drivers/net/appletalk/ipddp.c - linux - Git at Google

 /*
  *	ipddp.c: IP to Appletalk-IP Encapsulation driver for Linux
  *		 Appletalk-IP to IP Decapsulation driver for Linux
  *
  *	Authors:
  *      - DDP-IP Encap by: Bradford W. Johnson <johns393@maroon.tc.umn.edu>
  *	- DDP-IP Decap by: Jay Schulist <jschlst@samba.org>
  *
  *	Derived from:
  *	- Almost all code already existed in net/appletalk/ddp.c I just
  *	  moved/reorginized it into a driver file. Original IP-over-DDP code
  *	  was done by Bradford W. Johnson <johns393@maroon.tc.umn.edu>
  *      - skeleton.c: A network driver outline for linux.
  *        Written 1993-94 by Donald Becker.
  *	- dummy.c: A dummy net driver. By Nick Holloway.
  *	- MacGate: A user space Daemon for Appletalk-IP Decap for
  *	  Linux by Jay Schulist <jschlst@samba.org>
  *
  *      Copyright 1993 United States Government as represented by the
  *      Director, National Security Agency.
  *
  *      This software may be used and distributed according to the terms
  *      of the GNU General Public License, incorporated herein by reference.
  */

 #include <linux/compat.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/ip.h>
 #include <linux/atalk.h>
 #include <linux/if_arp.h>
 #include <linux/slab.h>
 #include <net/route.h>
 #include <linux/uaccess.h>

 #include "ipddp.h"		/* Our stuff */

 static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n";

 static struct ipddp_route *ipddp_route_list;
 static DEFINE_SPINLOCK(ipddp_route_lock);

 #ifdef CONFIG_IPDDP_ENCAP
 static int ipddp_mode = IPDDP_ENCAP;
 #else
 static int ipddp_mode = IPDDP_DECAP;
 #endif

 /* Index to functions, as function prototypes. */
 static netdev_tx_t ipddp_xmit(struct sk_buff *skb,
 				    struct net_device *dev);
 static int ipddp_create(struct ipddp_route *new_rt);
 static int ipddp_delete(struct ipddp_route *rt);
 static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt);
 static int ipddp_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 				void __user *data, int cmd);

 static const struct net_device_ops ipddp_netdev_ops = {
 	.ndo_start_xmit		= ipddp_xmit,
 	.ndo_siocdevprivate	= ipddp_siocdevprivate,
 	.ndo_set_mac_address 	= eth_mac_addr,
 	.ndo_validate_addr	= eth_validate_addr,
 };

 static struct net_device * __init ipddp_init(void)
 {
 	static unsigned version_printed;
 	struct net_device *dev;
 	int err;

 	dev = alloc_etherdev(0);
 	if (!dev)
 		return ERR_PTR(-ENOMEM);

 	netif_keep_dst(dev);
 	strcpy(dev->name, "ipddp%d");

 	if (version_printed++ == 0)
                 printk(version);

 	/* Initialize the device structure. */
 	dev->netdev_ops = &ipddp_netdev_ops;

         dev->type = ARPHRD_IPDDP;       	/* IP over DDP tunnel */
         dev->mtu = 585;
         dev->flags |= IFF_NOARP;

         /*
          *      The worst case header we will need is currently a
          *      ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1)
          *      We send over SNAP so that takes another 8 bytes.
          */
         dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1;

 	err = register_netdev(dev);
 	if (err) {
 		free_netdev(dev);
 		return ERR_PTR(err);
 	}

 	/* Let the user now what mode we are in */
 	if(ipddp_mode == IPDDP_ENCAP)
 		printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n",
 			dev->name);
 	if(ipddp_mode == IPDDP_DECAP)
 		printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n",
 			dev->name);

         return dev;
 }


 /*
  * Transmit LLAP/ELAP frame using aarp_send_ddp.
  */
 static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct rtable *rtable = skb_rtable(skb);
         __be32 paddr = 0;
         struct ddpehdr *ddp;
         struct ipddp_route *rt;
         struct atalk_addr *our_addr;

 	if (rtable->rt_gw_family == AF_INET)
 		paddr = rtable->rt_gw4;

 	spin_lock(&ipddp_route_lock);

