| /* |
| * G8BPQ compatible "AX.25 via ethernet" driver release 004 |
| * |
| * This code REQUIRES 2.0.0 or higher/ NET3.029 |
| * |
| * This module: |
| * This module is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * This is a "pseudo" network driver to allow AX.25 over Ethernet |
| * using G8BPQ encapsulation. It has been extracted from the protocol |
| * implementation because |
| * |
| * - things got unreadable within the protocol stack |
| * - to cure the protocol stack from "feature-ism" |
| * - a protocol implementation shouldn't need to know on |
| * which hardware it is running |
| * - user-level programs like the AX.25 utilities shouldn't |
| * need to know about the hardware. |
| * - IP over ethernet encapsulated AX.25 was impossible |
| * - rxecho.c did not work |
| * - to have room for extensions |
| * - it just deserves to "live" as an own driver |
| * |
| * This driver can use any ethernet destination address, and can be |
| * limited to accept frames from one dedicated ethernet card only. |
| * |
| * Note that the driver sets up the BPQ devices automagically on |
| * startup or (if started before the "insmod" of an ethernet device) |
| * on "ifconfig up". It hopefully will remove the BPQ on "rmmod"ing |
| * the ethernet device (in fact: as soon as another ethernet or bpq |
| * device gets "ifconfig"ured). |
| * |
| * I have heard that several people are thinking of experiments |
| * with highspeed packet radio using existing ethernet cards. |
| * Well, this driver is prepared for this purpose, just add |
| * your tx key control and a txdelay / tailtime algorithm, |
| * probably some buffering, and /voila/... |
| * |
| * History |
| * BPQ 001 Joerg(DL1BKE) Extracted BPQ code from AX.25 |
| * protocol stack and added my own |
| * yet existing patches |
| * BPQ 002 Joerg(DL1BKE) Scan network device list on |
| * startup. |
| * BPQ 003 Joerg(DL1BKE) Ethernet destination address |
| * and accepted source address |
| * can be configured by an ioctl() |
| * call. |
| * Fixed to match Linux networking |
| * changes - 2.1.15. |
| * BPQ 004 Joerg(DL1BKE) Fixed to not lock up on ifconfig. |
| */ |
| |
| #include <linux/errno.h> |
| #include <linux/types.h> |
| #include <linux/socket.h> |
| #include <linux/in.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/net.h> |
| #include <net/ax25.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/etherdevice.h> |
| #include <linux/if_arp.h> |
| #include <linux/skbuff.h> |
| #include <net/sock.h> |
| #include <asm/system.h> |
| #include <asm/uaccess.h> |
| #include <linux/mm.h> |
| #include <linux/interrupt.h> |
| #include <linux/notifier.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/stat.h> |
| #include <linux/netfilter.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/rtnetlink.h> |
| |
| #include <net/ip.h> |
| #include <net/arp.h> |
| #include <net/net_namespace.h> |
| |
| #include <linux/bpqether.h> |
| |
| static char banner[] __initdata = KERN_INFO "AX.25: bpqether driver version 004\n"; |
| |
| static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF}; |
| |
| static char bpq_eth_addr[6]; |
| |
| static int bpq_rcv(struct sk_buff *, struct net_device *, struct packet_type *, struct net_device *); |
| static int bpq_device_event(struct notifier_block *, unsigned long, void *); |
| |
| static struct packet_type bpq_packet_type = { |
| .type = __constant_htons(ETH_P_BPQ), |
| .func = bpq_rcv, |
| }; |
| |
| static struct notifier_block bpq_dev_notifier = { |
| .notifier_call =bpq_device_event, |
| }; |
| |
| |
| struct bpqdev { |
| struct list_head bpq_list; /* list of bpq devices chain */ |
| struct net_device *ethdev; /* link to ethernet device */ |
| struct net_device *axdev; /* bpq device (bpq#) */ |
| char dest_addr[6]; /* ether destination address */ |
| char acpt_addr[6]; /* accept ether frames from this address only */ |
| }; |
| |
| static LIST_HEAD(bpq_devices); |
| |
| /* |
