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 <net/route.h> 35 #include <asm/uaccess.h> 36 37 #include "ipddp.h" /* Our stuff */ 38 39 static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n"; 40 41 static struct ipddp_route *ipddp_route_list; 42 43 #ifdef CONFIG_IPDDP_ENCAP 44 static int ipddp_mode = IPDDP_ENCAP; 45 #else 46 static int ipddp_mode = IPDDP_DECAP; 47 #endif 48 49 /* Index to functions, as function prototypes. */ 50 static int ipddp_xmit(struct sk_buff *skb, struct net_device *dev); 51 static struct net_device_stats *ipddp_get_stats(struct net_device *dev); 52 static int ipddp_create(struct ipddp_route *new_rt); 53 static int ipddp_delete(struct ipddp_route *rt); 54 static struct ipddp_route* ipddp_find_route(struct ipddp_route *rt); 55 static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 56 57 58 static struct net_device * __init ipddp_init(void) 59 { 60 static unsigned version_printed; 61 struct net_device *dev; 62 int err; 63 64 dev = alloc_etherdev(sizeof(struct net_device_stats)); 65 if (!dev) 66 return ERR_PTR(-ENOMEM); 67 68 SET_MODULE_OWNER(dev); 69 strcpy(dev->name, "ipddp%d"); 70 71 if (version_printed++ == 0) 72 printk(version); 73 74 /* Initalize the device structure. */ 75 dev->hard_start_xmit = ipddp_xmit; 76 dev->get_stats = ipddp_get_stats; 77 dev->do_ioctl = ipddp_ioctl; 78 79 dev->type = ARPHRD_IPDDP; /* IP over DDP tunnel */ 80 dev->mtu = 585; 81 dev->flags |= IFF_NOARP; 82 83 /* 84 * The worst case header we will need is currently a 85 * ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1) 86 * We send over SNAP so that takes another 8 bytes. 87 */ 88 dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1; 89 90 err = register_netdev(dev); 91 if (err) { 92 free_netdev(dev); 93 return ERR_PTR(err); 94 } 95 96 /* Let the user now what mode we are in */ 97 if(ipddp_mode == IPDDP_ENCAP) 98 printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n", 99 dev->name); 100 if(ipddp_mode == IPDDP_DECAP) 101 printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n", 102 dev->name); 103 104 return dev; 105 } 106 107 /* 108 * Get the current statistics. This may be called with the card open or closed. 109 */ 110 static struct net_device_stats *ipddp_get_stats(struct net_device *dev) 111 { 112 return dev->priv; 113 } 114 115 /* 116 * Transmit LLAP/ELAP frame using aarp_send_ddp. 117 */ 118 static int ipddp_xmit(struct sk_buff *skb, struct net_device *dev) 119 { 120 u32 paddr = ((struct rtable*)skb->dst)->rt_gateway; 121 struct ddpehdr *ddp; 122 struct ipddp_route *rt; 123 struct atalk_addr *our_addr; 124 125 /* 126 * Find appropriate route to use, based only on IP number. 127 */ 128 for(rt = ipddp_route_list; rt != NULL; rt = rt->next) 129 { 130 if(rt->ip == paddr) 131 break; 132 } 133 if(rt == NULL) 134 return 0; 135 136 our_addr = atalk_find_dev_addr(rt->dev); 137 138 if(ipddp_mode == IPDDP_DECAP) 139 /* 140 * Pull off the excess room that should not be there. 141 * This is due to a hard-header problem. This is the 142 * quick fix for now though, till it breaks. 