472 lines
10 KiB
C
472 lines
10 KiB
C
/*
|
|
* "LAPB via ethernet" driver release 001
|
|
*
|
|
* This code REQUIRES 2.1.15 or higher/ NET3.038
|
|
*
|
|
* 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 LAPB over Ethernet.
|
|
*
|
|
* This driver can use any ethernet destination address, and can be
|
|
* limited to accept frames from one dedicated ethernet card only.
|
|
*
|
|
* History
|
|
* LAPBETH 001 Jonathan Naylor Cloned from bpqether.c
|
|
* 2000-10-29 Henner Eisen lapb_data_indication() return status.
|
|
* 2000-11-14 Henner Eisen dev_hold/put, NETDEV_GOING_DOWN support
|
|
*/
|
|
|
|
#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 <linux/inet.h>
|
|
#include <linux/netdevice.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/stat.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/module.h>
|
|
#include <linux/lapb.h>
|
|
#include <linux/init.h>
|
|
|
|
#include <net/x25device.h>
|
|
|
|
static char bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
|
|
|
|
/* If this number is made larger, check that the temporary string buffer
|
|
* in lapbeth_new_device is large enough to store the probe device name.*/
|
|
#define MAXLAPBDEV 100
|
|
|
|
struct lapbethdev {
|
|
struct list_head node;
|
|
struct net_device *ethdev; /* link to ethernet device */
|
|
struct net_device *axdev; /* lapbeth device (lapb#) */
|
|
struct net_device_stats stats; /* some statistics */
|
|
};
|
|
|
|
static LIST_HEAD(lapbeth_devices);
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
/*
|
|
* Get the LAPB device for the ethernet device
|
|
*/
|
|
static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
|
|
{
|
|
struct lapbethdev *lapbeth;
|
|
|
|
list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
|
|
if (lapbeth->ethdev == dev)
|
|
return lapbeth;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static __inline__ int dev_is_ethdev(struct net_device *dev)
|
|
{
|
|
return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
/*
|
|
* Receive a LAPB frame via an ethernet interface.
|
|
*/
|
|
static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
|
|
{
|
|
int len, err;
|
|
struct lapbethdev *lapbeth;
|
|
|
|
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, 2))
|
|
goto drop;
|
|
|
|
rcu_read_lock();
|
|
lapbeth = lapbeth_get_x25_dev(dev);
|
|
if (!lapbeth)
|
|
goto drop_unlock;
|
|
if (!netif_running(lapbeth->axdev))
|
|
goto drop_unlock;
|
|
|
|
lapbeth->stats.rx_packets++;
|
|
|
|
len = skb->data[0] + skb->data[1] * 256;
|
|
lapbeth->stats.rx_bytes += len;
|
|
|
|
skb_pull(skb, 2); /* Remove the length bytes */
|
|
skb_trim(skb, len); /* Set the length of the data */
|
|
|
|
if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) {
|
|
printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
|
|
goto drop_unlock;
|
|
}
|
|
out:
|
|
rcu_read_unlock();
|
|
return 0;
|
|
drop_unlock:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
drop:
|
|
kfree_skb(skb);
|
|
return 0;
|
|
}
|
|
|
|
static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
|
|
{
|
|
unsigned char *ptr;
|
|
|
|
skb_push(skb, 1);
|
|
|
|
if (skb_cow(skb, 1))
|
|
return NET_RX_DROP;
|
|
|
|
ptr = skb->data;
|
|
*ptr = 0x00;
|
|
|
|
skb->protocol = x25_type_trans(skb, dev);
|
|
skb->dev->last_rx = jiffies;
|
|
return netif_rx(skb);
|
|
}
|
|
|
|
/*
|
|
* Send a LAPB frame via an ethernet interface
|
|
*/
|
|
static int lapbeth_xmit(struct sk_buff *skb, struct net_device *dev)
|
|
{
|
|
int err = -ENODEV;
|
|
|
|
/*
|
|
* Just to be *really* sure not to send anything if the interface
|
|
* is down, the ethernet device may have gone.