| * bpqether network devices are paired with ethernet devices below them, so |
| * form a special "super class" of normal ethernet devices; split their locks |
| * off into a separate class since they always nest. |
| */ |
| static struct lock_class_key bpq_netdev_xmit_lock_key; |
| static struct lock_class_key bpq_netdev_addr_lock_key; |
| |
| static void bpq_set_lockdep_class_one(struct net_device *dev, |
| struct netdev_queue *txq, |
| void *_unused) |
| { |
| lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key); |
| } |
| |
| static void bpq_set_lockdep_class(struct net_device *dev) |
| { |
| lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key); |
| netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL); |
| } |
| |
| /* ------------------------------------------------------------------------ */ |
| |
| |
| /* |
| * Get the ethernet device for a BPQ device |
| */ |
| static inline struct net_device *bpq_get_ether_dev(struct net_device *dev) |
| { |
| struct bpqdev *bpq = netdev_priv(dev); |
| |
| return bpq ? bpq->ethdev : NULL; |
| } |
| |
| /* |
| * Get the BPQ device for the ethernet device |
| */ |
| static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev) |
| { |
| struct bpqdev *bpq; |
| |
| list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) { |
| if (bpq->ethdev == dev) |
| return bpq->axdev; |
| } |
| return NULL; |
| } |
| |
| static inline int dev_is_ethdev(struct net_device *dev) |
| { |
| return ( |
| dev->type == ARPHRD_ETHER |
| && strncmp(dev->name, "dummy", 5) |
| ); |
| } |
| |
| /* ------------------------------------------------------------------------ */ |
| |
| |
| /* |
| * Receive an AX.25 frame via an ethernet interface. |
| */ |
| static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev) |
| { |
| int len; |
| char * ptr; |
| struct ethhdr *eth; |
| struct bpqdev *bpq; |
| |
| if (dev_net(dev) != &init_net) |
| goto drop; |
| |
| if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) |
| return NET_RX_DROP; |
| |
| if (!pskb_may_pull(skb, sizeof(struct ethhdr))) |
| goto drop; |
| |
| rcu_read_lock(); |
| dev = bpq_get_ax25_dev(dev); |
| |
| if (dev == NULL || !netif_running(dev)) |
| goto drop_unlock; |
| |
| /* |
| * if we want to accept frames from just one ethernet device |
| * we check the source address of the sender. |
| */ |
| |
| bpq = netdev_priv(dev); |
| |
| eth = eth_hdr(skb); |
| |
| if (!(bpq->acpt_addr[0] & 0x01) && |
| memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN)) |
| goto drop_unlock; |
| |
| if (skb_cow(skb, sizeof(struct ethhdr))) |
| goto drop_unlock; |
| |
| len = skb->data[0] + skb->data[1] * 256 - 5; |
| |
| skb_pull(skb, 2); /* Remove the length bytes */ |
| skb_trim(skb, len); /* Set the length of the data */ |
| |
| dev->stats.rx_packets++; |
| dev->stats.rx_bytes += len; |
| |
| ptr = skb_push(skb, 1); |
| *ptr = 0; |
| |
| skb->protocol = ax25_type_trans(skb, dev); |
| netif_rx(skb); |
| unlock: |
| |
| rcu_read_unlock(); |
| |
| return 0; |
| drop_unlock: |
| kfree_skb(skb); |
| goto unlock; |
| |
| drop: |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| /* |
| * Send an AX.25 frame via an ethernet interface |
| */ |
| static int bpq_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct sk_buff *newskb; |
| unsigned char *ptr; |
| struct bpqdev *bpq; |
| int size; |
| |
| /* |
| * Just to be *really* sure not to send anything if the interface |
| * is down, the ethernet device may have gone. |
| */ |
| if (!netif_running(dev)) { |
| kfree_skb(skb); |
| return -ENODEV; |
| } |
| |
| skb_pull(skb, 1); |
| size = skb->len; |
| |
| /* |
| * The AX.25 code leaves enough room for the ethernet header, but |
| * sendto() does not. |
| */ |
| if (skb_headroom(skb) < AX25_BPQ_HEADER_LEN) { /* Ough! */ |
| if ((newskb = skb_realloc_headroom(skb, AX25_BPQ_HEADER_LEN)) == NULL) { |
| printk(KERN_WARNING "bpqether: out of memory\n"); |
| kfree_skb(skb); |
| return -ENOMEM; |
| } |
| |
| if (skb->sk != NULL) |
| skb_set_owner_w(newskb, skb->sk); |
