patch-2.1.9 linux/drivers/net/bpqether.c

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diff -u --recursive --new-file v2.1.8/linux/drivers/net/bpqether.c linux/drivers/net/bpqether.c
@@ -0,0 +1,690 @@
+/*
+ *	G8BPQ compatible "AX.25 via ethernet" driver release 003
+ *
+ *	This is ALPHA test software. This code may break your machine, randomly 
+ *	fail to work with new releases, misbehave and/or generally screw up. 
+ *	It might even work. 
+ *
+ *	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.
+ */
+
+#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_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/firewall.h>
+#include <linux/module.h>
+#include <linux/net_alias.h>
+
+#include <net/ip.h>
+#include <net/arp.h>
+
+#include <linux/bpqether.h>
+
+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 device *, struct packet_type *);
+static int bpq_device_event(struct notifier_block *, unsigned long, void *);
+static char *bpq_print_ethaddr(unsigned char *);
+
+static struct packet_type bpq_packet_type = {
+	0,		/* ntohs(ETH_P_BPQ),*/
+	0,		/* copy */
+	bpq_rcv,
+	NULL,
+	NULL,
+};
+
+static struct notifier_block bpq_dev_notifier = {
+	bpq_device_event,
+	0
+};
+
+
+#define MAXBPQDEV 100
+
+static struct bpqdev {
+	struct bpqdev *next;
+	char   ethname[14];		/* ether device name */
+	struct device *ethdev;		/* link to ethernet device */
+	struct device axdev;		/* bpq device (bpq#) */
+	struct enet_statistics stats;	/* some statistics */
+	char   dest_addr[6];		/* ether destination address */
+	char   acpt_addr[6];		/* accept ether frames from this address only */
+} *bpq_devices = NULL;
+
+
+/* ------------------------------------------------------------------------ */
+
+
+/*
+ *	Get the ethernet device for a BPQ device
+ */
+static __inline__ struct device *bpq_get_ether_dev(struct device *dev)
+{
+	struct bpqdev *bpq;
+	
+	bpq = (struct bpqdev *)dev->priv;
+
+	return (bpq != NULL) ? bpq->ethdev : NULL;
+}
+
+/*
+ *	Get the BPQ device for the ethernet device
+ */
+static __inline__ struct device *bpq_get_ax25_dev(struct device *dev)
+{
+	struct bpqdev *bpq;
+
+	for (bpq = bpq_devices; bpq != NULL; bpq = bpq->next)
+		if (bpq->ethdev == dev)
+			return &bpq->axdev;
+
+	return NULL;
+}
+
+static __inline__ int dev_is_ethdev(struct device *dev)
+{
+	return (
+			dev->type == ARPHRD_ETHER
+			&& strncmp(dev->name, "dummy", 5)
+#ifdef CONFIG_NET_ALIAS
+			&& !net_alias_is(dev)
+#endif
+	);
+}
+
+/*
+ *	Sanity check: remove all devices that ceased to exists and
+ *	return '1' if the given BPQ device was affected.
+ */
+static int bpq_check_devices(struct device *dev)
+{
+	struct bpqdev *bpq, *bpq_prev;
+	int result = 0;
+	unsigned long flags;
+	
+	save_flags(flags);
+	cli();
+
+	bpq_prev = NULL;
+
+	for (bpq = bpq_devices; bpq != NULL; bpq = bpq->next) {
+		if (!dev_get(bpq->ethname)) {
+			if (bpq_prev)
+				bpq_prev->next = bpq->next;
+			else
+				bpq_devices = bpq->next;
+				
+			if (&bpq->axdev == dev)
+				result = 1;
+
+			unregister_netdev(&bpq->axdev);
+			kfree(bpq);
+		}
+
+		bpq_prev = bpq;
+	}
+	
+	restore_flags(flags);
+	
+	return result;
+}
+
+
+/* ------------------------------------------------------------------------ */
+
+
+/*
+ *	Receive an AX.25 frame via an ethernet interface.
+ */
+static int bpq_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *ptype)
+{
+	int len;
+	char * ptr;
+	struct ethhdr *eth = (struct ethhdr *)skb->mac.raw;
+	struct bpqdev *bpq;
+
+	skb->sk = NULL;		/* Initially we don't know who it's for */
+	
+	dev = bpq_get_ax25_dev(dev);
+
+	if (dev == NULL || dev->start == 0) {
+		kfree_skb(skb, FREE_READ);
+		return 0;
+	}
+
+	/*
+	 * if we want to accept frames from just one ethernet device
+	 * we check the source address of the sender.
