patch-2.1.15 linux/drivers/net/new_tunnel.c

• Lines: 435
• Date: Thu Jan 1 02:00:00 1970
• Orig file: v2.1.14/linux/drivers/net/new_tunnel.c
• Orig date: Fri Jul 19 08:24:05 1996

diff -u --recursive --new-file v2.1.14/linux/drivers/net/new_tunnel.c linux/drivers/net/new_tunnel.c
@@ -1,434 +0,0 @@
-/* tunnel.c: an IP tunnel driver
-
-	The purpose of this driver is to provide an IP tunnel through
-	which you can tunnel network traffic transparently across subnets.
-
-	This was written by looking at Nick Holloway's dummy driver
-	Thanks for the great code!
-
-		-Sam Lantinga	(slouken@cs.ucdavis.edu)  02/01/95
-		
-	Minor tweaks:
-		Cleaned up the code a little and added some pre-1.3.0 tweaks.
-		dev->hard_header/hard_header_len changed to use no headers.
-		Comments/bracketing tweaked.
-		Made the tunnels use dev->name not tunnel: when error reporting.
-		Added tx_dropped stat
-		
-		-Alan Cox	(Alan.Cox@linux.org) 21 March 95
-
-	Reworked:
-		Changed to tunnel to destination gateway in addition to the
-			tunnel's pointopoint address
-		Almost completely rewritten
-		Note:  There is currently no firewall or ICMP handling done.
-
-		-Sam Lantinga	(slouken@cs.ucdavis.edu) 02/13/96
-		
-	Note:
-		The old driver is in tunnel.c if you have funnies with the
-		new one.
-*/
-
-/* Things I wish I had known when writing the tunnel driver:
-
-	When the tunnel_xmit() function is called, the skb contains the
-	packet to be sent (plus a great deal of extra info), and dev
-	contains the tunnel device that _we_ are.
-
-	When we are passed a packet, we are expected to fill in the
-	source address with our source IP address.
-
-	What is the proper way to allocate, copy and free a buffer?
-	After you allocate it, it is a "0 length" chunk of memory
-	starting at zero.  If you want to add headers to the buffer
-	later, you'll have to call "skb_reserve(skb, amount)" with
-	the amount of memory you want reserved.  Then, you call
-	"skb_put(skb, amount)" with the amount of space you want in
-	the buffer.  skb_put() returns a pointer to the top (#0) of
-	that buffer.  skb->len is set to the amount of space you have
-	"allocated" with skb_put().  You can then write up to skb->len
-	bytes to that buffer.  If you need more, you can call skb_put()
-	again with the additional amount of space you need.  You can
-	find out how much more space you can allocate by calling 
-	"skb_tailroom(skb)".
-	Now, to add header space, call "skb_push(skb, header_len)".
-	This creates space at the beginning of the buffer and returns
-	a pointer to this new space.  If later you need to strip a
-	header from a buffer, call "skb_pull(skb, header_len)".
-	skb_headroom() will return how much space is left at the top
-	of the buffer (before the main data).  Remember, this headroom
-	space must be reserved before the skb_put() function is called.
-*/
-
-#include <linux/module.h>
-#include <linux/config.h>	/* for CONFIG_IP_FORWARD */
-
-/* Only two headers!! :-) */
-#include <net/ip.h>
-#include <linux/if_arp.h>
-
-
-/*#define TUNNEL_DEBUG*/
-
-/* 
- *	Our header is a simple IP packet with no options
- */
- 
-#define tunnel_hlen	sizeof(struct iphdr)
-
-/*
- *	Okay, this needs to be high enough that we can fit a "standard"
- *	ethernet header and an IP tunnel header into the outgoing packet.
