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/compat.h> 27 #include <linux/module.h> 28 #include <linux/kernel.h> 29 #include <linux/init.h> 30 #include <linux/netdevice.h> 31 #include <linux/etherdevice.h> 32 #include <linux/ip.h> 33 #include <linux/atalk.h> 34 #include <linux/if_arp.h> 35 #include <linux/slab.h> 36 #include <net/route.h> 37 #include <linux/uaccess.h> 38 39 #include "ipddp.h" /* Our stuff */ 40 41 static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n"; 42 43 static struct ipddp_route *ipddp_route_list; 44 static DEFINE_SPINLOCK(ipddp_route_lock); 45 46 #ifdef CONFIG_IPDDP_ENCAP 47 static int ipddp_mode = IPDDP_ENCAP; 48 #else 49 static int ipddp_mode = IPDDP_DECAP; 50 #endif 51 52 /* Index to functions, as function prototypes. */ 53 static netdev_tx_t ipddp_xmit(struct sk_buff *skb, 54 struct net_device *dev); 55 static int ipddp_create(struct ipddp_route *new_rt); 56 static int ipddp_delete(struct ipddp_route *rt); 57 static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt); 58 static int ipddp_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 59 void __user *data, int cmd); 60 61 static const struct net_device_ops ipddp_netdev_ops = { 62 .ndo_start_xmit = ipddp_xmit, 63 .ndo_siocdevprivate = ipddp_siocdevprivate, 64 .ndo_set_mac_address = eth_mac_addr, 65 .ndo_validate_addr = eth_validate_addr, 66 }; 67 68 static struct net_device * __init ipddp_init(void) 69 { 70 static unsigned version_printed; 71 struct net_device *dev; 72 int err; 73 74 dev = alloc_etherdev(0); 75 if (!dev) 76 return ERR_PTR(-ENOMEM); 77 78 netif_keep_dst(dev); 79 strcpy(dev->name, "ipddp%d"); 80 81 if (version_printed++ == 0) 82 printk(version); 83 84 /* Initialize the device structure. */ 85 dev->netdev_ops = &ipddp_netdev_ops; 86 87 dev->type = ARPHRD_IPDDP; /* IP over DDP tunnel */ 88 dev->mtu = 585; 89 dev->flags |= IFF_NOARP; 90 91 /* 92 * The worst case header we will need is currently a 93 * ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1) 94 * We send over SNAP so that takes another 8 bytes. 95 */ 96 dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1; 97 98 err = register_netdev(dev); 99 if (err) { 100 free_netdev(dev); 101 return ERR_PTR(err); 102 } 103 104 /* Let the user now what mode we are in */ 105 if(ipddp_mode == IPDDP_ENCAP) 106 printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n", 107 dev->name); 108 if(ipddp_mode == IPDDP_DECAP) 109 printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n", 110 dev->name); 111 112 return dev; 113 } 114 115 116 /* 117 * Transmit LLAP/ELAP frame using aarp_send_ddp. 118 */ 119 static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev) 120 { 121 struct rtable *rtable = skb_rtable(skb); 122 __be32 paddr = 0; 123 struct ddpehdr *ddp; 124 struct ipddp_route *rt; 125 struct atalk_addr *our_addr; 126 127 if (rtable->rt_gw_family == AF_INET) 128 paddr = rtable->rt_gw4; 129 130 spin_lock(&ipddp_route_lock); 131 132 /* 133 * Find appropriate route to use, based only on IP number. 134 */ 135 for(rt = ipddp_route_list; rt != NULL; rt = rt->next) 136 { 137 if(rt->ip == paddr) 138 break; 139 } 140 if(rt == NULL) { 141 spin_unlock(&ipddp_route_lock); 142 return NETDEV_TX_OK; 143 } 144 145 our_addr = atalk_find_dev_addr(rt->dev); 146 147 if(ipddp_mode == IPDDP_DECAP) 148 /* 149 * Pull off the excess room that should not be there. 150 * This is due to a hard-header problem. This is the 151 * quick fix for now though, till it breaks. 