File: /usr/src/linux/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/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
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 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 */
106 static 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 */
114 static 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; /* FIXME more hops?? */
156 ddp->deh_snet = 0;
157 }
158 else
159 {
160 ddp->deh_dnet = rt->at.s_net; /* FIXME more hops?? */
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 */
186 static 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 */
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 *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
284 static struct net_device dev_ipddp;
285
286 MODULE_LICENSE("GPL");
287 MODULE_PARM(ipddp_mode, "i");
288
289 static 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
304 static 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
318 module_init(ipddp_init_module);
319 module_exit(ipddp_cleanup_module);
320