|
|
*/
|
|
if (!netif_running(dev)) {
|
|
goto drop;
|
|
}
|
|
|
|
switch (skb->data[0]) {
|
|
case 0x00:
|
|
err = 0;
|
|
break;
|
|
case 0x01:
|
|
if ((err = lapb_connect_request(dev)) != LAPB_OK)
|
|
printk(KERN_ERR "lapbeth: lapb_connect_request "
|
|
"error: %d\n", err);
|
|
goto drop_ok;
|
|
case 0x02:
|
|
if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
|
|
printk(KERN_ERR "lapbeth: lapb_disconnect_request "
|
|
"err: %d\n", err);
|
|
/* Fall thru */
|
|
default:
|
|
goto drop_ok;
|
|
}
|
|
|
|
skb_pull(skb, 1);
|
|
|
|
if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
|
|
printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err);
|
|
err = -ENOMEM;
|
|
goto drop;
|
|
}
|
|
err = 0;
|
|
out:
|
|
return err;
|
|
drop_ok:
|
|
err = 0;
|
|
drop:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
|
|
{
|
|
struct lapbethdev *lapbeth = netdev_priv(ndev);
|
|
unsigned char *ptr;
|
|
struct net_device *dev;
|
|
int size = skb->len;
|
|
|
|
skb->protocol = htons(ETH_P_X25);
|
|
|
|
ptr = skb_push(skb, 2);
|
|
|
|
*ptr++ = size % 256;
|
|
*ptr++ = size / 256;
|
|
|
|
lapbeth->stats.tx_packets++;
|
|
lapbeth->stats.tx_bytes += size;
|
|
|
|
skb->dev = dev = lapbeth->ethdev;
|
|
|
|
dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
|
|
|
|
dev_queue_xmit(skb);
|
|
}
|
|
|
|
static void lapbeth_connected(struct net_device *dev, int reason)
|
|
{
|
|
unsigned char *ptr;
|
|
struct sk_buff *skb = dev_alloc_skb(1);
|
|
|
|
if (!skb) {
|
|
printk(KERN_ERR "lapbeth: out of memory\n");
|
|
return;
|
|
}
|
|
|
|
ptr = skb_put(skb, 1);
|
|
*ptr = 0x01;
|
|
|
|
skb->protocol = x25_type_trans(skb, dev);
|
|
skb->dev->last_rx = jiffies;
|
|
netif_rx(skb);
|
|
}
|
|
|
|
static void lapbeth_disconnected(struct net_device *dev, int reason)
|
|
{
|
|
unsigned char *ptr;
|
|
struct sk_buff *skb = dev_alloc_skb(1);
|
|
|
|
if (!skb) {
|
|
printk(KERN_ERR "lapbeth: out of memory\n");
|
|
return;
|
|
}
|
|
|
|
ptr = skb_put(skb, 1);
|
|
*ptr = 0x02;
|
|
|
|
skb->protocol = x25_type_trans(skb, dev);
|
|
skb->dev->last_rx = jiffies;
|
|
netif_rx(skb);
|
|
}
|
|
|
|
/*
|
|
* Statistics
|
|
*/
|
|
static struct net_device_stats *lapbeth_get_stats(struct net_device *dev)
|
|
{
|
|
struct lapbethdev *lapbeth = netdev_priv(dev);
|
|
return &lapbeth->stats;
|
|
}
|
|
|
|
/*
|
|
* Set AX.25 callsign
|
|
*/
|
|
static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
|
|
{
|
|
struct sockaddr *sa = addr;
|
|
memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static struct lapb_register_struct lapbeth_callbacks = {
|
|
.connect_confirmation = lapbeth_connected,
|
|
.connect_indication = lapbeth_connected,
|
|
.disconnect_confirmation = lapbeth_disconnected,
|
|
.disconnect_indication = lapbeth_disconnected,
|
|
.data_indication = lapbeth_data_indication,
|
|
.data_transmit = lapbeth_data_transmit,
|
|
|
|
};
|
|
|
|
/*
|
|
* open/close a device
|
|
*/
|
|
static int lapbeth_open(struct net_device *dev)
|
|
{
|
|
int err;
|
|
|
|
if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
|
|
printk(KERN_ERR "lapbeth: lapb_register error - %d\n", err);
|
|
return -ENODEV;
|
|
}
|
|
|
|
netif_start_queue(dev);
|
|
return 0;
|
|
}
|
|
|
|
static int lapbeth_close(struct net_device *dev)
|
|
{
|
|
int err;
|
|
|
|
netif_stop_queue(dev);
|
|
|
|
if ((err = lapb_unregister(dev)) != LAPB_OK)
|
|
printk(KERN_ERR "lapbeth: lapb_unregister error - %d\n", err);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
static void lapbeth_setup(struct net_device *dev)
|
|
{
|
|
dev->hard_start_xmit = lapbeth_xmit;
|
|
dev->open = lapbeth_open;
|
|
dev->stop = lapbeth_close;
|
|
dev->destructor = free_netdev;
|
|
dev->set_mac_address = lapbeth_set_mac_address;
|
|
dev->get_stats = lapbeth_get_stats;
|
|
dev->type = ARPHRD_X25;
|
|
dev->hard_header_len = 3;
|
|
dev->mtu = 1000;
|
|
dev->addr_len = 0;
|
|
}
|
|
|
|
/*
|
|
* Setup a new device.
