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/config.h>
58 #include <linux/errno.h>
59 #include <linux/types.h>
60 #include <linux/socket.h>
62 #include <linux/kernel.h>
63 #include <linux/string.h>
64 #include <linux/net.h>
66 #include <linux/inet.h>
67 #include <linux/netdevice.h>
68 #include <linux/if_ether.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>
88 #include <linux/bpqether.h>
90 static char banner[] __initdata = KERN_INFO "AX.25: bpqether driver version 004\n";
92 static unsigned char ax25_bcast[AX25_ADDR_LEN] =
93 {'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, '0' << 1};
94 static unsigned char ax25_defaddr[AX25_ADDR_LEN] =
95 {'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, '1' << 1};
97 static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
99 static char bpq_eth_addr[6];
101 static int bpq_rcv(struct sk_buff *, struct net_device *, struct packet_type *);
102 static int bpq_device_event(struct notifier_block *, unsigned long, void *);
103 static const char *bpq_print_ethaddr(const unsigned char *);
105 static struct packet_type bpq_packet_type = {
106 .type = __constant_htons(ETH_P_BPQ),
110 static struct notifier_block bpq_dev_notifier = {
111 .notifier_call =bpq_device_event,
116 struct list_head bpq_list; /* list of bpq devices chain */
117 struct net_device *ethdev; /* link to ethernet device */
118 struct net_device *axdev; /* bpq device (bpq#) */
119 struct net_device_stats stats; /* some statistics */
120 char dest_addr[6]; /* ether destination address */
121 char acpt_addr[6]; /* accept ether frames from this address only */
124 static LIST_HEAD(bpq_devices);
127 /* ------------------------------------------------------------------------ */
131 * Get the ethernet device for a BPQ device
133 static inline struct net_device *bpq_get_ether_dev(struct net_device *dev)
135 struct bpqdev *bpq = netdev_priv(dev);
137 return bpq ? bpq->ethdev : NULL;
141 * Get the BPQ device for the ethernet device
143 static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev)
147 list_for_each_entry(bpq, &bpq_devices, bpq_list) {
148 if (bpq->ethdev == dev)
154 static inline int dev_is_ethdev(struct net_device *dev)
157 dev->type == ARPHRD_ETHER
158 && strncmp(dev->name, "dummy", 5)
162 /* ------------------------------------------------------------------------ */
166 * Receive an AX.25 frame via an ethernet interface.
168 static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype)
175 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
178 if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
182 dev = bpq_get_ax25_dev(dev);
184 if (dev == NULL || !netif_running(dev))
188 * if we want to accept frames from just one ethernet device
189 * we check the source address of the sender.
192 bpq = netdev_priv(dev);
196 if (!(bpq->acpt_addr[0] & 0x01) &&
197 memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN))
200 if (skb_cow(skb, sizeof(struct ethhdr)))
203 len = skb->data[0] + skb->data[1] * 256 - 5;
205 skb_pull(skb, 2); /* Remove the length bytes */
206 skb_trim(skb, len); /* Set the length of the data */
208 bpq->stats.rx_packets++;
209 bpq->stats.rx_bytes += len;
211 ptr = skb_push(skb, 1);
215 skb->protocol = htons(ETH_P_AX25);
216 skb->mac.raw = skb->data;
217 skb->pkt_type = PACKET_HOST;
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 skb->protocol = htons(ETH_P_AX25);
277 ptr = skb_push(skb, 2);
279 *ptr++ = (size + 5) % 256;
280 *ptr++ = (size + 5) / 256;
282 bpq = netdev_priv(dev);
284 if ((dev = bpq_get_ether_dev(dev)) == NULL) {
285 bpq->stats.tx_dropped++;
291 skb->nh.raw = skb->data;
292 dev->hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
293 bpq->stats.tx_packets++;
294 bpq->stats.tx_bytes+=skb->len;
297 netif_wake_queue(dev);
304 static struct net_device_stats *bpq_get_stats(struct net_device *dev)
306 struct bpqdev *bpq = netdev_priv(dev);
314 static int bpq_set_mac_address(struct net_device *dev, void *addr)
316 struct sockaddr *sa = (struct sockaddr *)addr;
318 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
325 * SIOCSBPQETHOPT reserved for enhancements
326 * SIOCSBPQETHADDR set the destination and accepted
327 * source ethernet address (broadcast
328 * or multicast: accept all)
330 static int bpq_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
332 struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
333 struct bpqdev *bpq = netdev_priv(dev);
336 if (!capable(CAP_NET_ADMIN))
341 if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
344 case SIOCGBPQETHPARAM:
345 case SIOCSBPQETHPARAM:
