patch-2.3.21 linux/drivers/net/wan/lapbether.c

• Lines: 572
• Date: Mon Oct 11 10:13:25 1999
• Orig file: v2.3.20/linux/drivers/net/wan/lapbether.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.20/linux/drivers/net/wan/lapbether.c linux/drivers/net/wan/lapbether.c
@@ -0,0 +1,571 @@
+/*
+ *	"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
+ */
+
+#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/segment.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/stat.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/lapb.h>
+#include <linux/init.h>
+
+static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
+
+static int lapbeth_rcv(struct sk_buff *, struct net_device *, struct packet_type *);
+static int lapbeth_device_event(struct notifier_block *, unsigned long, void *);
+
+static struct packet_type lapbeth_packet_type = {
+	0,		/* ntohs(ETH_P_DEC),*/
+	0,		/* copy */
+	lapbeth_rcv,
+	NULL,
+	NULL,
+};
+
+static struct notifier_block lapbeth_dev_notifier = {
+	lapbeth_device_event,
+	0
+};
+
+
+#define MAXLAPBDEV 100
+
+static struct lapbethdev {
+	struct lapbethdev *next;
+	char   ethname[14];		/* ether device name */
+	struct net_device *ethdev;		/* link to ethernet device */
+	struct net_device axdev;		/* lapbeth device (lapb#) */
+	struct net_device_stats stats;	/* some statistics */
+} *lapbeth_devices = NULL;
+
+
+/* ------------------------------------------------------------------------ */
+
+
+/*
+ *	Get the ethernet device for a LAPB device
+ */
+static __inline__ struct net_device *lapbeth_get_ether_dev(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth;
+	
+	lapbeth = (struct lapbethdev *)dev->priv;
+
+	return (lapbeth != NULL) ? lapbeth->ethdev : NULL;
+}
+
+/*
+ *	Get the LAPB device for the ethernet device
+ */
+static __inline__ struct net_device *lapbeth_get_x25_dev(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth;
+
+	for (lapbeth = lapbeth_devices; lapbeth != NULL; lapbeth = lapbeth->next)
+		if (lapbeth->ethdev == dev)
+			return &lapbeth->axdev;
+
+	return NULL;
+}
+
+static __inline__ int dev_is_ethdev(struct net_device *dev)
+{
+	return (
+			dev->type == ARPHRD_ETHER
+			&& strncmp(dev->name, "dummy", 5)
+	);
+}
+
+/*
+ *	Sanity check: remove all devices that ceased to exists and
+ *	return '1' if the given LAPB device was affected.
+ */
+static int lapbeth_check_devices(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth, *lapbeth_prev;
+	int result = 0;
+	unsigned long flags;
+	
+	save_flags(flags);
+	cli();
+
+	lapbeth_prev = NULL;
+
+	for (lapbeth = lapbeth_devices; lapbeth != NULL; lapbeth = lapbeth->next) {
+		if (!dev_get(lapbeth->ethname)) {
+			if (lapbeth_prev)
+				lapbeth_prev->next = lapbeth->next;
+			else
+				lapbeth_devices = lapbeth->next;
+				
+			if (&lapbeth->axdev == dev)
+				result = 1;
+
+			unregister_netdev(&lapbeth->axdev);
+			kfree(lapbeth);
+		}
+
+		lapbeth_prev = lapbeth;
+	}
+	
+	restore_flags(flags);
+	
+	return result;
+}
+
+
+/* ------------------------------------------------------------------------ */
+
+
+/*
+ *	Receive a LAPB frame via an ethernet interface.
+ */
+static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype)
+{
+	int len, err;
+	struct lapbethdev *lapbeth;
+
+	skb->sk = NULL;		/* Initially we don't know who it's for */
+	
+	dev = lapbeth_get_x25_dev(dev);
+
+	if (dev == NULL || dev->start == 0) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	lapbeth = (struct lapbethdev *)dev->priv;
+
+	lapbeth->stats.rx_packets++;
+
+	len = skb->data[0] + skb->data[1] * 256;
+
+	skb_pull(skb, 2);	/* Remove the length bytes */
+	skb_trim(skb, len);	/* Set the length of the data */
+
+	if ((err = lapb_data_received(lapbeth, skb)) != LAPB_OK) {
+		kfree_skb(skb);
+		printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
+	}
+
+	return 0;
+}
+
+static void lapbeth_data_indication(void *token, struct sk_buff *skb)
+{
+	struct lapbethdev *lapbeth = (struct lapbethdev *)token;
+	unsigned char *ptr;
+
+	ptr  = skb_push(skb, 1);
+	*ptr = 0x00;
+
+	skb->dev      = &lapbeth->axdev;
+	skb->protocol = htons(ETH_P_X25);
+	skb->mac.raw  = skb->data;
+	skb->pkt_type = PACKET_HOST;
+
+	netif_rx(skb);
+}
+
+/*
+ * 	Send a LAPB frame via an ethernet interface
+ */
+static int lapbeth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct lapbethdev *lapbeth;
+	int err;
+	
+	lapbeth = (struct lapbethdev *)dev->priv;
+
+	/*
+	 * Just to be *really* sure not to send anything if the interface
+	 * is down, the ethernet device may have gone.