- *	[36 bytes]
- */
- 
-#define TUNL_HLEN	(((ETH_HLEN+15)&~15)+tunnel_hlen)
-
-
-static int tunnel_open(struct device *dev)
-{
-	MOD_INC_USE_COUNT;
-	return 0;
-}
-
-static int tunnel_close(struct device *dev)
-{
-	MOD_DEC_USE_COUNT;
-	return 0;
-}
-
-#ifdef TUNNEL_DEBUG
-void print_ip(struct iphdr *ip)
-{
-	unsigned char *ipaddr;
-
-	printk("IP packet:\n");
-	printk("--- header len = %d\n", ip->ihl*4);
-	printk("--- ip version: %d\n", ip->version);
-	printk("--- ip protocol: %d\n", ip->protocol);
-	ipaddr=(unsigned char *)&ip->saddr;
-	printk("--- source address: %u.%u.%u.%u\n", 
-			*ipaddr, *(ipaddr+1), *(ipaddr+2), *(ipaddr+3));
-	ipaddr=(unsigned char *)&ip->daddr;
-	printk("--- destination address: %u.%u.%u.%u\n", 
-			*ipaddr, *(ipaddr+1), *(ipaddr+2), *(ipaddr+3));
-	printk("--- total packet len: %d\n", ntohs(ip->tot_len));
-}
-#endif
-
-/*
- *	This function assumes it is being called from dev_queue_xmit()
- *	and that skb is filled properly by that function.
- */
-
-static int tunnel_xmit(struct sk_buff *skb, struct device *dev)
-{
-	struct enet_statistics *stats;		/* This device's statistics */
-	struct rtable *rt;     			/* Route to the other host */
-	struct device *tdev;			/* Device to other host */
-	struct iphdr  *iph;			/* Our new IP header */
-	__u32          target;			/* The other host's IP address */
-	int      max_headroom;			/* The extra header space needed */
-
-	/*
-	 *	Return if there is nothing to do.  (Does this ever happen?)
-	 */
-	if (skb == NULL || dev == NULL) {
-#ifdef TUNNEL_DEBUG
-		printk ( KERN_INFO "tunnel: Nothing to do!\n" );
-#endif
-		return 0;
-	}
-
-	/* 
-	 *	Make sure we are not busy (check lock variable) 
-	 */
-	 
-	stats = (struct enet_statistics *)dev->priv;
-	cli();
-	if (dev->tbusy != 0) 
-	{
-		sti();
-		stats->tx_errors++;
-		return(1);
-	}
-	dev->tbusy = 1;
-	sti();
-  
-	/*printk("-");*/
-	/*
-	 *  First things first.  Look up the destination address in the 
-	 *  routing tables
-	 */
-	iph = (struct iphdr *) skb->data;
-	if ((rt = ip_rt_route(iph->daddr, 0)) == NULL)
-	{ 
-		/* No route to host */
-		/* Where did the packet come from? */
-		/*icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, 0, dev);*/
-		printk ( KERN_INFO "%s: Packet with no route!\n", dev->name);
-		dev->tbusy=0;
-		stats->tx_errors++;
-		dev_kfree_skb(skb, FREE_WRITE);
-		return 0;
-	}
-
-	/*
-	 * Get the target address (other end of IP tunnel)
-	 */
-	if (rt->rt_flags & RTF_GATEWAY)
-		target = rt->rt_gateway;
-	else
-		target = dev->pa_dstaddr;
-
-	if ( ! target )
-	{	/* No gateway to tunnel through? */
-		/* Where did the packet come from? */
-		/*icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, 0, dev);*/
-		printk ( KERN_INFO "%s: Packet with no target gateway!\n", dev->name);
-		ip_rt_put(rt);
-		dev->tbusy=0;
-		stats->tx_errors++;
-		dev_kfree_skb(skb, FREE_WRITE);
-		return 0;
-	}
-	ip_rt_put(rt);
-
-	if ((rt = ip_rt_route(target, 0)) == NULL)
-	{ 
-		/* No route to host */
-		/* Where did the packet come from? */
-		/*icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, 0, dev);*/
-		printk ( KERN_INFO "%s: Can't reach target gateway!\n", dev->name);
-		dev->tbusy=0;
-		stats->tx_errors++;
-		dev_kfree_skb(skb, FREE_WRITE);
-		return 0;
-	}
-	tdev = rt->rt_dev;
-
-	if (tdev == dev)
-	{ 
-		/* Tunnel to ourselves?  -- I don't think so. */
-		printk ( KERN_INFO "%s: Packet targetted at myself!\n" , dev->name);
-		ip_rt_put(rt);
-		dev->tbusy=0;
-		stats->tx_errors++;
-		dev_kfree_skb(skb, FREE_WRITE);
-		return 0;
-	}
-
-#ifdef TUNNEL_DEBUG
-	printk("Old IP Header....\n");
-	print_ip(iph);
-#endif
-
-	/*
-	 * Okay, now see if we can stuff it in the buffer as-is.