152 */ 153 skb_pull(skb, 35-(sizeof(struct ddpehdr)+1)); 154 155 /* Create the Extended DDP header */ 156 ddp = (struct ddpehdr *)skb->data; 157 ddp->deh_len_hops = htons(skb->len + (1<<10)); 158 ddp->deh_sum = 0; 159 160 /* 161 * For Localtalk we need aarp_send_ddp to strip the 162 * long DDP header and place a shot DDP header on it. 163 */ 164 if(rt->dev->type == ARPHRD_LOCALTLK) 165 { 166 ddp->deh_dnet = 0; /* FIXME more hops?? */ 167 ddp->deh_snet = 0; 168 } 169 else 170 { 171 ddp->deh_dnet = rt->at.s_net; /* FIXME more hops?? */ 172 ddp->deh_snet = our_addr->s_net; 173 } 174 ddp->deh_dnode = rt->at.s_node; 175 ddp->deh_snode = our_addr->s_node; 176 ddp->deh_dport = 72; 177 ddp->deh_sport = 72; 178 179 *((__u8 *)(ddp+1)) = 22; /* ddp type = IP */ 180 181 skb->protocol = htons(ETH_P_ATALK); /* Protocol has changed */ 182 183 dev->stats.tx_packets++; 184 dev->stats.tx_bytes += skb->len; 185 186 aarp_send_ddp(rt->dev, skb, &rt->at, NULL); 187 188 spin_unlock(&ipddp_route_lock); 189 190 return NETDEV_TX_OK; 191 } 192 193 /* 194 * Create a routing entry. We first verify that the 195 * record does not already exist. If it does we return -EEXIST 196 */ 197 static int ipddp_create(struct ipddp_route *new_rt) 198 { 199 struct ipddp_route *rt = kzalloc(sizeof(*rt), GFP_KERNEL); 200 201 if (rt == NULL) 202 return -ENOMEM; 203 204 rt->ip = new_rt->ip; 205 rt->at = new_rt->at; 206 rt->next = NULL; 207 if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) { 208 kfree(rt); 209 return -ENETUNREACH; 210 } 211 212 spin_lock_bh(&ipddp_route_lock); 213 if (__ipddp_find_route(rt)) { 214 spin_unlock_bh(&ipddp_route_lock); 215 kfree(rt); 216 return -EEXIST; 217 } 218 219 rt->next = ipddp_route_list; 220 ipddp_route_list = rt; 221 222 spin_unlock_bh(&ipddp_route_lock); 223 224 return 0; 225 } 226 227 /* 228 * Delete a route, we only delete a FULL match. 229 * If route does not exist we return -ENOENT. 230 */ 231 static int ipddp_delete(struct ipddp_route *rt) 232 { 233 struct ipddp_route **r = &ipddp_route_list; 234 struct ipddp_route *tmp; 235 236 spin_lock_bh(&ipddp_route_lock); 237 while((tmp = *r) != NULL) 238 { 239 if(tmp->ip == rt->ip && 240 tmp->at.s_net == rt->at.s_net && 241 tmp->at.s_node == rt->at.s_node) 242 { 243 *r = tmp->next; 244 spin_unlock_bh(&ipddp_route_lock); 245 kfree(tmp); 246 return 0; 247 } 248 r = &tmp->next; 249 } 250 251 spin_unlock_bh(&ipddp_route_lock); 252 return -ENOENT; 253 } 254 255 /* 256 * Find a routing entry, we only return a FULL match 257 */ 258 static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt) 259 { 260 struct ipddp_route *f; 261 262 for(f = ipddp_route_list; f != NULL; f = f->next) 263 { 264 if(f->ip == rt->ip && 265 f->at.s_net == rt->at.s_net && 266 f->at.s_node == rt->at.s_node) 267 return f; 268 } 269 270 return NULL; 271 } 272 273 static int ipddp_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 274 void __user *data, int cmd) 275 { 276 struct ipddp_route rcp, rcp2, *rp; 277 278 if (in_compat_syscall()) 279 return -EOPNOTSUPP; 280 281 if(!capable(CAP_NET_ADMIN)) 282 return -EPERM; 283 284 if (copy_from_user(&rcp, data, sizeof(rcp))) 285 return -EFAULT; 286 287 switch(cmd) 288 { 289 case SIOCADDIPDDPRT: 290 return ipddp_create(&rcp); 291 292 case SIOCFINDIPDDPRT: 293 spin_lock_bh(&ipddp_route_lock); 294 rp = __ipddp_find_route(&rcp); 295 if (rp) { 296 memset(&rcp2, 0, sizeof(rcp2)); 297 rcp2.ip = rp->ip; 298 rcp2.at = rp->at; 299 rcp2.flags = rp->flags; 300 } 301 spin_unlock_bh(&ipddp_route_lock); 302 303 if (rp) { 304 if (copy_to_user(data, &rcp2, 305 sizeof(struct ipddp_route))) 306 return -EFAULT; 307 return 0; 308 } else 309 return -ENOENT; 310 311 case SIOCDELIPDDPRT: 312 return ipddp_delete(&rcp); 313 314 default: 315 return -EINVAL; 316 } 317 } 318 319 static struct net_device *dev_ipddp; 320 321 MODULE_LICENSE("GPL"); 322 module_param(ipddp_mode, int, 0); 323 324 static int __init ipddp_init_module(void) 325 { 326 dev_ipddp = ipddp_init(); 327 return PTR_ERR_OR_ZERO(dev_ipddp); 328 } 329 330 static void __exit ipddp_cleanup_module(void) 331 { 332 struct ipddp_route *p; 333 334 unregister_netdev(dev_ipddp); 335 free_netdev(dev_ipddp); 336 337 while (ipddp_route_list) { 338 p = ipddp_route_list->next; 339 kfree(ipddp_route_list); 340 ipddp_route_list = p; 341 } 342 } 343 344 module_init(ipddp_init_module); 345 module_exit(ipddp_cleanup_module); 346