drivers/net/appletalk/ipddp.c

   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);