-	 */
-	max_headroom = (((tdev->hard_header_len+15)&~15)+tunnel_hlen);
-#ifdef TUNNEL_DEBUG
-printk("Room left at head: %d\n", skb_headroom(skb));
-printk("Room left at tail: %d\n", skb_tailroom(skb));
-printk("Required room: %d, Tunnel hlen: %d\n", max_headroom, TUNL_HLEN);
-#endif
-	if (skb_headroom(skb) >= max_headroom && skb->free) {
-		skb->h.iph = (struct iphdr *) skb_push(skb, tunnel_hlen);
-		skb_device_unlock(skb);
-	} else {
-		struct sk_buff *new_skb;
-
-		if ( !(new_skb = dev_alloc_skb(skb->len+max_headroom)) ) 
-		{
-			printk( KERN_INFO "%s: Out of memory, dropped packet\n",
-				dev->name);
-			ip_rt_put(rt);
-  			dev->tbusy = 0;
-  			stats->tx_dropped++;
-			dev_kfree_skb(skb, FREE_WRITE);
-			return 0;
-		}
-		new_skb->free = 1;
-
-		/*
-		 * Reserve space for our header and the lower device header
-		 */
-		skb_reserve(new_skb, max_headroom);
-
-		/*
-		 * Copy the old packet to the new buffer.
-		 * Note that new_skb->h.iph will be our (tunnel driver's) header
-		 * and new_skb->ip_hdr is the IP header of the old packet.
-		 */
-		new_skb->ip_hdr = (struct iphdr *) skb_put(new_skb, skb->len);
-		new_skb->dev = skb->dev;
-		memcpy(new_skb->ip_hdr, skb->data, skb->len);
-		memset(new_skb->proto_priv, 0, sizeof(skb->proto_priv));
-
-		/* Tack on our header */
-		new_skb->h.iph = (struct iphdr *) skb_push(new_skb, tunnel_hlen);
-
-		/* Free the old packet, we no longer need it */
-		dev_kfree_skb(skb, FREE_WRITE);
-		skb = new_skb;
-	}
-
-	/*
-	 *	Push down and install the IPIP header.
-	 */
-	 
-	iph 			=	skb->h.iph;
-	iph->version		= 	4;
-	iph->tos		=	skb->ip_hdr->tos;
-	iph->ttl		=	skb->ip_hdr->ttl;
-	iph->frag_off		=	0;
-	iph->daddr		=	target;
-	iph->saddr		=	tdev->pa_addr;
-	iph->protocol		=	IPPROTO_IPIP;
-	iph->ihl		=	5;
-	iph->tot_len		=	htons(skb->len);
-	iph->id			=	htons(ip_id_count++);	/* Race condition here? */
-	ip_send_check(iph);
-	skb->ip_hdr 		=	skb->h.iph;
-	skb->protocol		=	htons(ETH_P_IP);
-#ifdef TUNNEL_DEBUG
-	printk("New IP Header....\n");
-	print_ip(iph);
-#endif
-
-	/*
-	 *	Send the packet on its way!
-	 *	Note that dev_queue_xmit() will eventually free the skb.
-	 *	If ip_forward() made a copy, it will return 1 so we can free.
