summaryrefslogtreecommitdiffstats
path: root/drivers/net/appletalk/ipddp.c
blob: 10d0dba572c2e319f630638e204ed8c12ae38b5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
/*
 *	ipddp.c: IP to Appletalk-IP Encapsulation driver for Linux
 *		 Appletalk-IP to IP Decapsulation driver for Linux
 *
 *	Authors:
 *      - DDP-IP Encap by: Bradford W. Johnson <johns393@maroon.tc.umn.edu>
 *	- DDP-IP Decap by: Jay Schulist <jschlst@samba.org>
 *
 *	Derived from:
 *	- Almost all code already existed in net/appletalk/ddp.c I just
 *	  moved/reorginized it into a driver file. Original IP-over-DDP code
 *	  was done by Bradford W. Johnson <johns393@maroon.tc.umn.edu>
 *      - skeleton.c: A network driver outline for linux.
 *        Written 1993-94 by Donald Becker.
 *	- dummy.c: A dummy net driver. By Nick Holloway.
 *	- MacGate: A user space Daemon for Appletalk-IP Decap for
 *	  Linux by Jay Schulist <jschlst@samba.org>
 *
 *      Copyright 1993 United States Government as represented by the
 *      Director, National Security Agency.
 *
 *      This software may be used and distributed according to the terms
 *      of the GNU General Public License, incorporated herein by reference.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ip.h>
#include <linux/atalk.h>
#include <linux/if_arp.h>
#include <linux/slab.h>
#include <net/route.h>
#include <asm/uaccess.h>

#include "ipddp.h"		/* Our stuff */

static const char version[] = KERN_INFO "ipddp.c:v0.01 8/28/97 Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n";

static struct ipddp_route *ipddp_route_list;
static DEFINE_SPINLOCK(ipddp_route_lock);

#ifdef CONFIG_IPDDP_ENCAP
static int ipddp_mode = IPDDP_ENCAP;
#else
static int ipddp_mode = IPDDP_DECAP;
#endif

/* Index to functions, as function prototypes. */
static netdev_tx_t ipddp_xmit(struct sk_buff *skb,
				    struct net_device *dev);
static int ipddp_create(struct ipddp_route *new_rt);
static int ipddp_delete(struct ipddp_route *rt);
static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt);
static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);

static const struct net_device_ops ipddp_netdev_ops = {
	.ndo_start_xmit		= ipddp_xmit,
	.ndo_do_ioctl   	= ipddp_ioctl,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_set_mac_address 	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};

static struct net_device * __init ipddp_init(void)
{
	static unsigned version_printed;
	struct net_device *dev;
	int err;

	dev = alloc_etherdev(0);
	if (!dev)
		return ERR_PTR(-ENOMEM);

	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
	strcpy(dev->name, "ipddp%d");

	if (version_printed++ == 0)
                printk(version);

	/* Initialize the device structure. */
	dev->netdev_ops = &ipddp_netdev_ops;

        dev->type = ARPHRD_IPDDP;       	/* IP over DDP tunnel */
        dev->mtu = 585;
        dev->flags |= IFF_NOARP;

        /*
         *      The worst case header we will need is currently a
         *      ethernet header (14 bytes) and a ddp header (sizeof ddpehdr+1)
         *      We send over SNAP so that takes another 8 bytes.
         */
        dev->hard_header_len = 14+8+sizeof(struct ddpehdr)+1;

	err = register_netdev(dev);
	if (err) {
		free_netdev(dev);
		return ERR_PTR(err);
	}

	/* Let the user now what mode we are in */
	if(ipddp_mode == IPDDP_ENCAP)
		printk("%s: Appletalk-IP Encap. mode by Bradford W. Johnson <johns393@maroon.tc.umn.edu>\n", 
			dev->name);
	if(ipddp_mode == IPDDP_DECAP)
		printk("%s: Appletalk-IP Decap. mode by Jay Schulist <jschlst@samba.org>\n", 
			dev->name);

        return dev;
}


/*
 * Transmit LLAP/ELAP frame using aarp_send_ddp.
 */
static netdev_tx_t ipddp_xmit(struct sk_buff *skb, struct net_device *dev)
{
	__be32 paddr = skb_rtable(skb)->rt_gateway;
        struct ddpehdr *ddp;
        struct ipddp_route *rt;
        struct atalk_addr *our_addr;

	spin_lock(&ipddp_route_lock);

	/*
         * Find appropriate route to use, based only on IP number.
         */
        for(rt = ipddp_route_list; rt != NULL; rt = rt->next)
        {
                if(rt->ip == paddr)
                        break;
        }
        if(rt == NULL) {
		spin_unlock(&ipddp_route_lock);
                return NETDEV_TX_OK;
	}

        our_addr = atalk_find_dev_addr(rt->dev);

	if(ipddp_mode == IPDDP_DECAP)
		/* 
		 * Pull off the excess room that should not be there.
		 * This is due to a hard-header problem. This is the
		 * quick fix for now though, till it breaks.
		 */
		skb_pull(skb, 35-(sizeof(struct ddpehdr)+1));