352 case SIOCSBPQETHADDR:
353 if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
355 if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
367 * open/close a device
369 static int bpq_open(struct net_device *dev)
371 netif_start_queue(dev);
375 static int bpq_close(struct net_device *dev)
377 netif_stop_queue(dev);
382 /* ------------------------------------------------------------------------ */
388 static const char * bpq_print_ethaddr(const unsigned char *e)
392 sprintf(buf, "%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X",
393 e[0], e[1], e[2], e[3], e[4], e[5]);
398 static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
401 struct bpqdev *bpqdev;
406 return SEQ_START_TOKEN;
408 list_for_each_entry(bpqdev, &bpq_devices, bpq_list) {
415 static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
421 if (v == SEQ_START_TOKEN)
422 p = bpq_devices.next;
424 p = ((struct bpqdev *)v)->bpq_list.next;
426 return (p == &bpq_devices) ? NULL
427 : list_entry(p, struct bpqdev, bpq_list);
430 static void bpq_seq_stop(struct seq_file *seq, void *v)
436 static int bpq_seq_show(struct seq_file *seq, void *v)
438 if (v == SEQ_START_TOKEN)
440 "dev ether destination accept from\n");
442 const struct bpqdev *bpqdev = v;
444 seq_printf(seq, "%-5s %-10s %s ",
445 bpqdev->axdev->name, bpqdev->ethdev->name,
446 bpq_print_ethaddr(bpqdev->dest_addr));
448 seq_printf(seq, "%s\n",
449 (bpqdev->acpt_addr[0] & 0x01) ? "*"
450 : bpq_print_ethaddr(bpqdev->acpt_addr));
456 static struct seq_operations bpq_seqops = {
457 .start = bpq_seq_start,
458 .next = bpq_seq_next,
459 .stop = bpq_seq_stop,
460 .show = bpq_seq_show,
463 static int bpq_info_open(struct inode *inode, struct file *file)
465 return seq_open(file, &bpq_seqops);
468 static struct file_operations bpq_info_fops = {
469 .owner = THIS_MODULE,
470 .open = bpq_info_open,
473 .release = seq_release,
477 /* ------------------------------------------------------------------------ */
480 static void bpq_setup(struct net_device *dev)
483 dev->hard_start_xmit = bpq_xmit;
484 dev->open = bpq_open;
485 dev->stop = bpq_close;
486 dev->set_mac_address = bpq_set_mac_address;
487 dev->get_stats = bpq_get_stats;
488 dev->do_ioctl = bpq_ioctl;
489 dev->destructor = free_netdev;
491 memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN);
492 memcpy(dev->dev_addr, ax25_defaddr, AX25_ADDR_LEN);
496 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
497 dev->hard_header = ax25_encapsulate;
498 dev->rebuild_header = ax25_rebuild_header;
501 dev->type = ARPHRD_AX25;
502 dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
503 dev->mtu = AX25_DEF_PACLEN;
504 dev->addr_len = AX25_ADDR_LEN;
509 * Setup a new device.
511 static int bpq_new_device(struct net_device *edev)
514 struct net_device *ndev;
517 ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d",
523 bpq = netdev_priv(ndev);
528 memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
529 memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));
531 err = dev_alloc_name(ndev, ndev->name);
535 err = register_netdevice(ndev);
539 /* List protected by RTNL */
540 list_add_rcu(&bpq->bpq_list, &bpq_devices);
550 static void bpq_free_device(struct net_device *ndev)
552 struct bpqdev *bpq = netdev_priv(ndev);
554 dev_put(bpq->ethdev);
555 list_del_rcu(&bpq->bpq_list);
557 unregister_netdevice(ndev);
561 * Handle device status changes.
563 static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr)
565 struct net_device *dev = (struct net_device *)ptr;
567 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);
596 /* ------------------------------------------------------------------------ */
599 * Initialize driver. To be called from af_ax25 if not compiled as a
602 static int __init bpq_init_driver(void)
604 #ifdef CONFIG_PROC_FS
605 if (!proc_net_fops_create("bpqether", S_IRUGO, &bpq_info_fops)) {
607 "bpq: cannot create /proc/net/bpqether entry.\n");
610 #endif /* CONFIG_PROC_FS */
612 dev_add_pack(&bpq_packet_type);
614 register_netdevice_notifier(&bpq_dev_notifier);
621 static void __exit bpq_cleanup_driver(void)
625 dev_remove_pack(&bpq_packet_type);
627 unregister_netdevice_notifier(&bpq_dev_notifier);
629 proc_net_remove("bpqether");
632 while (!list_empty(&bpq_devices)) {
633 bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
634 bpq_free_device(bpq->axdev);
639 MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
640 MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
641 MODULE_LICENSE("GPL");
642 module_init(bpq_init_driver);
643 module_exit(bpq_cleanup_driver);