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/system.h>
73 #include <asm/uaccess.h>
75 #include <linux/interrupt.h>
76 #include <linux/notifier.h>
77 #include <linux/proc_fs.h>
78 #include <linux/seq_file.h>
79 #include <linux/stat.h>
80 #include <linux/netfilter.h>
81 #include <linux/module.h>
82 #include <linux/init.h>
83 #include <linux/rtnetlink.h>
87 #include <net/net_namespace.h>
89 #include <linux/bpqether.h>
91 static const char banner[] __initdata = KERN_INFO \
92 "AX.25: bpqether driver version 004\n";
94 static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
96 static char bpq_eth_addr[6];
98 static int bpq_rcv(struct sk_buff *, struct net_device *, struct packet_type *, struct net_device *);
99 static int bpq_device_event(struct notifier_block *, unsigned long, void *);
101 static struct packet_type bpq_packet_type __read_mostly = {
102 .type = cpu_to_be16(ETH_P_BPQ),
106 static struct notifier_block bpq_dev_notifier = {
107 .notifier_call =bpq_device_event,
112 struct list_head bpq_list; /* list of bpq devices chain */
113 struct net_device *ethdev; /* link to ethernet device */
114 struct net_device *axdev; /* bpq device (bpq#) */
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;
127 static struct lock_class_key bpq_netdev_addr_lock_key;
129 static void bpq_set_lockdep_class_one(struct net_device *dev,
130 struct netdev_queue *txq,
133 lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
136 static void bpq_set_lockdep_class(struct net_device *dev)
138 lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
139 netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
142 /* ------------------------------------------------------------------------ */
146 * Get the ethernet device for a BPQ device
148 static inline struct net_device *bpq_get_ether_dev(struct net_device *dev)
150 struct bpqdev *bpq = netdev_priv(dev);
152 return bpq ? bpq->ethdev : NULL;
156 * Get the BPQ device for the ethernet device
158 static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev)
162 list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) {
163 if (bpq->ethdev == dev)
169 static inline int dev_is_ethdev(struct net_device *dev)
171 return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
174 /* ------------------------------------------------------------------------ */
178 * Receive an AX.25 frame via an ethernet interface.
180 static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
187 if (!net_eq(dev_net(dev), &init_net))
190 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
193 if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
197 dev = bpq_get_ax25_dev(dev);
199 if (dev == NULL || !netif_running(dev))
203 * if we want to accept frames from just one ethernet device
204 * we check the source address of the sender.
207 bpq = netdev_priv(dev);
211 if (!(bpq->acpt_addr[0] & 0x01) &&
212 memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN))
215 if (skb_cow(skb, sizeof(struct ethhdr)))
218 len = skb->data[0] + skb->data[1] * 256 - 5;
220 skb_pull(skb, 2); /* Remove the length bytes */
221 skb_trim(skb, len); /* Set the length of the data */
223 dev->stats.rx_packets++;
224 dev->stats.rx_bytes += len;
226 ptr = skb_push(skb, 1);
229 skb->protocol = ax25_type_trans(skb, dev);
246 * Send an AX.25 frame via an ethernet interface
248 static netdev_tx_t bpq_xmit(struct sk_buff *skb, struct net_device *dev)
252 struct net_device *orig_dev;
256 * Just to be *really* sure not to send anything if the interface
257 * is down, the ethernet device may have gone.
259 if (!netif_running(dev)) {
264 skb_pull(skb, 1); /* Drop KISS byte */
268 * We're about to mess with the skb which may still shared with the
269 * generic networking code so unshare and ensure it's got enough
270 * space for the BPQ headers.