 	/*
          * Find appropriate route to use, based only on IP number.
          */
         for(rt = ipddp_route_list; rt != NULL; rt = rt->next)
         {
                 if(rt->ip == paddr)
                         break;
         }
         if(rt == NULL) {
 		spin_unlock(&ipddp_route_lock);
                 return NETDEV_TX_OK;
 	}

         our_addr = atalk_find_dev_addr(rt->dev);

 	if(ipddp_mode == IPDDP_DECAP)
 		/*
 		 * Pull off the excess room that should not be there.
 		 * This is due to a hard-header problem. This is the
 		 * quick fix for now though, till it breaks.
 		 */
 		skb_pull(skb, 35-(sizeof(struct ddpehdr)+1));

 	/* Create the Extended DDP header */
 	ddp = (struct ddpehdr *)skb->data;
         ddp->deh_len_hops = htons(skb->len + (1<<10));
         ddp->deh_sum = 0;

 	/*
          * For Localtalk we need aarp_send_ddp to strip the
          * long DDP header and place a shot DDP header on it.
          */
         if(rt->dev->type == ARPHRD_LOCALTLK)
         {
                 ddp->deh_dnet  = 0;   /* FIXME more hops?? */
                 ddp->deh_snet  = 0;
         }
         else
         {
                 ddp->deh_dnet  = rt->at.s_net;   /* FIXME more hops?? */
                 ddp->deh_snet  = our_addr->s_net;
         }
         ddp->deh_dnode = rt->at.s_node;
         ddp->deh_snode = our_addr->s_node;
         ddp->deh_dport = 72;
         ddp->deh_sport = 72;

         *((__u8 *)(ddp+1)) = 22;        	/* ddp type = IP */

         skb->protocol = htons(ETH_P_ATALK);     /* Protocol has changed */

 	dev->stats.tx_packets++;
 	dev->stats.tx_bytes += skb->len;

 	aarp_send_ddp(rt->dev, skb, &rt->at, NULL);

 	spin_unlock(&ipddp_route_lock);

         return NETDEV_TX_OK;
 }

 /*
  * Create a routing entry. We first verify that the
  * record does not already exist. If it does we return -EEXIST
  */
 static int ipddp_create(struct ipddp_route *new_rt)
 {
         struct ipddp_route *rt = kzalloc(sizeof(*rt), GFP_KERNEL);

         if (rt == NULL)
                 return -ENOMEM;

         rt->ip = new_rt->ip;
         rt->at = new_rt->at;
         rt->next = NULL;
         if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) {
 		kfree(rt);
                 return -ENETUNREACH;
         }

 	spin_lock_bh(&ipddp_route_lock);
 	if (__ipddp_find_route(rt)) {
 		spin_unlock_bh(&ipddp_route_lock);
 		kfree(rt);
 		return -EEXIST;
 	}

         rt->next = ipddp_route_list;
         ipddp_route_list = rt;

 	spin_unlock_bh(&ipddp_route_lock);

         return 0;
 }

 /*
  * Delete a route, we only delete a FULL match.
  * If route does not exist we return -ENOENT.
  */
 static int ipddp_delete(struct ipddp_route *rt)
 {
         struct ipddp_route **r = &ipddp_route_list;
         struct ipddp_route *tmp;

 	spin_lock_bh(&ipddp_route_lock);
         while((tmp = *r) != NULL)
         {
                 if(tmp->ip == rt->ip &&
 		   tmp->at.s_net == rt->at.s_net &&
 		   tmp->at.s_node == rt->at.s_node)
                 {
                         *r = tmp->next;
 			spin_unlock_bh(&ipddp_route_lock);
                         kfree(tmp);
                         return 0;
                 }
                 r = &tmp->next;
         }

 	spin_unlock_bh(&ipddp_route_lock);
         return -ENOENT;
 }

 /*
  * Find a routing entry, we only return a FULL match
  */
 static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt)
 {
         struct ipddp_route *f;