+	 */
+
+	bpq = (struct bpqdev *)dev->priv;
+
+	if (!(bpq->acpt_addr[0] & 0x01) && memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN)) {
+		printk(KERN_DEBUG "bpqether: wrong dest %s\n", bpq_print_ethaddr(eth->h_source));
+		kfree_skb(skb, FREE_READ);
+		return 0;
+	}
+
+	((struct bpqdev *)dev->priv)->stats.rx_packets++;
+
+	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 */
+
+	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);
+
+	return 0;
+}
+
+/*
+ * 	Send an AX.25 frame via an ethernet interface
+ */
+static int bpq_xmit(struct sk_buff *skb, struct device *dev)
+{
+	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 (!dev->start) {
+		bpq_check_devices(dev);
+		dev_kfree_skb(skb, FREE_WRITE);
+		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! */
+		struct sk_buff *newskb = alloc_skb(skb->len + AX25_BPQ_HEADER_LEN, GFP_ATOMIC);
+
+		if (newskb == NULL) {			/* Argh! */
+			printk(KERN_WARNING "bpq_xmit: not enough space to add BPQ Ether header\n");
+			dev_kfree_skb(skb, FREE_WRITE);
+			return -ENOMEM;
+		}
+
+		newskb->free = 1;
+		newskb->arp  = 1;
+		newskb->sk   = skb->sk;
+
+		skb_reserve(newskb, AX25_BPQ_HEADER_LEN);
+		memcpy(skb_put(newskb, size), skb->data, size);
+		dev_kfree_skb(skb, FREE_WRITE);
+		skb = newskb;
+
+		if (skb->sk != NULL)
+			atomic_add(skb->truesize, &skb->sk->wmem_alloc);
+	}
+	
+	skb->protocol = htons(ETH_P_AX25);
+
+	ptr = skb_push(skb, 2);
+
+	*ptr++ = (size + 5) % 256;
+	*ptr++ = (size + 5) / 256;
+	
+	bpq = (struct bpqdev *)dev->priv;
+	bpq->stats.tx_packets++;
+	
+	if ((dev = bpq_get_ether_dev(dev)) == NULL) {
+		bpq->stats.tx_dropped++;
+		dev_kfree_skb(skb, FREE_WRITE);
+		return -ENODEV;
+	}
+
+	skb->dev = dev;
+	dev->hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
+
+	return dev->hard_start_xmit(skb, dev);
+}
+
+/*
+ *	Statistics
+ */
+static struct enet_statistics * bpq_get_stats(struct device *dev)
+{
+	struct bpqdev *bpq;
+
+	bpq = (struct bpqdev *)dev->priv;
+
+	return &bpq->stats;
+}
+
+
+/*
+ *	Rebuild header...
+ */
+static int bpq_rebuild_header(void *buff, struct device *dev, unsigned long raddr, struct sk_buff *skb)
+{
+	return ax25_rebuild_header((unsigned char *)buff, dev, raddr, skb);
+}
+
+/*
+ *	Set AX.25 callsign
+ */
+static int bpq_set_mac_address(struct 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 device *dev, struct ifreq *ifr, int cmd)
+{
+	int err;
+	struct bpq_ethaddr *ethaddr = (struct bpq_ethaddr *)ifr->ifr_data;
+	struct bpqdev *bpq = dev->priv;
+	struct bpq_req req;
+
+	if (!suser())
+		return -EPERM;
+	
+	if (bpq == NULL)		/* woops! */
+		return -ENODEV;
+	
+	switch (cmd) {
+		case SIOCSBPQETHOPT:
+			if ((err = verify_area(VERIFY_WRITE, ifr->ifr_data, sizeof(struct bpq_req))) != 0)
+				return err;
+			copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req));
+			switch (req.cmd) {
+				case SIOCGBPQETHPARAM:
+				case SIOCSBPQETHPARAM:
+				default:
+					return -EINVAL;
+			}
+			
+			break;
+			
+		case SIOCSBPQETHADDR:
+			if ((err = verify_area(VERIFY_READ, ethaddr, sizeof(struct bpq_ethaddr))) != 0)
+				return err;
+			copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN);
+			copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN);
+			break;
+
+		default:
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * open/close a device
+ */
+static int bpq_open(struct device *dev)
+{
+	if (bpq_check_devices(dev))
+		return -ENODEV;		/* oops, it's gone */
+	
+	dev->tbusy = 0;
+	dev->start = 1;
+
+	MOD_INC_USE_COUNT;
+
+	return 0;
+}
+
+static int bpq_close(struct device *dev)
+{
+	dev->tbusy = 1;
+	dev->start = 0;
+
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+/*
+ * currently unused
+ */
+static int bpq_dev_init(struct device *dev)
+{
+	return 0;
+}
+
+
+/* ------------------------------------------------------------------------ */
+
+
+/*
+ *	Proc filesystem
+ */
+static char * bpq_print_ethaddr(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;
+}
+
+int bpq_get_info(char *buffer, char **start, off_t offset, int length, int dummy)
+{
+	struct bpqdev *bpqdev;
+	int len     = 0;
+	off_t pos   = 0;
+	off_t begin = 0;
+  
+	cli();
+
+	len += sprintf(buffer, "dev   ether      destination        accept from\n");
+
+	for (bpqdev = bpq_devices; bpqdev != NULL; bpqdev = bpqdev->next) {
+		len += sprintf(buffer + len, "%-5s %-10s %s  ",
+			bpqdev->axdev.name, bpqdev->ethname,
+			bpq_print_ethaddr(bpqdev->dest_addr));
+
+		len += sprintf(buffer + len, "%s\n",
+			(bpqdev->acpt_addr[0] & 0x01) ? "*" : bpq_print_ethaddr(bpqdev->acpt_addr));
+
+		pos = begin + len;
+
+		if (pos < offset) {
+			len   = 0;
+			begin = pos;
+		}
+		
+		if (pos > offset + length)
+			break;
+	}
+
+	sti();
+
+	*start = buffer + (offset - begin);
+	len   -= (offset - begin);
+
+	if (len > length) len = length;
+
+	return len;
+} 
+
+
+/* ------------------------------------------------------------------------ */
+
+
+/*
+ *	Setup a new device.