272 if (skb_cow(skb, AX25_BPQ_HEADER_LEN)) {
274 pr_err("bpqether: out of memory\n");
280 ptr = skb_push(skb, 2); /* Make space for length */
282 *ptr++ = (size + 5) % 256;
283 *ptr++ = (size + 5) / 256;
285 bpq = netdev_priv(dev);
288 if ((dev = bpq_get_ether_dev(dev)) == NULL) {
289 orig_dev->stats.tx_dropped++;
294 skb->protocol = ax25_type_trans(skb, dev);
295 skb_reset_network_header(skb);
296 dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
297 dev->stats.tx_packets++;
298 dev->stats.tx_bytes+=skb->len;
301 netif_wake_queue(dev);
308 static int bpq_set_mac_address(struct net_device *dev, void *addr)
310 struct sockaddr *sa = (struct sockaddr *)addr;
312 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
319 * SIOCSBPQETHOPT reserved for enhancements
320 * SIOCSBPQETHADDR set the destination and accepted
321 * source ethernet address (broadcast
322 * or multicast: accept all)
324 static int bpq_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
326 struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
327 struct bpqdev *bpq = netdev_priv(dev);
330 if (!capable(CAP_NET_ADMIN))
335 if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
338 case SIOCGBPQETHPARAM:
339 case SIOCSBPQETHPARAM:
346 case SIOCSBPQETHADDR:
347 if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
349 if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
361 * open/close a device
363 static int bpq_open(struct net_device *dev)
365 netif_start_queue(dev);
369 static int bpq_close(struct net_device *dev)
371 netif_stop_queue(dev);
376 /* ------------------------------------------------------------------------ */
382 static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
386 struct bpqdev *bpqdev;
391 return SEQ_START_TOKEN;
393 list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
400 static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
403 struct bpqdev *bpqdev = v;
407 if (v == SEQ_START_TOKEN)
408 p = rcu_dereference(list_next_rcu(&bpq_devices));
410 p = rcu_dereference(list_next_rcu(&bpqdev->bpq_list));
412 return (p == &bpq_devices) ? NULL
413 : list_entry(p, struct bpqdev, bpq_list);
416 static void bpq_seq_stop(struct seq_file *seq, void *v)
423 static int bpq_seq_show(struct seq_file *seq, void *v)
425 if (v == SEQ_START_TOKEN)
427 "dev ether destination accept from\n");
429 const struct bpqdev *bpqdev = v;
431 seq_printf(seq, "%-5s %-10s %pM ",
432 bpqdev->axdev->name, bpqdev->ethdev->name,
435 if (is_multicast_ether_addr(bpqdev->acpt_addr))
436 seq_printf(seq, "*\n");
438 seq_printf(seq, "%pM\n", bpqdev->acpt_addr);
444 static const struct seq_operations bpq_seqops = {
445 .start = bpq_seq_start,
446 .next = bpq_seq_next,
447 .stop = bpq_seq_stop,
448 .show = bpq_seq_show,
451 static int bpq_info_open(struct inode *inode, struct file *file)
453 return seq_open(file, &bpq_seqops);
456 static const struct file_operations bpq_info_fops = {
457 .owner = THIS_MODULE,
458 .open = bpq_info_open,
461 .release = seq_release,
465 /* ------------------------------------------------------------------------ */
467 static const struct net_device_ops bpq_netdev_ops = {
468 .ndo_open = bpq_open,
469 .ndo_stop = bpq_close,
470 .ndo_start_xmit = bpq_xmit,
471 .ndo_set_mac_address = bpq_set_mac_address,
472 .ndo_do_ioctl = bpq_ioctl,
475 static void bpq_setup(struct net_device *dev)
477 dev->netdev_ops = &bpq_netdev_ops;
478 dev->destructor = free_netdev;
480 memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
481 memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
485 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
486 dev->header_ops = &ax25_header_ops;
489 dev->type = ARPHRD_AX25;
490 dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
491 dev->mtu = AX25_DEF_PACLEN;
492 dev->addr_len = AX25_ADDR_LEN;
497 * Setup a new device.
499 static int bpq_new_device(struct net_device *edev)
502 struct net_device *ndev;
505 ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d",
511 bpq = netdev_priv(ndev);
516 memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
517 memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));
519 err = dev_alloc_name(ndev, ndev->name);
523 err = register_netdevice(ndev);
526 bpq_set_lockdep_class(ndev);
528 /* List protected by RTNL */
529 list_add_rcu(&bpq->bpq_list, &bpq_devices);
539 static void bpq_free_device(struct net_device *ndev)
541 struct bpqdev *bpq = netdev_priv(ndev);
543 dev_put(bpq->ethdev);
544 list_del_rcu(&bpq->bpq_list);
546 unregister_netdevice(ndev);
550 * Handle device status changes.
552 static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr)
554 struct net_device *dev = (struct net_device *)ptr;
556 if (!net_eq(dev_net(dev), &init_net))
559 if (!dev_is_ethdev(dev))
563 case NETDEV_UP: /* new ethernet device -> new BPQ interface */
564 if (bpq_get_ax25_dev(dev) == NULL)
568 case NETDEV_DOWN: /* ethernet device closed -> close BPQ interface */
569 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
573 case NETDEV_UNREGISTER: /* ethernet device removed -> free BPQ interface */
574 if ((dev = bpq_get_ax25_dev(dev)) != NULL)
575 bpq_free_device(dev);
585 /* ------------------------------------------------------------------------ */
588 * Initialize driver. To be called from af_ax25 if not compiled as a
591 static int __init bpq_init_driver(void)
593 #ifdef CONFIG_PROC_FS
594 if (!proc_net_fops_create(&init_net, "bpqether", S_IRUGO, &bpq_info_fops)) {
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 proc_net_remove(&init_net, "bpqether");
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);