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