/*
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* ipddp.c: IP to Appletalk-IP Encapsulation driver for Linux
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* Appletalk-IP to IP Decapsulation driver for Linux
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*
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* Authors:
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* - DDP-IP Encap by: Bradford W. Johnson <johns393@maroon.tc.umn.edu>
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* - DDP-IP Decap by: Jay Schulist <jschlst@samba.org>
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*
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* Derived from:
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* - Almost all code already existed in net/appletalk/ddp.c I just
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* moved/reorginized it into a driver file. Original IP-over-DDP code
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* was done by Bradford W. Johnson <johns393@maroon.tc.umn.edu>
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* - skeleton.c: A network driver outline for linux.
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* Written 1993-94 by Donald Becker.
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* - dummy.c: A dummy net driver. By Nick Holloway.
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* - MacGate: A user space Daemon for Appletalk-IP Decap for
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* Linux by Jay Schulist <jschlst@samba.org>
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*
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* Copyright 1993 United States Government as represented by the
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* Director, National Security Agency.
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*
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* This software may be used and distributed according to the terms
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* of the GNU General Public License, incorporated herein by reference.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/ip.h>
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#include <linux/atalk.h>
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#include <linux/if_arp.h>
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#include <linux/slab.h>
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#include <net/route.h>
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#include <linux/uaccess.h>
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#include "ipddp.h" /* Our stuff */
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static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n";
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static struct ipddp_route *ipddp_route_list;
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static DEFINE_SPINLOCK(ipddp_route_lock);
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#ifdef CONFIG_IPDDP_ENCAP
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static int ipddp_mode = IPDDP_ENCAP;
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#else
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static int ipddp_mode = IPDDP_DECAP;
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#endif
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/* Index to functions, as function prototypes. */
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static netdev_tx_t ipddp_xmit(struct sk_buff *skb,
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struct net_device *dev);
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static int ipddp_create(struct ipddp_route *new_rt);
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static int ipddp_delete(struct ipddp_route *rt);
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static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt);
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static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
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static const struct net_device_ops ipddp_netdev_ops = {
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.ndo_start_xmit = ipddp_xmit,
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.ndo_do_ioctl = ipddp_ioctl,
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.ndo_set_mac_address = eth_mac_addr,
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.ndo_validate_addr = eth_validate_addr,
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};
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static struct net_device * __init ipddp_init(void)
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{
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static unsigned version_printed;
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struct net_device *dev;
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int err;
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dev = alloc_etherdev(0);
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if (!dev)
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return ERR_PTR(-ENOMEM);
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netif_keep_dst(dev);
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strcpy(dev->name, "ipddp%d");
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if (version_printed++ == 0)
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printk(version);
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/* Initialize the device structure. */
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dev->netdev_ops = &ipddp_netdev_ops;
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dev->type = ARPHRD_IPDDP; /* IP over DDP tunnel */
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dev->mtu = 585;
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dev->flags |= IFF_NOARP;
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/*
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* The worst case header we will need is currently a
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* ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1)
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* We send over SNAP so that takes another 8 bytes.
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*/
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dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1;
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err = register_netdev(dev);
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if (err) {
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free_netdev(dev);
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return ERR_PTR(err);
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}
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/* Let the user now what mode we are in */
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if(ipddp_mode == IPDDP_ENCAP)
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printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n",
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dev->name);
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if(ipddp_mode == IPDDP_DECAP)
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printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n",
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dev->name);
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return dev;
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}
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/*
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* Transmit LLAP/ELAP frame using aarp_send_ddp.
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*/
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static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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__be32 paddr = skb_rtable(skb)->rt_gateway;
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struct ddpehdr *ddp;
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struct ipddp_route *rt;
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struct atalk_addr *our_addr;
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spin_lock(&ipddp_route_lock);
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/*
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* Find appropriate route to use, based only on IP number.
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*/
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for(rt = ipddp_route_list; rt != NULL; rt = rt->next)
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{
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if(rt->ip == paddr)
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break;
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}
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if(rt == NULL) {
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spin_unlock(&ipddp_route_lock);
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return NETDEV_TX_OK;
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}
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our_addr = atalk_find_dev_addr(rt->dev);
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if(ipddp_mode == IPDDP_DECAP)
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/*
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* Pull off the excess room that should not be there.
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* This is due to a hard-header problem. This is the
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* quick fix for now though, till it breaks.
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*/
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skb_pull(skb, 35-(sizeof(struct ddpehdr)+1));
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/* Create the Extended DDP header */
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ddp = (struct ddpehdr *)skb->data;
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ddp->deh_len_hops = htons(skb->len + (1<<10));
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ddp->deh_sum = 0;
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/*
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* For Localtalk we need aarp_send_ddp to strip the
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* long DDP header and place a shot DDP header on it.