         for(f = ipddp_route_list; f != NULL; f = f->next)
         {
                 if(f->ip == rt->ip &&
 		   f->at.s_net == rt->at.s_net &&
 		   f->at.s_node == rt->at.s_node)
                         return f;
         }

         return NULL;
 }

 static int ipddp_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 				void __user *data, int cmd)
 {
         struct ipddp_route rcp, rcp2, *rp;

 	if (in_compat_syscall())
 		return -EOPNOTSUPP;

         if(!capable(CAP_NET_ADMIN))
                 return -EPERM;

 	if (copy_from_user(&rcp, data, sizeof(rcp)))
 		return -EFAULT;

         switch(cmd)
         {
 		case SIOCADDIPDDPRT:
                         return ipddp_create(&rcp);

                 case SIOCFINDIPDDPRT:
 			spin_lock_bh(&ipddp_route_lock);
 			rp = __ipddp_find_route(&rcp);
 			if (rp) {
 				memset(&rcp2, 0, sizeof(rcp2));
 				rcp2.ip    = rp->ip;
 				rcp2.at    = rp->at;
 				rcp2.flags = rp->flags;
 			}
 			spin_unlock_bh(&ipddp_route_lock);

 			if (rp) {
 				if (copy_to_user(data, &rcp2,
 						 sizeof(struct ipddp_route)))
 					return -EFAULT;
 				return 0;
 			} else
 				return -ENOENT;

                 case SIOCDELIPDDPRT:
                         return ipddp_delete(&rcp);

                 default:
                         return -EINVAL;
         }
 }

 static struct net_device *dev_ipddp;

 MODULE_LICENSE("GPL");
 module_param(ipddp_mode, int, 0);

 static int __init ipddp_init_module(void)
 {
 	dev_ipddp = ipddp_init();
 	return PTR_ERR_OR_ZERO(dev_ipddp);
 }

 static void __exit ipddp_cleanup_module(void)
 {
         struct ipddp_route *p;

 	unregister_netdev(dev_ipddp);
         free_netdev(dev_ipddp);

         while (ipddp_route_list) {
                 p = ipddp_route_list->next;
                 kfree(ipddp_route_list);
                 ipddp_route_list = p;
         }
 }

 module_init(ipddp_init_module);
 module_exit(ipddp_cleanup_module);
	/*
	* ipddp.c: IP to Appletalk-IP Encapsulation driver for Linux
	* Appletalk-IP to IP Decapsulation driver for Linux
	*
	* Authors:
	* - DDP-IP Encap by: Bradford W. Johnson <johns393@maroon.tc.umn.edu>
	* - DDP-IP Decap by: Jay Schulist <jschlst@samba.org>
	*
	* Derived from:
	* - Almost all code already existed in net/appletalk/ddp.c I just
	* moved/reorginized it into a driver file. Original IP-over-DDP code
	* was done by Bradford W. Johnson <johns393@maroon.tc.umn.edu>
	* - skeleton.c: A network driver outline for linux.
	* Written 1993-94 by Donald Becker.
	* - dummy.c: A dummy net driver. By Nick Holloway.
	* - MacGate: A user space Daemon for Appletalk-IP Decap for
	* Linux by Jay Schulist <jschlst@samba.org>
	*
	* Copyright 1993 United States Government as represented by the
	* Director, National Security Agency.
	*
	* This software may be used and distributed according to the terms
	* of the GNU General Public License, incorporated herein by reference.
	*/

	#include <linux/compat.h>
	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/ip.h>
	#include <linux/atalk.h>
	#include <linux/if_arp.h>
	#include <linux/slab.h>
	#include <net/route.h>
	#include <linux/uaccess.h>

	#include "ipddp.h" /* Our stuff */

	static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n";

	static struct ipddp_route *ipddp_route_list;
	static DEFINE_SPINLOCK(ipddp_route_lock);

	#ifdef CONFIG_IPDDP_ENCAP
	static int ipddp_mode = IPDDP_ENCAP;
	#else
	static int ipddp_mode = IPDDP_DECAP;
	#endif

