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