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/config.h> 27#include <linux/module.h> 28#include <linux/kernel.h> 29#include <linux/init.h> 30#include <linux/netdevice.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 39static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n"; 40 41static struct ipddp_route *ipddp_route_list; 42 43#ifdef CONFIG_IPDDP_ENCAP 44static int ipddp_mode = IPDDP_ENCAP; 45#else 46static int ipddp_mode = IPDDP_DECAP; 47#endif 48 49/* Index to functions, as function prototypes. */ 50static int ipddp_xmit(struct sk_buff *skb, struct net_device *dev); 51static struct net_device_stats *ipddp_get_stats(struct net_device *dev); 52static int ipddp_create(struct ipddp_route *new_rt); 53static int ipddp_delete(struct ipddp_route *rt); 54static struct ipddp_route* ipddp_find_route(struct ipddp_route *rt); 55static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 56 57 58static int __init ipddp_init(struct net_device *dev) 59{ 60 static unsigned version_printed; 61 62 SET_MODULE_OWNER(dev); 63 64 if (version_printed++ == 0) 65 printk(version); 66 67 /* Let the user now what mode we are in */ 68 if(ipddp_mode == IPDDP_ENCAP) 69 printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n", 70 dev->name); 71 if(ipddp_mode == IPDDP_DECAP) 72 printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n", 73 dev->name); 74 75 /* Fill in the device structure with ethernet-generic values. */ 76 ether_setup(dev); 77 78 /* Initalize the device structure. */ 79 dev->hard_start_xmit = ipddp_xmit; 80 81 dev->priv = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL); 82 if(!dev->priv) 83 return -ENOMEM; 84 memset(dev->priv,0,sizeof(struct net_device_stats)); 85 86 dev->get_stats = ipddp_get_stats; 87 dev->do_ioctl = ipddp_ioctl; 88 89 dev->type = ARPHRD_IPDDP; /* IP over DDP tunnel */ 90 dev->mtu = 585; 91 dev->flags |= IFF_NOARP; 92 93 /* 94 * The worst case header we will need is currently a 95 * ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1) 96 * We send over SNAP so that takes another 8 bytes. 97 */ 98 dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1; 99 100 return 0; 101} 102 103/* 104 * Get the current statistics. This may be called with the card open or closed. 105 */ 106static struct net_device_stats *ipddp_get_stats(struct net_device *dev) 107{ 108 return dev->priv; 109} 110 111/* 112 * Transmit LLAP/ELAP frame using aarp_send_ddp. 113 */ 114static int ipddp_xmit(struct sk_buff *skb, struct net_device *dev) 115{ 116 u32 paddr = ((struct rtable*)skb->dst)->rt_gateway; 117 struct ddpehdr *ddp; 118 struct ipddp_route *rt; 119 struct at_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 = skb->len; 145 ddp->deh_hops = 1; 146 ddp->deh_pad = 0; 147 ddp->deh_sum = 0; 148 149 /* 150 * For Localtalk we need aarp_send_ddp to strip the 151 * long DDP header and place a shot DDP header on it. 152 */ 153 if(rt->dev->type == ARPHRD_LOCALTLK) 154 { 155 ddp->deh_dnet = 0; 156 ddp->deh_snet = 0; 157 } 158 else 159 { 160 ddp->deh_dnet = rt->at.s_net; 161 ddp->deh_snet = our_addr->s_net; 162 } 163 ddp->deh_dnode = rt->at.s_node; 164 ddp->deh_snode = our_addr->s_node; 165 ddp->deh_dport = 72; 166 ddp->deh_sport = 72; 167 168 *((__u8 *)(ddp+1)) = 22; /* ddp type = IP */ 169 *((__u16 *)ddp)=ntohs(*((__u16 *)ddp)); /* fix up length field */ 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 */ 186static int ipddp_create(struct ipddp_route *new_rt) 187{ 188 struct ipddp_route *rt =(struct ipddp_route*) 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 */ 216static 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 */ 240static 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 255static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 256{ 257 struct ipddp_route *rt = (struct ipddp_route *)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 284static struct net_device dev_ipddp; 285 286MODULE_LICENSE("GPL"); 287MODULE_PARM(ipddp_mode, "i"); 288 289static int __init ipddp_init_module(void) 290{ 291 int err; 292 293 dev_ipddp.init = ipddp_init; 294 err=dev_alloc_name(&dev_ipddp, "ipddp%d"); 295 if(err < 0) 296 return err; 297 298 if(register_netdev(&dev_ipddp) != 0) 299 return -EIO; 300 301 return 0; 302} 303 304static void __exit ipddp_cleanup_module(void) 305{ 306 struct ipddp_route *p; 307 308 unregister_netdev(&dev_ipddp); 309 kfree(dev_ipddp.priv); 310 311 while (ipddp_route_list) { 312 p = ipddp_route_list->next; 313 kfree(ipddp_route_list); 314 ipddp_route_list = p; 315 } 316} 317 318module_init(ipddp_init_module); 319module_exit(ipddp_cleanup_module); 320