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         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 = skb->len;
 149         ddp->deh_hops = 1;
 150         ddp->deh_pad = 0;
 151         ddp->deh_sum = 0;
 152
 153         /*
 154          * For Localtalk we need aarp_send_ddp to strip the
 155          * long DDP header and place a shot DDP header on it.
 156          */
 157         if(rt->dev->type == ARPHRD_LOCALTLK)
 158         {
 159                 ddp->deh_dnet  = 0;   /* FIXME more hops?? */
 160                 ddp->deh_snet  = 0;
 161         }
 162         else
 163         {
 164                 ddp->deh_dnet  = rt->at.s_net;   /* FIXME more hops?? */
 165                 ddp->deh_snet  = our_addr->s_net;
 166         }
 167         ddp->deh_dnode = rt->at.s_node;
 168         ddp->deh_snode = our_addr->s_node;
 169         ddp->deh_dport = 72;
 170         ddp->deh_sport = 72;
 171
 172         *((__u8 *)(ddp+1)) = 22;                /* ddp type = IP */
 173         *((__u16 *)ddp)=ntohs(*((__u16 *)ddp)); /* fix up length field */
 174
 175         skb->protocol = htons(ETH_P_ATALK);     /* Protocol has changed */
 176
 177         ((struct net_device_stats *) dev->priv)->tx_packets++;
 178         ((struct net_device_stats *) dev->priv)->tx_bytes+=skb->len;
 179
 180         if(aarp_send_ddp(rt->dev, skb, &rt->at, NULL) < 0)
 181                 dev_kfree_skb(skb);
 182
 183         return 0;
 184 }
 185
 186 /*
 187  * Create a routing entry. We first verify that the
 188  * record does not already exist. If it does we return -EEXIST
 189  */
 190 static int ipddp_create(struct ipddp_route *new_rt)
 191 {
 192         struct ipddp_route *rt =(struct ipddp_route*) kmalloc(sizeof(*rt), GFP_KERNEL);
 193
 194         if (rt == NULL)
 195                 return -ENOMEM;
 196
 197         rt->ip = new_rt->ip;
 198         rt->at = new_rt->at;
 199         rt->next = NULL;
 200         if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) {
 201                 kfree(rt);
 202                 return -ENETUNREACH;
 203         }
 204
 205         if (ipddp_find_route(rt)) {
 206                 kfree(rt);
 207                 return -EEXIST;
 208         }
 209
 210         rt->next = ipddp_route_list;
 211         ipddp_route_list = rt;
 212
 213         return 0;
 214 }
 215
 216 /*
 217  * Delete a route, we only delete a FULL match.
 218  * If route does not exist we return -ENOENT.
 219  */
 220 static int ipddp_delete(struct ipddp_route *rt)
 221 {
 222         struct ipddp_route **r = &ipddp_route_list;
 223         struct ipddp_route *tmp;
 224
 225         while((tmp = *r) != NULL)
 226         {
 227                 if(tmp->ip == rt->ip
 228                         && tmp->at.s_net == rt->at.s_net
 229                         && tmp->at.s_node == rt->at.s_node)
 230                 {
 231                         *r = tmp->next;
 232                         kfree(tmp);
 233                         return 0;
 234                 }
 235                 r = &tmp->next;
 236         }
 237
 238         return (-ENOENT);
 239 }
 240
 241 /*
 242  * Find a routing entry, we only return a FULL match
 243  */
 244 static struct ipddp_route* ipddp_find_route(struct ipddp_route *rt)
 245 {
 246         struct ipddp_route *f;
 247
 248         for(f = ipddp_route_list; f != NULL; f = f->next)
 249         {
 250                 if(f->ip == rt->ip
 251                         && f->at.s_net == rt->at.s_net
 252                         && f->at.s_node == rt->at.s_node)
 253                         return (f);
 254         }
 255
 256         return (NULL);
 257 }
 258
 259 static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 260 {
 261         struct ipddp_route __user *rt = ifr->ifr_data;
 262         struct ipddp_route rcp;
 263
 264         if(!capable(CAP_NET_ADMIN))
 265                 return -EPERM;
 266
 267         if(copy_from_user(&rcp, rt, sizeof(rcp)))
 268                 return -EFAULT;
 269
 270         switch(cmd)
 271         {
 272                 case SIOCADDIPDDPRT:
 273                         return (ipddp_create(&rcp));
 274
 275                 case SIOCFINDIPDDPRT:
 276                         if(copy_to_user(rt, ipddp_find_route(&rcp), sizeof(struct ipddp_route)))
 277                                 return -EFAULT;
 278                         return 0;
 279
 280                 case SIOCDELIPDDPRT:
 281                         return (ipddp_delete(&rcp));
 282
 283                 default:
 284                         return -EINVAL;
 285         }
 286 }
 287
 288 static struct net_device *dev_ipddp;
 289
 290 MODULE_LICENSE("GPL");
 291 module_param(ipddp_mode, int, 0);
 292
 293 static int __init ipddp_init_module(void)
 294 {
 295         dev_ipddp = ipddp_init();
 296         if (IS_ERR(dev_ipddp))
 297                 return PTR_ERR(dev_ipddp);
 298         return 0;
 299 }
 300
 301 static void __exit ipddp_cleanup_module(void)
 302 {
 303         struct ipddp_route *p;
 304
 305         unregister_netdev(dev_ipddp);
 306         free_netdev(dev_ipddp);
 307
 308         while (ipddp_route_list) {
 309                 p = ipddp_route_list->next;
 310                 kfree(ipddp_route_list);
 311                 ipddp_route_list = p;
 312         }
 313 }
 314
 315 module_init(ipddp_init_module);
 316 module_exit(ipddp_cleanup_module);