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*/
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if(rt->dev->type == ARPHRD_LOCALTLK)
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{
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ddp->deh_dnet = 0; /* FIXME more hops?? */
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ddp->deh_snet = 0;
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}
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else
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{
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ddp->deh_dnet = rt->at.s_net; /* FIXME more hops?? */
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ddp->deh_snet = our_addr->s_net;
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}
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ddp->deh_dnode = rt->at.s_node;
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ddp->deh_snode = our_addr->s_node;
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ddp->deh_dport = 72;
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ddp->deh_sport = 72;
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*((__u8 *)(ddp+1)) = 22; /* ddp type = IP */
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skb->protocol = htons(ETH_P_ATALK); /* Protocol has changed */
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dev->stats.tx_packets++;
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dev->stats.tx_bytes += skb->len;
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aarp_send_ddp(rt->dev, skb, &rt->at, NULL);
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spin_unlock(&ipddp_route_lock);
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return NETDEV_TX_OK;
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}
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/*
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* Create a routing entry. We first verify that the
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* record does not already exist. If it does we return -EEXIST
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*/
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static int ipddp_create(struct ipddp_route *new_rt)
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{
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struct ipddp_route *rt = kzalloc(sizeof(*rt), GFP_KERNEL);
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if (rt == NULL)
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return -ENOMEM;
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rt->ip = new_rt->ip;
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rt->at = new_rt->at;
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rt->next = NULL;
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if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) {
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kfree(rt);
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return -ENETUNREACH;
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}
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spin_lock_bh(&ipddp_route_lock);
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if (__ipddp_find_route(rt)) {
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spin_unlock_bh(&ipddp_route_lock);
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kfree(rt);
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return -EEXIST;
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}
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rt->next = ipddp_route_list;
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ipddp_route_list = rt;
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spin_unlock_bh(&ipddp_route_lock);
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return 0;
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}
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/*
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* Delete a route, we only delete a FULL match.
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* If route does not exist we return -ENOENT.
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*/
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static int ipddp_delete(struct ipddp_route *rt)
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{
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struct ipddp_route **r = &ipddp_route_list;
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struct ipddp_route *tmp;
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spin_lock_bh(&ipddp_route_lock);
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while((tmp = *r) != NULL)
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{
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if(tmp->ip == rt->ip &&
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tmp->at.s_net == rt->at.s_net &&
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tmp->at.s_node == rt->at.s_node)
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{
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*r = tmp->next;
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spin_unlock_bh(&ipddp_route_lock);
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kfree(tmp);
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return 0;
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}
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r = &tmp->next;
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}
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spin_unlock_bh(&ipddp_route_lock);
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return -ENOENT;
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}
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/*
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* Find a routing entry, we only return a FULL match
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*/
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static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt)
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{
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struct ipddp_route *f;
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for(f = ipddp_route_list; f != NULL; f = f->next)
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{
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if(f->ip == rt->ip &&
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f->at.s_net == rt->at.s_net &&
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f->at.s_node == rt->at.s_node)
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return f;
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}
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return NULL;
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}
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static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
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{
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struct ipddp_route __user *rt = ifr->ifr_data;
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struct ipddp_route rcp, rcp2, *rp;
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if(!capable(CAP_NET_ADMIN))
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return -EPERM;
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if(copy_from_user(&rcp, rt, sizeof(rcp)))
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return -EFAULT;
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switch(cmd)
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{
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case SIOCADDIPDDPRT:
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return ipddp_create(&rcp);
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case SIOCFINDIPDDPRT:
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spin_lock_bh(&ipddp_route_lock);
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rp = __ipddp_find_route(&rcp);
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if (rp) {
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memset(&rcp2, 0, sizeof(rcp2));
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rcp2.ip = rp->ip;
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rcp2.at = rp->at;
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rcp2.flags = rp->flags;
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}
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spin_unlock_bh(&ipddp_route_lock);
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if (rp) {
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if (copy_to_user(rt, &rcp2,
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sizeof(struct ipddp_route)))
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return -EFAULT;
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return 0;
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} else
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return -ENOENT;
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case SIOCDELIPDDPRT:
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return ipddp_delete(&rcp);
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default:
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return -EINVAL;
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}
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}
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static struct net_device *dev_ipddp;
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MODULE_LICENSE("GPL");
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module_param(ipddp_mode, int, 0);
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static int __init ipddp_init_module(void)
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{
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dev_ipddp = ipddp_init();
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return PTR_ERR_OR_ZERO(dev_ipddp);
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}
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static void __exit ipddp_cleanup_module(void)
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{
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struct ipddp_route *p;
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unregister_netdev(dev_ipddp);
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free_netdev(dev_ipddp);
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while (ipddp_route_list) {
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p = ipddp_route_list->next;
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kfree(ipddp_route_list);
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ipddp_route_list = p;
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}
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}
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module_init(ipddp_init_module);
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module_exit(ipddp_cleanup_module);
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