1/* 2 * ipddp.c: IP to Appletalk-IP Encapsulation driver for Linux 3 * Appletalk-IP to IP Decapsulation driver for Linux 4 * 5 * Authors: 6 * - DDP-IP Encap by: Bradford W. Johnson <johns393@maroon.tc.umn.edu> 7 * - DDP-IP Decap by: Jay Schulist <jschlst@samba.org> 8 * 9 * Derived from: 10 * - Almost all code already existed in net/appletalk/ddp.c I just 11 * moved/reorginized it into a driver file. Original IP-over-DDP code 12 * was done by Bradford W. Johnson <johns393@maroon.tc.umn.edu> 13 * - skeleton.c: A network driver outline for linux. 14 * Written 1993-94 by Donald Becker. 15 * - dummy.c: A dummy net driver. By Nick Holloway. 16 * - MacGate: A user space Daemon for Appletalk-IP Decap for 17 * Linux by Jay Schulist <jschlst@samba.org> 18 * 19 * Copyright 1993 United States Government as represented by the 20 * Director, National Security Agency. 21 * 22 * This software may be used and distributed according to the terms 23 * of the GNU General Public License, incorporated herein by reference. 24 */ 25 26#include <linux/module.h> 27#include <linux/kernel.h> 28#include <linux/init.h> 29#include <linux/netdevice.h> 30#include <linux/etherdevice.h> 31#include <linux/ip.h> 32#include <linux/atalk.h> 33#include <linux/if_arp.h> 34#include <linux/slab.h> 35#include <net/route.h> 36#include <asm/uaccess.h> 37 38#include "ipddp.h" /* Our stuff */ 39 40static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n"; 41 42static struct ipddp_route *ipddp_route_list; 43static DEFINE_SPINLOCK(ipddp_route_lock); 44 45#ifdef CONFIG_IPDDP_ENCAP 46static int ipddp_mode = IPDDP_ENCAP; 47#else 48static int ipddp_mode = IPDDP_DECAP; 49#endif 50 51/* Index to functions, as function prototypes. */ 52static netdev_tx_t ipddp_xmit(struct sk_buff *skb, 53 struct net_device *dev); 54static int ipddp_create(struct ipddp_route *new_rt); 55static int ipddp_delete(struct ipddp_route *rt); 56static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt); 57static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 58 59static const struct net_device_ops ipddp_netdev_ops = { 60 .ndo_start_xmit = ipddp_xmit, 61 .ndo_do_ioctl = ipddp_ioctl, 62 .ndo_change_mtu = eth_change_mtu, 63 .ndo_set_mac_address = eth_mac_addr, 64 .ndo_validate_addr = eth_validate_addr, 65}; 66 67static struct net_device * __init ipddp_init(void) 68{ 69 static unsigned version_printed; 70 struct net_device *dev; 71 int err; 72 73 dev = alloc_etherdev(0); 74 if (!dev) 75 return ERR_PTR(-ENOMEM); 76 77 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 78 strcpy(dev->name, "ipddp%d"); 79 80 if (version_printed++ == 0) 81 printk(version); 82 83 /* Initialize the device structure. */ 84 dev->netdev_ops = &ipddp_netdev_ops; 85 86 dev->type = ARPHRD_IPDDP; /* IP over DDP tunnel */ 87 dev->mtu = 585; 88 dev->flags |= IFF_NOARP; 89 90 /* 91 * The worst case header we will need is currently a 92 * ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1) 93 * We send over SNAP so that takes another 8 bytes. 94 */ 95 dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1; 96 97 err = register_netdev(dev); 98 if (err) { 99 free_netdev(dev); 100 return ERR_PTR(err); 101 } 102 103 /* Let the user now what mode we are in */ 104 if(ipddp_mode == IPDDP_ENCAP) 105 printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n", 106 dev->name); 107 if(ipddp_mode == IPDDP_DECAP) 108 printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n", 109 dev->name); 110 111 return dev; 112} 113 114 115/* 116 * Transmit LLAP/ELAP frame using aarp_send_ddp. 117 */ 118static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev) 119{ 120 __be32 paddr = skb_rtable(skb)->rt_gateway; 121 struct ddpehdr *ddp; 122 struct ipddp_route *rt; 123 struct atalk_addr *our_addr; 124 125 spin_lock(&ipddp_route_lock); 126 127 /* 128 * Find appropriate route to use, based only on IP number. 129 */ 130 for(rt = ipddp_route_list; rt != NULL; rt = rt->next) 131 { 132 if(rt->ip == paddr) 133 break; 134 } 135 if(rt == NULL) { 136 spin_unlock(&ipddp_route_lock); 137 return NETDEV_TX_OK; 138 } 139 140 our_addr = atalk_find_dev_addr(rt->dev); 141 142 if(ipddp_mode == IPDDP_DECAP) 143 /* 144 * Pull off the excess room that should not be there. 145 * This is due to a hard-header problem. This is the 146 * quick fix for now though, till it breaks. 