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 <linux/uaccess.h> 37 38 #include "ipddp.h" /* Our stuff */ 39 40 static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n"; 41 42 static struct ipddp_route *ipddp_route_list; 43 static DEFINE_SPINLOCK(ipddp_route_lock); 44 45 #ifdef CONFIG_IPDDP_ENCAP 46 static int ipddp_mode = IPDDP_ENCAP; 47 #else 48 static int ipddp_mode = IPDDP_DECAP; 49 #endif 50 51 /* Index to functions, as function prototypes. */ 52 static netdev_tx_t ipddp_xmit(struct sk_buff *skb, 53 struct net_device *dev); 54 static int ipddp_create(struct ipddp_route *new_rt); 55 static int ipddp_delete(struct ipddp_route *rt); 56 static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt); 57 static int ipddp_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 58 void __user *data, int cmd); 59 60 static const struct net_device_ops ipddp_netdev_ops = { 61 .ndo_start_xmit = ipddp_xmit, 62 .ndo_siocdevprivate = ipddp_siocdevprivate, 63 .ndo_set_mac_address = eth_mac_addr, 64 .ndo_validate_addr = eth_validate_addr, 65 }; 66 67 static 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 netif_keep_dst(dev); 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 */ 118 static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev) 119 { 120 struct rtable *rtable = skb_rtable(skb); 121 __be32 paddr = 0; 122 struct ddpehdr *ddp; 123 struct ipddp_route *rt; 124 struct atalk_addr *our_addr; 125 126 if (rtable->rt_gw_family == AF_INET) 127 paddr = rtable->rt_gw4; 128 129 spin_lock(&ipddp_route_lock); 130 131 /* 132 * Find appropriate route to use, based only on IP number. 133 */ 134 for(rt = ipddp_route_list; rt != NULL; rt = rt->next) 135 { 136 if(rt->ip == paddr) 137 break; 138 } 139 if(rt == NULL) { 140 spin_unlock(&ipddp_route_lock); 141 return NETDEV_TX_OK; 142 } 143 144 our_addr = atalk_find_dev_addr(rt->dev); 145 146 if(ipddp_mode == IPDDP_DECAP) 147 /* 148 * Pull off the excess room that should not be there. 149 * This is due to a hard-header problem. This is the 150 * quick fix for now though, till it breaks. 151 */ 152 skb_pull(skb, 35-(sizeof(struct ddpehdr)+1)); 153 154 /* Create the Extended DDP header */ 155 ddp = (struct ddpehdr *)skb->data; 156 ddp->deh_len_hops = htons(skb->len + (1<<10)); 157 ddp->deh_sum = 0; 158 159 /* 160 * For Localtalk we need aarp_send_ddp to strip the 161 * long DDP header and place a shot DDP header on it. 162 */ 163 if(rt->dev->type == ARPHRD_LOCALTLK) 164 { 165 ddp->deh_dnet = 0; /* FIXME more hops?? */ 166 ddp->deh_snet = 0; 167 } 168 else 169 { 170 ddp->deh_dnet = rt->at.s_net; /* FIXME more hops?? */ 171 ddp->deh_snet = our_addr->s_net; 172 } 173 ddp->deh_dnode = rt->at.s_node; 174 ddp->deh_snode = our_addr->s_node; 175 ddp->deh_dport = 72; 176 ddp->deh_sport = 72; 177 178 *((__u8 *)(ddp+1)) = 22; /* ddp type = IP */ 179 180 skb->protocol = htons(ETH_P_ATALK); /* Protocol has changed */ 181 182 dev->stats.tx_packets++; 183 dev->stats.tx_bytes += skb->len; 184 185 aarp_send_ddp(rt->dev, skb, &rt->at, NULL); 186 187 spin_unlock(&ipddp_route_lock); 188 189 return NETDEV_TX_OK; 190 } 191 192 /* 193 * Create a routing entry. We first verify that the 194 * record does not already exist. If it does we return -EEXIST 195 */ 196 static int ipddp_create(struct ipddp_route *new_rt) 197 { 198 struct ipddp_route *rt = kzalloc(sizeof(*rt), GFP_KERNEL); 199 200 if (rt == NULL) 201 return -ENOMEM; 202 203 rt->ip = new_rt->ip; 204 rt->at = new_rt->at; 205 rt->next = NULL; 206 if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) { 207 kfree(rt); 208 return -ENETUNREACH; 209 } 210 211 spin_lock_bh(&ipddp_route_lock); 212 if (__ipddp_find_route(rt)) { 213 spin_unlock_bh(&ipddp_route_lock); 214 kfree(rt); 215 return -EEXIST; 216 } 217 218 rt->next = ipddp_route_list; 219 ipddp_route_list = rt; 220 221 spin_unlock_bh(&ipddp_route_lock); 222 223 return 0; 224 } 225 226 /* 227 * Delete a route, we only delete a FULL match. 228 * If route does not exist we return -ENOENT. 229 */ 230 static int ipddp_delete(struct ipddp_route *rt) 231 { 232 struct ipddp_route **r = &ipddp_route_list; 233 struct ipddp_route *tmp; 234 235 spin_lock_bh(&ipddp_route_lock); 236 while((tmp = *r) != NULL) 237 { 238 if(tmp->ip == rt->ip && 239 tmp->at.s_net == rt->at.s_net && 240 tmp->at.s_node == rt->at.s_node) 241 { 242 *r = tmp->next; 243 spin_unlock_bh(&ipddp_route_lock); 244 kfree(tmp); 245 return 0; 246 } 247 r = &tmp->next; 248 } 249 250 spin_unlock_bh(&ipddp_route_lock); 251 return -ENOENT; 252 } 253 254 /* 255 * Find a routing entry, we only return a FULL match 256 */ 257 static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt) 258 { 259 struct ipddp_route *f; 260 261 for(f = ipddp_route_list; f != NULL; f = f->next) 262 { 263 if(f->ip == rt->ip && 264 f->at.s_net == rt->at.s_net && 265 f->at.s_node == rt->at.s_node) 266 return f; 267 } 268 269 return NULL; 270 } 271 272 static int ipddp_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 273 void __user *data, int cmd) 274 { 275 struct ipddp_route rcp, rcp2, *rp; 276 277 if (in_compat_syscall()) 278 return -EOPNOTSUPP; 279 280 if(!capable(CAP_NET_ADMIN)) 281 return -EPERM; 282 283 if (copy_from_user(&rcp, data, sizeof(rcp))) 284 return -EFAULT; 285 286 switch(cmd) 287 { 288 case SIOCADDIPDDPRT: 289 return ipddp_create(&rcp); 290 291 case SIOCFINDIPDDPRT: 292 spin_lock_bh(&ipddp_route_lock); 293 rp = __ipddp_find_route(&rcp); 294 if (rp) { 295 memset(&rcp2, 0, sizeof(rcp2)); 296 rcp2.ip = rp->ip; 297 rcp2.at = rp->at; 298 rcp2.flags = rp->flags; 299 } 300 spin_unlock_bh(&ipddp_route_lock); 301 302 if (rp) { 303 if (copy_to_user(data, &rcp2, 304 sizeof(struct ipddp_route))) 305 return -EFAULT; 306 return 0; 307 } else 308 return -ENOENT; 309 310 case SIOCDELIPDDPRT: 311 return ipddp_delete(&rcp); 312 313 default: 314 return -EINVAL; 315 } 316 } 317 318 static struct net_device *dev_ipddp; 319 320 MODULE_LICENSE("GPL"); 321 module_param(ipddp_mode, int, 0); 322 323 static int __init ipddp_init_module(void) 324 { 325 dev_ipddp = ipddp_init(); 326 return PTR_ERR_OR_ZERO(dev_ipddp); 327 } 328 329 static void __exit ipddp_cleanup_module(void) 330 { 331 struct ipddp_route *p; 332 333 unregister_netdev(dev_ipddp); 334 free_netdev(dev_ipddp); 335 336 while (ipddp_route_list) { 337 p = ipddp_route_list->next; 338 kfree(ipddp_route_list); 339 ipddp_route_list = p; 340 } 341 } 342 343 module_init(ipddp_init_module); 344 module_exit(ipddp_cleanup_module); 345