	/* Index to functions, as function prototypes. */
	static netdev_tx_t ipddp_xmit(struct sk_buff *skb,
	struct net_device *dev);
	static int ipddp_create(struct ipddp_route *new_rt);
	static int ipddp_delete(struct ipddp_route *rt);
	static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt);
	static int ipddp_siocdevprivate(struct net_device dev, struct ifreq ifr,
	void __user *data, int cmd);

	static const struct net_device_ops ipddp_netdev_ops = {
	.ndo_start_xmit = ipddp_xmit,
	.ndo_siocdevprivate = ipddp_siocdevprivate,
	.ndo_set_mac_address = eth_mac_addr,
	.ndo_validate_addr = eth_validate_addr,
	};

	static struct net_device * __init ipddp_init(void)
	{
	static unsigned version_printed;
	struct net_device *dev;
	int err;

	dev = alloc_etherdev(0);
	if (!dev)
	return ERR_PTR(-ENOMEM);

	netif_keep_dst(dev);
	strcpy(dev->name, "ipddp%d");

	if (version_printed++ == 0)
	printk(version);

	/* Initialize the device structure. */
	dev->netdev_ops = &ipddp_netdev_ops;

	dev->type = ARPHRD_IPDDP; /* IP over DDP tunnel */
	dev->mtu = 585;
	dev->flags \|= IFF_NOARP;

	/*
	* The worst case header we will need is currently a
	* ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1)
	* We send over SNAP so that takes another 8 bytes.
	*/
	dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1;

	err = register_netdev(dev);
	if (err) {
	free_netdev(dev);
	return ERR_PTR(err);
	}

	/* Let the user now what mode we are in */
	if(ipddp_mode == IPDDP_ENCAP)
	printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n",
	dev->name);
	if(ipddp_mode == IPDDP_DECAP)
	printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n",
	dev->name);

	return dev;
	}


	/*
	* Transmit LLAP/ELAP frame using aarp_send_ddp.
	*/
	static netdev_tx_t ipddp_xmit(struct sk_buff skb, struct net_device dev)
	{
	struct rtable *rtable = skb_rtable(skb);
	__be32 paddr = 0;
	struct ddpehdr *ddp;
	struct ipddp_route *rt;
	struct atalk_addr *our_addr;

	if (rtable->rt_gw_family == AF_INET)
	paddr = rtable->rt_gw4;

	spin_lock(&ipddp_route_lock);

	/*
	* Find appropriate route to use, based only on IP number.
	*/
	for(rt = ipddp_route_list; rt != NULL; rt = rt->next)
	{
	if(rt->ip == paddr)
	break;
	}
	if(rt == NULL) {
	spin_unlock(&ipddp_route_lock);
	return NETDEV_TX_OK;
	}

	our_addr = atalk_find_dev_addr(rt->dev);

	if(ipddp_mode == IPDDP_DECAP)
	/*
	* Pull off the excess room that should not be there.
	* This is due to a hard-header problem. This is the
	* quick fix for now though, till it breaks.
	*/
	skb_pull(skb, 35-(sizeof(struct ddpehdr)+1));

	/* Create the Extended DDP header */
	ddp = (struct ddpehdr *)skb->data;
	ddp->deh_len_hops = htons(skb->len + (1<<10));
	ddp->deh_sum = 0;

	/*
	* For Localtalk we need aarp_send_ddp to strip the
	* long DDP header and place a shot DDP header on it.
	*/
	if(rt->dev->type == ARPHRD_LOCALTLK)
	{
	ddp->deh_dnet = 0; /* FIXME more hops?? */
	ddp->deh_snet = 0;
	}
	else
	{
	ddp->deh_dnet = rt->at.s_net; /* FIXME more hops?? */
	ddp->deh_snet = our_addr->s_net;
	}
	ddp->deh_dnode = rt->at.s_node;
	ddp->deh_snode = our_addr->s_node;
	ddp->deh_dport = 72;
	ddp->deh_sport = 72;

