| /* | 
 |  *	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/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 <asm/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_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); | 
 |  | 
 | static const struct net_device_ops ipddp_netdev_ops = { | 
 | 	.ndo_start_xmit		= ipddp_xmit, | 
 | 	.ndo_do_ioctl   	= ipddp_ioctl, | 
 | 	.ndo_change_mtu		= eth_change_mtu, | 
 | 	.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); | 
 |  | 
 | 	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; | 
 | 	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) | 
 | { | 
 | 	__be32 paddr = skb_rtable(skb)->rt_gateway; | 
 |         struct ddpehdr *ddp; | 
 |         struct ipddp_route *rt; | 
 |         struct atalk_addr *our_addr; | 
 |  | 
 | 	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 = kmalloc(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_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) | 
 | { | 
 |         struct ipddp_route __user *rt = ifr->ifr_data; | 
 |         struct ipddp_route rcp, rcp2, *rp; | 
 |  | 
 |         if(!capable(CAP_NET_ADMIN)) | 
 |                 return -EPERM; | 
 |  | 
 | 	if(copy_from_user(&rcp, rt, 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) | 
 | 				memcpy(&rcp2, rp, sizeof(rcp2)); | 
 | 			spin_unlock_bh(&ipddp_route_lock); | 
 |  | 
 | 			if (rp) { | 
 | 				if (copy_to_user(rt, &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(); | 
 |         if (IS_ERR(dev_ipddp)) | 
 |                 return PTR_ERR(dev_ipddp); | 
 | 	return 0; | 
 | } | 
 |  | 
 | 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); |