-	 */
-
-#ifdef CONFIG_IP_FORWARD
-	if (ip_forward(skb, dev, IPFWD_NOTTLDEC, target))
-#endif
-		kfree_skb(skb, FREE_WRITE);
-
-	/*
-	 *	Clean up:  We're done with the route and the packet
-	 */
-	 
-	ip_rt_put(rt);
- 
-#ifdef TUNNEL_DEBUG
-	printk("Packet sent through tunnel interface!\n");
-#endif
-/*printk(">");*/
-	/* Record statistics and return */
-	stats->tx_packets++;
-	dev->tbusy=0;
-	return 0;
-}
-
-static struct enet_statistics *tunnel_get_stats(struct device *dev)
-{
-	return((struct enet_statistics*) dev->priv);
-}
-
-/*
- *	Called when a new tunnel device is initialized.
- *	The new tunnel device structure is passed to us.
- */
- 
-int tunnel_init(struct device *dev)
-{
-	int i;
-
-	/* Oh, just say we're here, in case anyone cares */
-	static int tun_msg=0;
-	if(!tun_msg)
-	{
-		printk ( KERN_INFO "tunnel: version v0.2b2\n" );
-		tun_msg=1;
-	}
-
-	/* Add our tunnel functions to the device */
-	dev->open		= tunnel_open;
-	dev->stop		= tunnel_close;
-	dev->hard_start_xmit	= tunnel_xmit;
-	dev->get_stats		= tunnel_get_stats;
-	dev->priv = kmalloc(sizeof(struct enet_statistics), GFP_KERNEL);
-	if (dev->priv == NULL)
-		return -ENOMEM;
-	memset(dev->priv, 0, sizeof(struct enet_statistics));
-
-	/* Initialize the tunnel device structure */
-	for (i = 0; i < DEV_NUMBUFFS; i++)
-		skb_queue_head_init(&dev->buffs[i]);
-
-	dev->hard_header	= NULL;
-	dev->rebuild_header 	= NULL;
-	dev->set_mac_address 	= NULL;
-	dev->header_cache_bind 	= NULL;
-	dev->header_cache_update= NULL;
-
-	dev->type				= ARPHRD_TUNNEL;
-	dev->hard_header_len 	= TUNL_HLEN;
-	dev->mtu		= 1500-tunnel_hlen; 	/* eth_mtu */
-	dev->addr_len		= 0;		/* Is this only for ARP? */
-	dev->tx_queue_len	= 2;		/* Small queue */
-	memset(dev->broadcast,0xFF, ETH_ALEN);
-
-	/* New-style flags. */
-	dev->flags		= IFF_NOARP;	/* Don't use ARP on this device */
-						/* No broadcasting through a tunnel */
-	dev->family		= AF_INET;
-	dev->pa_addr		= 0;
-	dev->pa_brdaddr 	= 0;
-	dev->pa_mask		= 0;
-	dev->pa_alen		= 4;
-
-	/* We're done.  Have I forgotten anything? */
-	return 0;
-}
-
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-/*  Module specific interface                                      */
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-#ifdef MODULE
-
-static int tunnel_probe(struct device *dev)
-{
-	tunnel_init(dev);
-	return 0;
-}
-
-static struct device dev_tunnel = 
-{
-	"tunl0\0   ", 
-	0, 0, 0, 0,
- 	0x0, 0,
- 	0, 0, 0, NULL, tunnel_probe 
- };
-
-int init_module(void)
-{
-	/* Find a name for this unit */
-	int ct= 1;
-	
-	while(dev_get(dev_tunnel.name)!=NULL && ct<100)
-	{
-		sprintf(dev_tunnel.name,"tunl%d",ct);
-		ct++;
-	}
-	
-#ifdef TUNNEL_DEBUG
-	printk("tunnel: registering device %s\n", dev_tunnel.name);
-#endif
-	if (register_netdev(&dev_tunnel) != 0)
-		return -EIO;
-	return 0;
-}
-
-void cleanup_module(void)
-{
-	unregister_netdev(&dev_tunnel);
-	kfree_s(dev_tunnel.priv,sizeof(struct enet_statistics));
-	dev_tunnel.priv=NULL;
-}
-#endif /* MODULE */
-