147 */ 148 skb_pull(skb, 35-(sizeof(struct ddpehdr)+1)); 149 150 /* Create the Extended DDP header */ 151 ddp = (struct ddpehdr *)skb->data; 152 ddp->deh_len_hops = htons(skb->len + (1<<10)); 153 ddp->deh_sum = 0; 154 155 /* 156 * For Localtalk we need aarp_send_ddp to strip the 157 * long DDP header and place a shot DDP header on it. 158 */ 159 if(rt->dev->type == ARPHRD_LOCALTLK) 160 { 161 ddp->deh_dnet = 0; 162 ddp->deh_snet = 0; 163 } 164 else 165 { 166 ddp->deh_dnet = rt->at.s_net; 167 ddp->deh_snet = our_addr->s_net; 168 } 169 ddp->deh_dnode = rt->at.s_node; 170 ddp->deh_snode = our_addr->s_node; 171 ddp->deh_dport = 72; 172 ddp->deh_sport = 72; 173 174 *((__u8 *)(ddp+1)) = 22; /* ddp type = IP */ 175 176 skb->protocol = htons(ETH_P_ATALK); /* Protocol has changed */ 177 178 dev->stats.tx_packets++; 179 dev->stats.tx_bytes += skb->len; 180 181 aarp_send_ddp(rt->dev, skb, &rt->at, NULL); 182 183 spin_unlock(&ipddp_route_lock); 184 185 return NETDEV_TX_OK; 186} 187 188/* 189 * Create a routing entry. We first verify that the 190 * record does not already exist. If it does we return -EEXIST 191 */ 192static int ipddp_create(struct ipddp_route *new_rt) 193{ 194 struct ipddp_route *rt = kmalloc(sizeof(*rt), GFP_KERNEL); 195 196 if (rt == NULL) 197 return -ENOMEM; 198 199 rt->ip = new_rt->ip; 200 rt->at = new_rt->at; 201 rt->next = NULL; 202 if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) { 203 kfree(rt); 204 return -ENETUNREACH; 205 } 206 207 spin_lock_bh(&ipddp_route_lock); 208 if (__ipddp_find_route(rt)) { 209 spin_unlock_bh(&ipddp_route_lock); 210 kfree(rt); 211 return -EEXIST; 212 } 213 214 rt->next = ipddp_route_list; 215 ipddp_route_list = rt; 216 217 spin_unlock_bh(&ipddp_route_lock); 218 219 return 0; 220} 221 222/* 223 * Delete a route, we only delete a FULL match. 224 * If route does not exist we return -ENOENT. 225 */ 226static int ipddp_delete(struct ipddp_route *rt) 227{ 228 struct ipddp_route **r = &ipddp_route_list; 229 struct ipddp_route *tmp; 230 231 spin_lock_bh(&ipddp_route_lock); 232 while((tmp = *r) != NULL) 233 { 234 if(tmp->ip == rt->ip && 235 tmp->at.s_net == rt->at.s_net && 236 tmp->at.s_node == rt->at.s_node) 237 { 238 *r = tmp->next; 239 spin_unlock_bh(&ipddp_route_lock); 240 kfree(tmp); 241 return 0; 242 } 243 r = &tmp->next; 244 } 245 246 spin_unlock_bh(&ipddp_route_lock); 247 return (-ENOENT); 248} 249 250/* 251 * Find a routing entry, we only return a FULL match 252 */ 253static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt) 254{ 255 struct ipddp_route *f; 256 257 for(f = ipddp_route_list; f != NULL; f = f->next) 258 { 259 if(f->ip == rt->ip && 260 f->at.s_net == rt->at.s_net && 261 f->at.s_node == rt->at.s_node) 262 return (f); 263 } 264 265 return (NULL); 266} 267 268static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 269{ 270 struct ipddp_route __user *rt = ifr->ifr_data; 271 struct ipddp_route rcp, rcp2, *rp; 272 273 if(!capable(CAP_NET_ADMIN)) 274 return -EPERM; 275 276 if(copy_from_user(&rcp, rt, sizeof(rcp))) 277 return -EFAULT; 278 279 switch(cmd) 280 { 281 case SIOCADDIPDDPRT: 282 return (ipddp_create(&rcp)); 283 284 case SIOCFINDIPDDPRT: 285 spin_lock_bh(&ipddp_route_lock); 286 rp = __ipddp_find_route(&rcp); 287 if (rp) 288 memcpy(&rcp2, rp, sizeof(rcp2)); 289 spin_unlock_bh(&ipddp_route_lock); 290 291 if (rp) { 292 if (copy_to_user(rt, &rcp2, 293 sizeof(struct ipddp_route))) 294 return -EFAULT; 295 return 0; 296 } else 297 return -ENOENT; 298 299 case SIOCDELIPDDPRT: 300 return (ipddp_delete(&rcp)); 301 302 default: 303 return -EINVAL; 304 } 305} 306 307static struct net_device *dev_ipddp; 308 309MODULE_LICENSE("GPL"); 310module_param(ipddp_mode, int, 0); 311 312static int __init ipddp_init_module(void) 313{ 314 dev_ipddp = ipddp_init(); 315 if (IS_ERR(dev_ipddp)) 316 return PTR_ERR(dev_ipddp); 317 return 0; 318} 319 320static void __exit ipddp_cleanup_module(void) 321{ 322 struct ipddp_route *p; 323 324 unregister_netdev(dev_ipddp); 325 free_netdev(dev_ipddp); 326 327 while (ipddp_route_list) { 328 p = ipddp_route_list->next; 329 kfree(ipddp_route_list); 330 ipddp_route_list = p; 331 } 332} 333 334module_init(ipddp_init_module); 335module_exit(ipddp_cleanup_module); 336