diff options
Diffstat (limited to 'drivers/net/hamradio/bpqether.c')
| -rw-r--r-- | drivers/net/hamradio/bpqether.c | 643 |
1 files changed, 643 insertions, 0 deletions
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c new file mode 100644 index 000000000000..ef1a359e2273 --- /dev/null +++ b/drivers/net/hamradio/bpqether.c @@ -0,0 +1,643 @@ +/* + * 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/config.h> +#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/if_ether.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 <linux/bpqether.h> + +static char banner[] __initdata = KERN_INFO "AX.25: bpqether driver version 004\n"; + +static unsigned char ax25_bcast[AX25_ADDR_LEN] = + {'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, '0' << 1}; +static unsigned char ax25_defaddr[AX25_ADDR_LEN] = + {'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, '1' << 1}; + +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 *); +static int bpq_device_event(struct notifier_block *, unsigned long, void *); +static const char *bpq_print_ethaddr(const unsigned char *); + +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#) */ + struct net_device_stats stats; /* some statistics */ + char dest_addr[6]; /* ether destination address */ + char acpt_addr[6]; /* accept ether frames from this address only */ +}; + +static LIST_HEAD(bpq_devices); + + +/* ------------------------------------------------------------------------ */ + + +/* + * 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(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) +{ + int len; + char * ptr; + struct ethhdr *eth; + struct bpqdev *bpq; + + 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 */ + + bpq->stats.rx_packets++; + bpq->stats.rx_bytes += len; + + ptr = skb_push(skb, 1); + *ptr = 0; + + skb->dev = dev; + skb->protocol = htons(ETH_P_AX25); + skb->mac.raw = skb->data; + skb->pkt_type = PACKET_HOST; + + netif_rx(skb); + dev->last_rx = jiffies; +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; + } + + skb->protocol = htons(ETH_P_AX25); + + 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) { + bpq->stats.tx_dropped++; + kfree_skb(skb); + return -ENODEV; + } + + skb->dev = dev; + skb->nh.raw = skb->data; + dev->hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0); + bpq->stats.tx_packets++; + bpq->stats.tx_bytes+=skb->len; + + dev_queue_xmit(skb); + netif_wake_queue(dev); + return 0; +} + +/* + * Statistics + */ +static struct net_device_stats *bpq_get_stats(struct net_device *dev) +{ + struct bpqdev *bpq = netdev_priv(dev); + + return &bpq->stats; +} + +/* + * 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 const char * bpq_print_ethaddr(const unsigned char *e) +{ + static char buf[18]; + + sprintf(buf, "%2.2X:%2.2X:%2.2X:%2.2X:%2.2X:%2.2X", + e[0], e[1], e[2], e[3], e[4], e[5]); + + return buf; +} + +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(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 = bpq_devices.next; + else + p = ((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 %s ", + bpqdev->axdev->name, bpqdev->ethdev->name, + bpq_print_ethaddr(bpqdev->dest_addr)); + + seq_printf(seq, "%s\n", + (bpqdev->acpt_addr[0] & 0x01) ? "*" + : bpq_print_ethaddr(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 struct file_operations bpq_info_fops = { + .owner = THIS_MODULE, + .open = bpq_info_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + + +/* ------------------------------------------------------------------------ */ + + +static void bpq_setup(struct net_device *dev) +{ + + dev->hard_start_xmit = bpq_xmit; + dev->open = bpq_open; + dev->stop = bpq_close; + dev->set_mac_address = bpq_set_mac_address; + dev->get_stats = bpq_get_stats; + dev->do_ioctl = bpq_ioctl; + 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->hard_header = ax25_encapsulate; + dev->rebuild_header = ax25_rebuild_header; +#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; + + /* 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_is_ethdev(dev)) + return NOTIFY_DONE; + + rcu_read_lock(); + + 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; + } + rcu_read_unlock(); + + 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("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("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); |