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