/* * 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); SET_MODULE_OWNER(dev); 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);