| |
| kfree_skb(skb); |
| skb = newskb; |
| } |
| |
| ptr = skb_push(skb, 2); |
| |
| *ptr++ = (size + 5) % 256; |
| *ptr++ = (size + 5) / 256; |
| |
| bpq = netdev_priv(dev); |
| |
| if ((dev = bpq_get_ether_dev(dev)) == NULL) { |
| dev->stats.tx_dropped++; |
| kfree_skb(skb); |
| return -ENODEV; |
| } |
| |
| skb->protocol = ax25_type_trans(skb, dev); |
| skb_reset_network_header(skb); |
| dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0); |
| dev->stats.tx_packets++; |
| dev->stats.tx_bytes+=skb->len; |
| |
| dev_queue_xmit(skb); |
| netif_wake_queue(dev); |
| return 0; |
| } |
| |
| /* |
| * Set AX.25 callsign |
| */ |
| static int bpq_set_mac_address(struct net_device *dev, void *addr) |
| { |
| struct sockaddr *sa = (struct sockaddr *)addr; |
| |
| memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); |
| |
| return 0; |
| } |
| |
| /* Ioctl commands |
| * |
| * SIOCSBPQETHOPT reserved for enhancements |
| * SIOCSBPQETHADDR set the destination and accepted |
| * source ethernet address (broadcast |
| * or multicast: accept all) |
| */ |
| static int bpq_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) |
| { |
| struct bpq_ethaddr __user *ethaddr = ifr->ifr_data; |
| struct bpqdev *bpq = netdev_priv(dev); |
| struct bpq_req req; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| switch (cmd) { |
| case SIOCSBPQETHOPT: |
| if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req))) |
| return -EFAULT; |
| switch (req.cmd) { |
| case SIOCGBPQETHPARAM: |
| case SIOCSBPQETHPARAM: |
| default: |
| return -EINVAL; |
| } |
| |
| break; |
| |
| case SIOCSBPQETHADDR: |
| if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN)) |
| return -EFAULT; |
| if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN)) |
| return -EFAULT; |
| break; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * open/close a device |
| */ |
| static int bpq_open(struct net_device *dev) |
| { |
| netif_start_queue(dev); |
| return 0; |
| } |
| |
| static int bpq_close(struct net_device *dev) |
| { |
| netif_stop_queue(dev); |
| return 0; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| |
| |
| /* |
| * Proc filesystem |
| */ |
| static void *bpq_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| int i = 1; |
| struct bpqdev *bpqdev; |
| |
| rcu_read_lock(); |
| |
| if (*pos == 0) |
| return SEQ_START_TOKEN; |
| |
| list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) { |
| if (i == *pos) |
| return bpqdev; |
| } |
| return NULL; |
| } |
| |
| static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct list_head *p; |
| |
| ++*pos; |
| |
| if (v == SEQ_START_TOKEN) |
| p = rcu_dereference(bpq_devices.next); |
| else |
| p = rcu_dereference(((struct bpqdev *)v)->bpq_list.next); |
| |
| return (p == &bpq_devices) ? NULL |
| : list_entry(p, struct bpqdev, bpq_list); |
| } |
| |
| static void bpq_seq_stop(struct seq_file *seq, void *v) |
| { |
| rcu_read_unlock(); |
| } |
| |
| |
| static int bpq_seq_show(struct seq_file *seq, void *v) |
| { |
| if (v == SEQ_START_TOKEN) |
| seq_puts(seq, |
| "dev ether destination accept from\n"); |
| else { |
| const struct bpqdev *bpqdev = v; |
| |
| seq_printf(seq, "%-5s %-10s %pM ", |
| bpqdev->axdev->name, bpqdev->ethdev->name, |
| bpqdev->dest_addr); |
| |
| if (is_multicast_ether_addr(bpqdev->acpt_addr)) |
| seq_printf(seq, "*\n"); |
| else |
| seq_printf(seq, "%pM\n", bpqdev->acpt_addr); |
| |
| } |
| return 0; |
| } |
| |
| static struct seq_operations bpq_seqops = { |
| .start = bpq_seq_start, |
| .next = bpq_seq_next, |
| .stop = bpq_seq_stop, |
| .show = bpq_seq_show, |
| }; |
| |
| static int bpq_info_open(struct inode *inode, struct file *file) |
| { |
| return seq_open(file, &bpq_seqops); |
| } |
| |
| static const struct file_operations bpq_info_fops = { |
| .owner = THIS_MODULE, |
| .open = bpq_info_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| |
| static const struct net_device_ops bpq_netdev_ops = { |
| .ndo_open = bpq_open, |