143 */ 144 skb_pull(skb, 35-(sizeof(struct ddpehdr)+1)); 145 146 /* Create the Extended DDP header */ 147 ddp = (struct ddpehdr *)skb->data; 148 ddp->deh_len_hops = htons(skb->len + (1<<10)); 149 ddp->deh_sum = 0; 150 151 /* 152 * For Localtalk we need aarp_send_ddp to strip the 153 * long DDP header and place a shot DDP header on it. 154 */ 155 if(rt->dev->type == ARPHRD_LOCALTLK) 156 { 157 ddp->deh_dnet = 0; /* FIXME more hops?? */ 158 ddp->deh_snet = 0; 159 } 160 else 161 { 162 ddp->deh_dnet = rt->at.s_net; /* FIXME more hops?? */ 163 ddp->deh_snet = our_addr->s_net; 164 } 165 ddp->deh_dnode = rt->at.s_node; 166 ddp->deh_snode = our_addr->s_node; 167 ddp->deh_dport = 72; 168 ddp->deh_sport = 72; 169 170 *((__u8 *)(ddp+1)) = 22; /* ddp type = IP */ 171 172 skb->protocol = htons(ETH_P_ATALK); /* Protocol has changed */ 173 174 ((struct net_device_stats *) dev->priv)->tx_packets++; 175 ((struct net_device_stats *) dev->priv)->tx_bytes+=skb->len; 176 177 if(aarp_send_ddp(rt->dev, skb, &rt->at, NULL) < 0) 178 dev_kfree_skb(skb); 179 180 return 0; 181 } 182 183 /* 184 * Create a routing entry. We first verify that the 185 * record does not already exist. If it does we return -EEXIST 186 */ 187 static int ipddp_create(struct ipddp_route *new_rt) 188 { 189 struct ipddp_route *rt = kmalloc(sizeof(*rt), GFP_KERNEL); 190 191 if (rt == NULL) 192 return -ENOMEM; 193 194 rt->ip = new_rt->ip; 195 rt->at = new_rt->at; 196 rt->next = NULL; 197 if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) { 198 kfree(rt); 199 return -ENETUNREACH; 200 } 201 202 if (ipddp_find_route(rt)) { 203 kfree(rt); 204 return -EEXIST; 205 } 206 207 rt->next = ipddp_route_list; 208 ipddp_route_list = rt; 209 210 return 0; 211 } 212 213 /* 214 * Delete a route, we only delete a FULL match. 215 * If route does not exist we return -ENOENT. 216 */ 217 static int ipddp_delete(struct ipddp_route *rt) 218 { 219 struct ipddp_route **r = &ipddp_route_list; 220 struct ipddp_route *tmp; 221 222 while((tmp = *r) != NULL) 223 { 224 if(tmp->ip == rt->ip 225 && tmp->at.s_net == rt->at.s_net 226 && tmp->at.s_node == rt->at.s_node) 227 { 228 *r = tmp->next; 229 kfree(tmp); 230 return 0; 231 } 232 r = &tmp->next; 233 } 234 235 return (-ENOENT); 236 } 237 238 /* 239 * Find a routing entry, we only return a FULL match 240 */ 241 static struct ipddp_route* ipddp_find_route(struct ipddp_route *rt) 242 { 243 struct ipddp_route *f; 244 245 for(f = ipddp_route_list; f != NULL; f = f->next) 246 { 247 if(f->ip == rt->ip 248 && f->at.s_net == rt->at.s_net 249 && f->at.s_node == rt->at.s_node) 250 return (f); 251 } 252 253 return (NULL); 254 } 255 256 static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 257 { 258 struct ipddp_route __user *rt = ifr->ifr_data; 259 struct ipddp_route rcp; 260 261 if(!capable(CAP_NET_ADMIN)) 262 return -EPERM; 263 264 if(copy_from_user(&rcp, rt, sizeof(rcp))) 265 return -EFAULT; 266 267 switch(cmd) 268 { 269 case SIOCADDIPDDPRT: 270 return (ipddp_create(&rcp)); 271 272 case SIOCFINDIPDDPRT: 273 if(copy_to_user(rt, ipddp_find_route(&rcp), sizeof(struct ipddp_route))) 274 return -EFAULT; 275 return 0; 276 277 case SIOCDELIPDDPRT: 278 return (ipddp_delete(&rcp)); 279 280 default: 281 return -EINVAL; 282 } 283 } 284 285 static struct net_device *dev_ipddp; 286 287 MODULE_LICENSE("GPL"); 288 module_param(ipddp_mode, int, 0); 289 290 static int __init ipddp_init_module(void) 291 { 292 dev_ipddp = ipddp_init(); 293 if (IS_ERR(dev_ipddp)) 294 return PTR_ERR(dev_ipddp); 295 return 0; 296 } 297 298 static void __exit ipddp_cleanup_module(void) 299 { 300 struct ipddp_route *p; 301 302 unregister_netdev(dev_ipddp); 303 free_netdev(dev_ipddp); 304 305 while (ipddp_route_list) { 306 p = ipddp_route_list->next; 307 kfree(ipddp_route_list); 308 ipddp_route_list = p; 309 } 310 } 311 312 module_init(ipddp_init_module); 313 module_exit(ipddp_cleanup_module); 314