|
|
*/
|
|
static int lapbeth_new_device(struct net_device *dev)
|
|
{
|
|
struct net_device *ndev;
|
|
struct lapbethdev *lapbeth;
|
|
int rc = -ENOMEM;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d",
|
|
lapbeth_setup);
|
|
if (!ndev)
|
|
goto out;
|
|
|
|
lapbeth = netdev_priv(ndev);
|
|
lapbeth->axdev = ndev;
|
|
|
|
dev_hold(dev);
|
|
lapbeth->ethdev = dev;
|
|
|
|
rc = dev_alloc_name(ndev, ndev->name);
|
|
if (rc < 0)
|
|
goto fail;
|
|
|
|
rc = -EIO;
|
|
if (register_netdevice(ndev))
|
|
goto fail;
|
|
|
|
list_add_rcu(&lapbeth->node, &lapbeth_devices);
|
|
rc = 0;
|
|
out:
|
|
return rc;
|
|
fail:
|
|
dev_put(dev);
|
|
free_netdev(ndev);
|
|
kfree(lapbeth);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Free a lapb network device.
|
|
*/
|
|
static void lapbeth_free_device(struct lapbethdev *lapbeth)
|
|
{
|
|
dev_put(lapbeth->ethdev);
|
|
list_del_rcu(&lapbeth->node);
|
|
unregister_netdevice(lapbeth->axdev);
|
|
}
|
|
|
|
/*
|
|
* Handle device status changes.
|
|
*
|
|
* Called from notifier with RTNL held.
|
|
*/
|
|
static int lapbeth_device_event(struct notifier_block *this,
|
|
unsigned long event, void *ptr)
|
|
{
|
|
struct lapbethdev *lapbeth;
|
|
struct net_device *dev = 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 LAPB interface */
|
|
if (lapbeth_get_x25_dev(dev) == NULL)
|
|
lapbeth_new_device(dev);
|
|
break;
|
|
case NETDEV_DOWN:
|
|
/* ethernet device closed -> close LAPB interface */
|
|
lapbeth = lapbeth_get_x25_dev(dev);
|
|
if (lapbeth)
|
|
dev_close(lapbeth->axdev);
|
|
break;
|
|
case NETDEV_UNREGISTER:
|
|
/* ethernet device disappears -> remove LAPB interface */
|
|
lapbeth = lapbeth_get_x25_dev(dev);
|
|
if (lapbeth)
|
|
lapbeth_free_device(lapbeth);
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
|
|
static struct packet_type lapbeth_packet_type = {
|
|
.type = __constant_htons(ETH_P_DEC),
|
|
.func = lapbeth_rcv,
|
|
};
|
|
|
|
static struct notifier_block lapbeth_dev_notifier = {
|
|
.notifier_call = lapbeth_device_event,
|
|
};
|
|
|
|
static char banner[] __initdata = KERN_INFO "LAPB Ethernet driver version 0.02\n";
|
|
|
|
static int __init lapbeth_init_driver(void)
|
|
{
|
|
dev_add_pack(&lapbeth_packet_type);
|
|
|
|
register_netdevice_notifier(&lapbeth_dev_notifier);
|
|
|
|
printk(banner);
|
|
|
|
return 0;
|
|
}
|
|
module_init(lapbeth_init_driver);
|
|
|
|
static void __exit lapbeth_cleanup_driver(void)
|
|
{
|
|
struct lapbethdev *lapbeth;
|
|
struct list_head *entry, *tmp;
|
|
|
|
dev_remove_pack(&lapbeth_packet_type);
|
|
unregister_netdevice_notifier(&lapbeth_dev_notifier);
|
|
|
|
rtnl_lock();
|
|
list_for_each_safe(entry, tmp, &lapbeth_devices) {
|
|
lapbeth = list_entry(entry, struct lapbethdev, node);
|
|
|
|
dev_put(lapbeth->ethdev);
|
|
unregister_netdevice(lapbeth->axdev);
|
|
}
|
|
rtnl_unlock();
|
|
}
|
|
module_exit(lapbeth_cleanup_driver);
|
|
|
|
MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
|
|
MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
|
|
MODULE_LICENSE("GPL");
|