+	 */
+	if (!dev->start) {
+		lapbeth_check_devices(dev);
+		kfree_skb(skb);
+		return -ENODEV;
+	}
+
+	switch (skb->data[0]) {
+		case 0x00:
+			break;
+		case 0x01:
+			if ((err = lapb_connect_request(lapbeth)) != LAPB_OK)
+				printk(KERN_ERR "lapbeth: lapb_connect_request error - %d\n", err);
+			kfree_skb(skb);
+			return 0;
+		case 0x02:
+			if ((err = lapb_disconnect_request(lapbeth)) != LAPB_OK)
+				printk(KERN_ERR "lapbeth: lapb_disconnect_request err - %d\n", err);
+			kfree_skb(skb);
+			return 0;
+		default:
+			kfree_skb(skb);
+			return 0;
+	}
+
+	skb_pull(skb, 1);
+
+	if ((err = lapb_data_request(lapbeth, skb)) != LAPB_OK) {
+		printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err);
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+	
+static void lapbeth_data_transmit(void *token, struct sk_buff *skb)
+{
+	struct lapbethdev *lapbeth = (struct lapbethdev *)token;
+	unsigned char *ptr;
+	struct net_device *dev;
+	int size;
+
+	skb->protocol = htons(ETH_P_X25);
+
+	size = skb->len;
+
+	ptr = skb_push(skb, 2);
+
+	*ptr++ = size % 256;
+	*ptr++ = size / 256;
+
+	lapbeth->stats.tx_packets++;
+
+	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(void *token, int reason)
+{
+	struct lapbethdev *lapbeth = (struct lapbethdev *)token;
+	struct sk_buff *skb;
+	unsigned char *ptr;
+
+	if ((skb = dev_alloc_skb(1)) == NULL) {
+		printk(KERN_ERR "lapbeth: out of memory\n");
+		return;
+	}
+
+	ptr  = skb_put(skb, 1);
+	*ptr = 0x01;
+
+	skb->dev      = &lapbeth->axdev;
+	skb->protocol = htons(ETH_P_X25);
+	skb->mac.raw  = skb->data;
+	skb->pkt_type = PACKET_HOST;
+
+	netif_rx(skb);
+}
+
+static void lapbeth_disconnected(void *token, int reason)
+{
+	struct lapbethdev *lapbeth = (struct lapbethdev *)token;
+	struct sk_buff *skb;
+	unsigned char *ptr;
+
+	if ((skb = dev_alloc_skb(1)) == NULL) {
+		printk(KERN_ERR "lapbeth: out of memory\n");
+		return;
+	}
+
+	ptr  = skb_put(skb, 1);
+	*ptr = 0x02;
+
+	skb->dev      = &lapbeth->axdev;
+	skb->protocol = htons(ETH_P_X25);
+	skb->mac.raw  = skb->data;
+	skb->pkt_type = PACKET_HOST;
+
+	netif_rx(skb);
+}
+
+/*
+ *	Statistics
+ */
+static struct net_device_stats *lapbeth_get_stats(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth;
+
+	lapbeth = (struct lapbethdev *)dev->priv;
+
+	return &lapbeth->stats;
+}
+
+/*
+ *	Set AX.25 callsign
+ */
+static int lapbeth_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;
+}
+
+static int lapbeth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	return -EINVAL;
+}
+
+/*
+ * open/close a device
+ */
+static int lapbeth_open(struct net_device *dev)
+{
+	struct lapb_register_struct lapbeth_callbacks;
+	struct lapbethdev *lapbeth;
+	int err;
+
+	if (lapbeth_check_devices(dev))
+		return -ENODEV;		/* oops, it's gone */
+	
+	dev->tbusy = 0;
+	dev->start = 1;
+
+	lapbeth = (struct lapbethdev *)dev->priv;
+
+	lapbeth_callbacks.connect_confirmation    = lapbeth_connected;
+	lapbeth_callbacks.connect_indication      = lapbeth_connected;
+	lapbeth_callbacks.disconnect_confirmation = lapbeth_disconnected;
+	lapbeth_callbacks.disconnect_indication   = lapbeth_disconnected;
+	lapbeth_callbacks.data_indication         = lapbeth_data_indication;
+	lapbeth_callbacks.data_transmit           = lapbeth_data_transmit;
+
+	if ((err = lapb_register(lapbeth, &lapbeth_callbacks)) != LAPB_OK) {
+		printk(KERN_ERR "lapbeth: lapb_register error - %d\n", err);
+		dev->tbusy = 1;
+		dev->start = 0;
+		return -ENODEV;
+	}
+
+	MOD_INC_USE_COUNT;
+
+	return 0;
+}
+
+static int lapbeth_close(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth;
+	int err;
+
+	dev->tbusy = 1;
+	dev->start = 0;
+
+	lapbeth = (struct lapbethdev *)dev->priv;
+
+	if ((err = lapb_unregister(lapbeth)) != LAPB_OK)
+		printk(KERN_ERR "lapbeth: lapb_unregister error - %d\n", err);
+
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+static int lapbeth_dev_init(struct net_device *dev)
+{
+	return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+/*
+ *	Setup a new device.