	/* Create the Extended DDP header */
	ddp = (struct ddpehdr *)skb->data;
        ddp->deh_len_hops = htons(skb->len + (1<<10));
        ddp->deh_sum = 0;

	/*
         * For Localtalk we need aarp_send_ddp to strip the
         * long DDP header and place a shot DDP header on it.
         */
        if(rt->dev->type == ARPHRD_LOCALTLK)
        {
                ddp->deh_dnet  = 0;   /* FIXME more hops?? */
                ddp->deh_snet  = 0;
        }
        else
        {
                ddp->deh_dnet  = rt->at.s_net;   /* FIXME more hops?? */
                ddp->deh_snet  = our_addr->s_net;
        }
        ddp->deh_dnode = rt->at.s_node;
        ddp->deh_snode = our_addr->s_node;
        ddp->deh_dport = 72;
        ddp->deh_sport = 72;

        *((__u8 *)(ddp+1)) = 22;        	/* ddp type = IP */

        skb->protocol = htons(ETH_P_ATALK);     /* Protocol has changed */

	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;

	aarp_send_ddp(rt->dev, skb, &rt->at, NULL);

	spin_unlock(&ipddp_route_lock);

        return NETDEV_TX_OK;
}

/*
 * Create a routing entry. We first verify that the
 * record does not already exist. If it does we return -EEXIST
 */
static int ipddp_create(struct ipddp_route *new_rt)
{
        struct ipddp_route *rt = kmalloc(sizeof(*rt), GFP_KERNEL);

        if (rt == NULL)
                return -ENOMEM;

        rt->ip = new_rt->ip;
        rt->at = new_rt->at;
        rt->next = NULL;
        if ((rt->dev = atrtr_get_dev(&rt->at)) == NULL) {
		kfree(rt);
                return -ENETUNREACH;
        }

	spin_lock_bh(&ipddp_route_lock);
	if (__ipddp_find_route(rt)) {
		spin_unlock_bh(&ipddp_route_lock);
		kfree(rt);
		return -EEXIST;
	}

        rt->next = ipddp_route_list;
        ipddp_route_list = rt;

	spin_unlock_bh(&ipddp_route_lock);

        return 0;
}

/*
 * Delete a route, we only delete a FULL match.
 * If route does not exist we return -ENOENT.
 */
static int ipddp_delete(struct ipddp_route *rt)
{
        struct ipddp_route **r = &ipddp_route_list;
        struct ipddp_route *tmp;

	spin_lock_bh(&ipddp_route_lock);
        while((tmp = *r) != NULL)
        {
                if(tmp->ip == rt->ip &&
		   tmp->at.s_net == rt->at.s_net &&
		   tmp->at.s_node == rt->at.s_node)
                {
                        *r = tmp->next;
			spin_unlock_bh(&ipddp_route_lock);
                        kfree(tmp);
                        return 0;
                }
                r = &tmp->next;
        }

	spin_unlock_bh(&ipddp_route_lock);
        return -ENOENT;
}

/*
 * Find a routing entry, we only return a FULL match
 */
static struct ipddp_route* __ipddp_find_route(struct ipddp_route *rt)
{
        struct ipddp_route *f;

        for(f = ipddp_route_list; f != NULL; f = f->next)
        {
                if(f->ip == rt->ip &&
		   f->at.s_net == rt->at.s_net &&
		   f->at.s_node == rt->at.s_node)
                        return f;
        }

        return NULL;
}

static int ipddp_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct ipddp_route __user *rt = ifr->ifr_data;
        struct ipddp_route rcp, rcp2, *rp;

        if(!capable(CAP_NET_ADMIN))
                return -EPERM;

	if(copy_from_user(&rcp, rt, sizeof(rcp)))
		return -EFAULT;

        switch(cmd)
        {
		case SIOCADDIPDDPRT:
                        return ipddp_create(&rcp);

                case SIOCFINDIPDDPRT:
			spin_lock_bh(&ipddp_route_lock);
			rp = __ipddp_find_route(&rcp);
			if (rp)
				memcpy(&rcp2, rp, sizeof(rcp2));
			spin_unlock_bh(&ipddp_route_lock);

			if (rp) {
				if (copy_to_user(rt, &rcp2,
						 sizeof(struct ipddp_route)))
					return -EFAULT;
				return 0;
			} else
				return -ENOENT;

                case SIOCDELIPDDPRT:
                        return ipddp_delete(&rcp);

                default:
                        return -EINVAL;
        }
}

static struct net_device *dev_ipddp;

MODULE_LICENSE("GPL");
module_param(ipddp_mode, int, 0);

static int __init ipddp_init_module(void)
{
	dev_ipddp = ipddp_init();
        if (IS_ERR(dev_ipddp))
                return PTR_ERR(dev_ipddp);
	return 0;
}

static void __exit ipddp_cleanup_module(void)
{
        struct ipddp_route *p;

	unregister_netdev(dev_ipddp);
        free_netdev(dev_ipddp);

        while (ipddp_route_list) {
                p = ipddp_route_list->next;
                kfree(ipddp_route_list);
                ipddp_route_list = p;
        }
}

module_init(ipddp_init_module);
module_exit(ipddp_cleanup_module);
OpenPOWER on IntegriCloud