+ */
+static int bpq_new_device(struct device *dev)
+{
+	int k;
+	unsigned char *buf;
+	struct bpqdev *bpq, *bpq2;
+	
+	if ((bpq = (struct bpqdev *)kmalloc(sizeof(struct bpqdev), GFP_KERNEL)) == NULL)
+		return -ENOMEM;
+		
+	memset(bpq, 0, sizeof(struct bpqdev));
+	
+	bpq->ethdev = dev;
+
+	bpq->ethname[sizeof(bpq->ethname)-1] = '\0';
+	strncpy(bpq->ethname, dev->name, sizeof(bpq->ethname)-1);
+
+	memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
+	memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));
+
+	dev = &bpq->axdev;
+	buf = (unsigned char *)kmalloc(14, GFP_KERNEL);
+
+	for (k = 0; k < MAXBPQDEV; k++) {
+		struct device *odev;
+
+		sprintf(buf, "bpq%d", k);
+
+		if ((odev = dev_get(buf)) == NULL || bpq_check_devices(odev))
+			break;
+	}
+
+	if (k == MAXBPQDEV) {
+		kfree(bpq);
+		return -ENODEV;
+	}
+	
+	dev->priv = (void *)bpq;	/* pointer back */
+	dev->name = buf;
+	dev->init = bpq_dev_init;
+
+	if (register_netdev(dev) != 0) {
+		kfree(bpq);
+                return -EIO;
+        }
+
+	for (k=0; k < DEV_NUMBUFFS; k++)
+		skb_queue_head_init(&dev->buffs[k]);
+
+	dev->hard_start_xmit = bpq_xmit;
+	dev->hard_header     = ax25_encapsulate;
+	dev->rebuild_header  = bpq_rebuild_header;
+	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;
+
+	memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN);
+	memcpy(dev->dev_addr,  ax25_defaddr, AX25_ADDR_LEN);
+
+	/* preset with reasonable values */
+
+#if CONFIG_INET
+	dev->flags      = 0;
+	dev->family     = AF_INET;
+	dev->pa_addr    = 0;
+	dev->pa_brdaddr = 0;
+	dev->pa_mask    = 0;
+	dev->pa_alen    = 4;
+#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;
+	
+	cli();
+
+	if (bpq_devices == NULL) {
+		bpq_devices = bpq;
+	} else {
+		for (bpq2 = bpq_devices; bpq2->next != NULL; bpq2 = bpq2->next);
+		bpq2->next = bpq;
+	}
+	
+	sti();
+
+	return 0;
+}
+
+
+/*
+ *	Handle device status changes.
+ */
+static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr)
+{
+	struct device *dev = (struct device *)ptr;
+	
+	if (!dev_is_ethdev(dev))
+		return NOTIFY_DONE;
+
+	bpq_check_devices(NULL);
+
+	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;
+
+		default:
+			break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+
+/* ------------------------------------------------------------------------ */
+
+/*
+ * Initialize driver. To be called from af_ax25 if not compiled as a
+ * module
+ */
+int bpq_init(void)
+{
+	struct device *dev;
+
+	bpq_packet_type.type  = htons(ETH_P_BPQ);
+	dev_add_pack(&bpq_packet_type);
+
+	register_netdevice_notifier(&bpq_dev_notifier);
+
+	printk(KERN_INFO "AX.25 ethernet driver version 0.01\n");
+
+#ifdef CONFIG_PROC_FS
+	proc_net_register(&(struct proc_dir_entry) {
+		PROC_NET_AX25_BPQETHER, 8, "bpqether",
+		S_IFREG | S_IRUGO, 1, 0, 0,
+		0, &proc_net_inode_operations,
+		bpq_get_info
+	});
+#endif
+
+	for (dev = dev_base; dev != NULL; dev = dev->next) {
+		if (dev_is_ethdev(dev))
+			bpq_new_device(dev);
+	}
+
+	return 0;
+}
+
+#ifdef MODULE
+int init_module(void)
+{
+	register_symtab(NULL);
+
+	return bpq_init();
+}
+
+void cleanup_module(void)
+{
+	struct bpqdev *bpq;
+
+	dev_remove_pack(&bpq_packet_type);
+
+	unregister_netdevice_notifier(&bpq_dev_notifier);
+
+#ifdef CONFIG_PROC_FS
+	proc_net_unregister(PROC_NET_AX25_BPQETHER);
+#endif	
+
+	for (bpq = bpq_devices; bpq != NULL; bpq = bpq->next)
+		unregister_netdev(&bpq->axdev);
+}
+#endif
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