/*
* 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 <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;
#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 int ipddp_xmit(struct sk_buff *skb, struct net_device *dev);
static struct net_device_stats *ipddp_get_stats(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 struct net_device * __init ipddp_init(void)
{
static unsigned version_printed;
struct net_device *dev;
int err;
dev = alloc_etherdev(sizeof(struct net_device_stats));
if (!dev)
return ERR_PTR(-ENOMEM);
strcpy(dev->name, "ipddp%d");
if (version_printed++ == 0)
printk(version);
/* Initalize the device structure. */
dev->hard_start_xmit = ipddp_xmit;
dev->get_stats = ipddp_get_stats;
dev->do_ioctl = ipddp_ioctl;
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;
}
/*
* Get the current statistics. This may be called with the card open or closed.
*/
static struct net_device_stats *ipddp_get_stats(struct net_device *dev)
{
return dev->priv;
}
/*
* Transmit LLAP/ELAP frame using aarp_send_ddp.
*/
static int ipddp_xmit(struct sk_buff *skb, struct net_device *dev)
{
u32 paddr = ((struct rtable*)skb->dst)->rt_gateway;
struct ddpehdr *ddp;
struct ipddp_route *rt;
struct atalk_addr *our_addr;
/*
* 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)
return 0;
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 */
((struct net_device_stats *) dev->priv)->tx_packets++;
((struct net_device_stats *) dev->priv)->tx_bytes+=skb->len;
if(aarp_send_ddp(rt->dev, skb, &rt->at, NULL) < 0)
dev_kfree_skb(skb);
return 0;
}
/*
* 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;
}
if (ipddp_find_route(rt)) {
kfree(rt);
return -EEXIST;
}
rt->next = ipddp_route_list;
ipddp_route_list = rt;
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;
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;
kfree(tmp);
return 0;
}
r = &tmp->next;
}
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;
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:
if(copy_to_user(rt, ipddp_find_route(&rcp), sizeof(struct ipddp_route)))
return -EFAULT;
return 0;
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);