| .ndo_stop = bpq_close, |
| .ndo_start_xmit = bpq_xmit, |
| .ndo_set_mac_address = bpq_set_mac_address, |
| .ndo_do_ioctl = bpq_ioctl, |
| }; |
| |
| static void bpq_setup(struct net_device *dev) |
| { |
| dev->netdev_ops = &bpq_netdev_ops; |
| dev->destructor = free_netdev; |
| |
| memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN); |
| memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN); |
| |
| dev->flags = 0; |
| |
| #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) |
| dev->header_ops = &ax25_header_ops; |
| #endif |
| |
| dev->type = ARPHRD_AX25; |
| dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN; |
| dev->mtu = AX25_DEF_PACLEN; |
| dev->addr_len = AX25_ADDR_LEN; |
| |
| } |
| |
| /* |
| * Setup a new device. |
| */ |
| static int bpq_new_device(struct net_device *edev) |
| { |
| int err; |
| struct net_device *ndev; |
| struct bpqdev *bpq; |
| |
| ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d", |
| bpq_setup); |
| if (!ndev) |
| return -ENOMEM; |
| |
| |
| bpq = netdev_priv(ndev); |
| dev_hold(edev); |
| bpq->ethdev = edev; |
| bpq->axdev = ndev; |
| |
| memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr)); |
| memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr)); |
| |
| err = dev_alloc_name(ndev, ndev->name); |
| if (err < 0) |
| goto error; |
| |
| err = register_netdevice(ndev); |
| if (err) |
| goto error; |
| bpq_set_lockdep_class(ndev); |
| |
| /* List protected by RTNL */ |
| list_add_rcu(&bpq->bpq_list, &bpq_devices); |
| return 0; |
| |
| error: |
| dev_put(edev); |
| free_netdev(ndev); |
| return err; |
| |
| } |
| |
| static void bpq_free_device(struct net_device *ndev) |
| { |
| struct bpqdev *bpq = netdev_priv(ndev); |
| |
| dev_put(bpq->ethdev); |
| list_del_rcu(&bpq->bpq_list); |
| |
| unregister_netdevice(ndev); |
| } |
| |
| /* |
| * Handle device status changes. |
| */ |
| static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr) |
| { |
| struct net_device *dev = (struct net_device *)ptr; |
| |
| if (dev_net(dev) != &init_net) |
| return NOTIFY_DONE; |
| |
| if (!dev_is_ethdev(dev)) |
| return NOTIFY_DONE; |
| |
| switch (event) { |
| case NETDEV_UP: /* new ethernet device -> new BPQ interface */ |
| if (bpq_get_ax25_dev(dev) == NULL) |
| bpq_new_device(dev); |
| break; |
| |
| case NETDEV_DOWN: /* ethernet device closed -> close BPQ interface */ |
| if ((dev = bpq_get_ax25_dev(dev)) != NULL) |
| dev_close(dev); |
| break; |
| |
| case NETDEV_UNREGISTER: /* ethernet device removed -> free BPQ interface */ |
| if ((dev = bpq_get_ax25_dev(dev)) != NULL) |
| bpq_free_device(dev); |
| break; |
| default: |
| break; |
| } |
| |
| return NOTIFY_DONE; |
| } |
| |
| |
| /* ------------------------------------------------------------------------ */ |
| |
| /* |
| * Initialize driver. To be called from af_ax25 if not compiled as a |
| * module |
| */ |
| static int __init bpq_init_driver(void) |
| { |
| #ifdef CONFIG_PROC_FS |
| if (!proc_net_fops_create(&init_net, "bpqether", S_IRUGO, &bpq_info_fops)) { |
| printk(KERN_ERR |
| "bpq: cannot create /proc/net/bpqether entry.\n"); |
| return -ENOENT; |
| } |
| #endif /* CONFIG_PROC_FS */ |
| |
| dev_add_pack(&bpq_packet_type); |
| |
| register_netdevice_notifier(&bpq_dev_notifier); |
| |
| printk(banner); |
| |
| return 0; |
| } |
| |
| static void __exit bpq_cleanup_driver(void) |
| { |
| struct bpqdev *bpq; |
| |
| dev_remove_pack(&bpq_packet_type); |
| |
| unregister_netdevice_notifier(&bpq_dev_notifier); |
| |
| proc_net_remove(&init_net, "bpqether"); |
| |
| rtnl_lock(); |
| while (!list_empty(&bpq_devices)) { |
| bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list); |
| bpq_free_device(bpq->axdev); |
| } |
| rtnl_unlock(); |
| } |
| |
| MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>"); |
| MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet"); |
| MODULE_LICENSE("GPL"); |
| module_init(bpq_init_driver); |
| module_exit(bpq_cleanup_driver); |