reset_network_header(skb);
301 dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
302 dev->stats.tx_packets++;
303 dev->stats.tx_bytes+=skb->len;
306 netif_wake_queue(dev);
313 static int bpq_set_mac_address(struct net_device *dev, void *addr)
315 struct sockaddr *sa = (struct sockaddr *)addr;
317 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
324 * SIOCSBPQETHOPT reserved for enhancements
325 * SIOCSBPQETHADDR set the destination and accepted
326 * source ethernet address (broadcast
327 * or multicast: accept all)
329 static int bpq_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
331 struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
332 struct bpqdev *bpq = netdev_priv(dev);
335 if (!capable(CAP_NET_ADMIN))
340 if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
343 case SIOCGBPQETHPARAM:
344 case SIOCSBPQETHPARAM:
351 case SIOCSBPQETHADDR:
352 if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
354 if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
366 * open/close a device
368 static int bpq_open(struct net_device *dev)
370 netif_start_queue(dev);
374 static int bpq_close(struct net_device *dev)
376 netif_stop_queue(dev);
381 /* ------------------------------------------------------------------------ */
387 static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
390 struct bpqdev *bpqdev;
395 return SEQ_START_TOKEN;
397 list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
404 static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
410 if (v == SEQ_START_TOKEN)
411 p = rcu_dereference(bpq_devices.next);
413 p = rcu_dereference(((struct bpqdev *)v)->bpq_list.next);
415 return (p == &bpq_devices) ? NULL
416 : list_entry(p, struct bpqdev, bpq_list);
419 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",
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 = dev_alloc_name(ndev, ndev->name);
525 err = register_netdevice(ndev);
528 bpq_set_lockdep_class(ndev);
530 /* List protected by RTNL */
531 list_add_rcu(&bpq->bpq_list, &bpq_devices);
541 static void bpq_free_device(struct net_device *ndev)
543 struct bpqdev *bpq = netdev_priv(ndev);
545 dev_put(bpq->ethdev);
546 list_del_rcu(&bpq->bpq_list);
548 unregister_netdevice(ndev);
552 * Handle device status changes.
554 static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr)
556 struct net_device *dev = (struct net_device *)ptr;
558 if (dev_net(dev) != &init_net)
561 if (!dev_is_ethdev(dev))
565 case NETDEV_UP: /* new ethernet device -> new BPQ interface */
566 if (bpq_get_ax25_dev(dev) == NULL)
570 case NETDEV_DOWN: /* ethernet device closed -> close BPQ interface */
571 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
575 case NETDEV_UNREGISTER: /* ethernet device removed -> free BPQ interface */
576 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
577 bpq_free_device(dev);
587 /* ------------------------------------------------------------------------ */
590 * Initialize driver. To be called from af_ax25 if not compiled as a
593 static int __init bpq_init_driver(void)
595 #ifdef CONFIG_PROC_FS
596 if (!proc_net_fops_create(&init_net, "bpqether", S_IRUGO, &bpq_info_fops)) {
598 "bpq: cannot create /proc/net/bpqether entry.\n");
601 #endif /* CONFIG_PROC_FS */
603 dev_add_pack(&bpq_packet_type);
605 register_netdevice_notifier(&bpq_dev_notifier);
612 static void __exit bpq_cleanup_driver(void)
616 dev_remove_pack(&bpq_packet_type);
618 unregister_netdevice_notifier(&bpq_dev_notifier);
620 proc_net_remove(&init_net, "bpqether");
623 while (!list_empty(&bpq_devices)) {
624 bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
625 bpq_free_device(bpq->axdev);
630 MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
631 MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
632 MODULE_LICENSE("GPL");
633 module_init(bpq_init_driver);
634 module_exit(bpq_cleanup_driver);