+ */
+static int lapbeth_new_device(struct net_device *dev)
+{
+	int k;
+	unsigned char *buf;
+	struct lapbethdev *lapbeth, *lapbeth2;
+	
+	if ((lapbeth = kmalloc(sizeof(struct lapbethdev), GFP_KERNEL)) == NULL)
+		return -ENOMEM;
+		
+	memset(lapbeth, 0, sizeof(struct lapbethdev));
+	
+	lapbeth->ethdev = dev;
+
+	lapbeth->ethname[sizeof(lapbeth->ethname)-1] = '\0';
+	strncpy(lapbeth->ethname, dev->name, sizeof(lapbeth->ethname)-1);
+
+	dev = &lapbeth->axdev;
+	buf = kmalloc(14, GFP_KERNEL);
+
+	for (k = 0; k < MAXLAPBDEV; k++) {
+		struct net_device *odev;
+
+		sprintf(buf, "lapb%d", k);
+
+		if ((odev = __dev_get_by_name(buf)) == NULL || lapbeth_check_devices(odev))
+			break;
+	}
+
+	if (k == MAXLAPBDEV) {
+		kfree(lapbeth);
+		return -ENODEV;
+	}
+	
+	dev->priv = (void *)lapbeth;	/* pointer back */
+	dev->name = buf;
+	dev->init = lapbeth_dev_init;
+
+	if (register_netdev(dev) != 0) {
+		kfree(lapbeth);
+                return -EIO;
+        }
+
+	dev_init_buffers(dev);
+
+	dev->hard_start_xmit = lapbeth_xmit;
+	dev->open	     = lapbeth_open;
+	dev->stop	     = lapbeth_close;
+	dev->set_mac_address = lapbeth_set_mac_address;
+	dev->get_stats	     = lapbeth_get_stats;
+	dev->do_ioctl	     = lapbeth_ioctl;
+
+	dev->flags      = 0;
+
+	dev->type            = ARPHRD_X25;
+	dev->hard_header_len = 3;
+	dev->mtu             = 1000;
+	dev->addr_len        = 0;
+
+	cli();
+
+	if (lapbeth_devices == NULL) {
+		lapbeth_devices = lapbeth;
+	} else {
+		for (lapbeth2 = lapbeth_devices; lapbeth2->next != NULL; lapbeth2 = lapbeth2->next);
+		lapbeth2->next = lapbeth;
+	}
+	
+	sti();
+
+	return 0;
+}
+
+
+/*
+ *	Handle device status changes.
+ */
+static int lapbeth_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;
+
+	lapbeth_check_devices(NULL);
+
+	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 */
+			if ((dev = lapbeth_get_x25_dev(dev)) != NULL)
+				dev_close(dev);
+			break;
+
+		default:
+			break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+
+/* ------------------------------------------------------------------------ */
+
+/*
+ * Initialize driver. To be called from af_ax25 if not compiled as a
+ * module
+ */
+int lapbeth_init(void)
+{
+	struct net_device *dev;
+
+	lapbeth_packet_type.type  = htons(ETH_P_DEC);
+	dev_add_pack(&lapbeth_packet_type);
+
+	register_netdevice_notifier(&lapbeth_dev_notifier);
+
+	printk(KERN_INFO "LAPB Ethernet driver version 0.01\n");
+
+	read_lock_bh(&dev_base_lock);
+	for (dev = dev_base; dev != NULL; dev = dev->next) {
+		if (dev_is_ethdev(dev)) {
+			read_unlock_bh(&dev_base_lock);
+			lapbeth_new_device(dev);
+			read_lock_bh(&dev_base_lock);
+		}
+	}
+	read_unlock_bh(&dev_base_lock);
+
+	return 0;
+}
+
+#ifdef MODULE
+EXPORT_NO_SYMBOLS;
+
+MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
+MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
+
+int init_module(void)
+{
+	return lapbeth_init();
+}
+
+void cleanup_module(void)
+{
+	struct lapbethdev *lapbeth;
+
+	dev_remove_pack(&lapbeth_packet_type);
+
+	unregister_netdevice_notifier(&lapbeth_dev_notifier);
+
+	for (lapbeth = lapbeth_devices; lapbeth != NULL; lapbeth = lapbeth->next)
+		unregister_netdev(&lapbeth->axdev);
+}
+#endif