	((__u8 )(ddp+1)) = 22; /* ddp type = IP */

	skb->protocol = htons(ETH_P_ATALK); /* Protocol has changed */

	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;

	aarp_send_ddp(rt->dev, skb, &rt->at, NULL);

	spin_unlock(&ipddp_route_lock);

	return NETDEV_TX_OK;
	}

	/*
	* Create a routing entry. We first verify that the
	* record does not already exist. If it does we return -EEXIST
	*/
	static int ipddp_create(struct ipddp_route *new_rt)
	{
	struct ipddp_route rt = kzalloc(sizeof(rt), GFP_KERNEL);

	if (rt == NULL)
	return -ENOMEM;

	rt->ip = new_rt->ip;
	rt->at = new_rt->at;
	rt->next = NULL;
	if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) {
	kfree(rt);
	return -ENETUNREACH;
	}

	spin_lock_bh(&ipddp_route_lock);
	if (__ipddp_find_route(rt)) {
	spin_unlock_bh(&ipddp_route_lock);
	kfree(rt);
	return -EEXIST;
	}

	rt->next = ipddp_route_list;
	ipddp_route_list = rt;

	spin_unlock_bh(&ipddp_route_lock);

	return 0;
	}

	/*
	* Delete a route, we only delete a FULL match.
	* If route does not exist we return -ENOENT.
	*/
	static int ipddp_delete(struct ipddp_route *rt)
	{
	struct ipddp_route **r = &ipddp_route_list;
	struct ipddp_route *tmp;

	spin_lock_bh(&ipddp_route_lock);
	while((tmp = *r) != NULL)
	{
	if(tmp->ip == rt->ip &&
	tmp->at.s_net == rt->at.s_net &&
	tmp->at.s_node == rt->at.s_node)
	{
	*r = tmp->next;
	spin_unlock_bh(&ipddp_route_lock);
	kfree(tmp);
	return 0;
	}
	r = &tmp->next;
	}

	spin_unlock_bh(&ipddp_route_lock);
	return -ENOENT;
	}

	/*
	* Find a routing entry, we only return a FULL match
	*/
	static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt)
	{
	struct ipddp_route *f;

	for(f = ipddp_route_list; f != NULL; f = f->next)
	{
	if(f->ip == rt->ip &&
	f->at.s_net == rt->at.s_net &&
	f->at.s_node == rt->at.s_node)
	return f;
	}

	return NULL;
	}

	static int ipddp_siocdevprivate(struct net_device dev, struct ifreq ifr,
	void __user *data, int cmd)
	{
	struct ipddp_route rcp, rcp2, *rp;

	if (in_compat_syscall())
	return -EOPNOTSUPP;

	if(!capable(CAP_NET_ADMIN))
	return -EPERM;

	if (copy_from_user(&rcp, data, sizeof(rcp)))
	return -EFAULT;

	switch(cmd)
	{
	case SIOCADDIPDDPRT:
	return ipddp_create(&rcp);

	case SIOCFINDIPDDPRT:
	spin_lock_bh(&ipddp_route_lock);
	rp = __ipddp_find_route(&rcp);
	if (rp) {
	memset(&rcp2, 0, sizeof(rcp2));
	rcp2.ip = rp->ip;
	rcp2.at = rp->at;
	rcp2.flags = rp->flags;
	}
	spin_unlock_bh(&ipddp_route_lock);

	if (rp) {
	if (copy_to_user(data, &rcp2,
	sizeof(struct ipddp_route)))
	return -EFAULT;
	return 0;
	} else
	return -ENOENT;

	case SIOCDELIPDDPRT:
	return ipddp_delete(&rcp);

	default:
	return -EINVAL;
	}
	}

	static struct net_device *dev_ipddp;

	MODULE_LICENSE("GPL");
	module_param(ipddp_mode, int, 0);

	static int __init ipddp_init_module(void)
	{
	dev_ipddp = ipddp_init();
	return PTR_ERR_OR_ZERO(dev_ipddp);
	}

	static void __exit ipddp_cleanup_module(void)
	{
	struct ipddp_route *p;

	unregister_netdev(dev_ipddp);
	free_netdev(dev_ipddp);

	while (ipddp_route_list) {
	p = ipddp_route_list->next;
	kfree(ipddp_route_list);
	ipddp_route_list = p;
	}
	}

	module_init(ipddp_init_module);
	module_exit(ipddp_cleanup_module);