/* * 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 * - DDP-IP Decap by: Jay Schulist * * 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 * - 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 * * 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 #include #include #include #include #include #include #include #include #include #include #include "ipddp.h" /* Our stuff */ static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson \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 \n", dev->name); if(ipddp_mode == IPDDP_DECAP) printk("%s: Appletalk-IP Decap. mode by Jay Schulist \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);