aboutsummaryrefslogtreecommitdiff
path: root/net/decnet/dn_rules.c
blob: 06e785fe575798b5ae736317a44ec67d8ca07c11 (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
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425

/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet Routing Forwarding Information Base (Rules)
 *
 * Author:      Steve Whitehouse <SteveW@ACM.org>
 *              Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
 *
 *
 * Changes:
 *
 */
#include <linux/string.h>
#include <linux/net.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/proc_fs.h>
#include <linux/netdevice.h>
#include <linux/timer.h>
#include <linux/spinlock.h>
#include <linux/in_route.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_fib.h>
#include <net/dn_neigh.h>
#include <net/dn_dev.h>

struct dn_fib_rule
{
	struct hlist_node	r_hlist;
	atomic_t		r_clntref;
	u32			r_preference;
	unsigned char		r_table;
	unsigned char		r_action;
	unsigned char		r_dst_len;
	unsigned char		r_src_len;
	__le16			r_src;
	__le16			r_srcmask;
	__le16			r_dst;
	__le16			r_dstmask;
	__le16			r_srcmap;
	u8			r_flags;
#ifdef CONFIG_DECNET_ROUTE_FWMARK
	u32			r_fwmark;
#endif
	int			r_ifindex;
	char			r_ifname[IFNAMSIZ];
	int			r_dead;
	struct rcu_head		rcu;
};

static struct dn_fib_rule default_rule = {
	.r_clntref =		ATOMIC_INIT(2),
	.r_preference =		0x7fff,
	.r_table =		RT_TABLE_MAIN,
	.r_action =		RTN_UNICAST
};

static struct hlist_head dn_fib_rules;

int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct rtmsg *rtm = NLMSG_DATA(nlh);
	struct dn_fib_rule *r;
	struct hlist_node *node;
	int err = -ESRCH;

	hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
		if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) &&
			rtm->rtm_src_len == r->r_src_len &&
			rtm->rtm_dst_len == r->r_dst_len &&
			(!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) &&
#ifdef CONFIG_DECNET_ROUTE_FWMARK
			(!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
#endif
			(!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
			(!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
			(!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
			(!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {

			err = -EPERM;
			if (r == &default_rule)
				break;

			hlist_del_rcu(&r->r_hlist);
			r->r_dead = 1;
			dn_fib_rule_put(r);
			err = 0;
			break;
		}
	}

	return err;
}

static inline void dn_fib_rule_put_rcu(struct rcu_head *head)
{
	struct dn_fib_rule *r = container_of(head, struct dn_fib_rule, rcu);
	kfree(r);
}

void dn_fib_rule_put(struct dn_fib_rule *r)
{
	if (atomic_dec_and_test(&r->r_clntref)) {
		if (r->r_dead)
			call_rcu(&r->rcu, dn_fib_rule_put_rcu);
		else
			printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n");
	}
}


int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct rtmsg *rtm = NLMSG_DATA(nlh);
	struct dn_fib_rule *r, *new_r, *last = NULL;
	struct hlist_node *node = NULL;
	unsigned char table_id;

	if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16)
		return -EINVAL;

	if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
		return -EINVAL;

	if (rtm->rtm_type == RTN_NAT)
		return -EINVAL;

	table_id = rtm->rtm_table;
	if (table_id == RT_TABLE_UNSPEC) {
		struct dn_fib_table *tb;
		if (rtm->rtm_type == RTN_UNICAST) {
			if ((tb = dn_fib_empty_table()) == NULL)
				return -ENOBUFS;
			table_id = tb->n;
		}
	}

	new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
	if (!new_r)
		return -ENOMEM;
	memset(new_r, 0, sizeof(*new_r));

	if (rta[RTA_SRC-1])
		memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2);
	if (rta[RTA_DST-1])
		memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2);
	if (rta[RTA_GATEWAY-1])
		memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 2);
	new_r->r_src_len = rtm->rtm_src_len;
	new_r->r_dst_len = rtm->rtm_dst_len;
	new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len);
	new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len);
#ifdef CONFIG_DECNET_ROUTE_FWMARK
	if (rta[RTA_PROTOINFO-1])
		memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
#endif
	new_r->r_action = rtm->rtm_type;
	new_r->r_flags = rtm->rtm_flags;
	if (rta[RTA_PRIORITY-1])
		memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
	new_r->r_table = table_id;
	if (rta[RTA_IIF-1]) {
		struct net_device *dev;
		rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
		new_r->r_ifindex = -1;
		dev = dev_get_by_name(new_r->r_ifname);
		if (dev) {
			new_r->r_ifindex = dev->ifindex;
			dev_put(dev);
		}
	}

	r = container_of(dn_fib_rules.first, struct dn_fib_rule, r_hlist);
	if (!new_r->r_preference) {
		if (r && r->r_hlist.next != NULL) {
			r = container_of(r->r_hlist.next, struct dn_fib_rule, r_hlist);
			if (r->r_preference)
				new_r->r_preference = r->r_preference - 1;
		}
	}

	hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
		if (r->r_preference > new_r->r_preference)
			break;
		last = r;
	}
	atomic_inc(&new_r->r_clntref);

	if (last)
		hlist_add_after_rcu(&last->r_hlist, &new_r->r_hlist);
	else
		hlist_add_before_rcu(&new_r->r_hlist, &r->r_hlist);
	return 0;
}


int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
{
	struct dn_fib_rule *r, *policy;
	struct dn_fib_table *tb;
	__le16 saddr = flp->fld_src;
	__le16 daddr = flp->fld_dst;
	struct hlist_node *node;
	int err;

	rcu_read_lock();

	hlist_for_each_entry_rcu(r, node, &dn_fib_rules, r_hlist) {
		if (((saddr^r->r_src) & r->r_srcmask) ||
		    ((daddr^r->r_dst) & r->r_dstmask) ||
#ifdef CONFIG_DECNET_ROUTE_FWMARK
		    (r->r_fwmark && r->r_fwmark != flp->fld_fwmark) ||
#endif
		    (r->r_ifindex && r->r_ifindex != flp->iif))
			continue;

		switch(r->r_action) {
			case RTN_UNICAST:
			case RTN_NAT:
				policy = r;
				break;
			case RTN_UNREACHABLE:
				rcu_read_unlock();
				return -ENETUNREACH;
			default:
			case RTN_BLACKHOLE:
				rcu_read_unlock();
				return -EINVAL;
			case RTN_PROHIBIT:
				rcu_read_unlock();
				return -EACCES;
		}

		if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL)
			continue;
		err = tb->lookup(tb, flp, res);
		if (err == 0) {
			res->r = policy;
			if (policy)
				atomic_inc(&policy->r_clntref);
			rcu_read_unlock();
			return 0;
		}
		if (err < 0 && err != -EAGAIN) {
			rcu_read_unlock();
			return err;
		}
	}

	rcu_read_unlock();
	return -ESRCH;
}

unsigned dnet_addr_type(__le16 addr)
{
	struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } };
	struct dn_fib_res res;
	unsigned ret = RTN_UNICAST;
	struct dn_fib_table *tb = dn_fib_tables[RT_TABLE_LOCAL];

	res.r = NULL;

	if (tb) {
		if (!tb->lookup(tb, &fl, &res)) {
			ret = res.type;
			dn_fib_res_put(&res);
		}
	}
	return ret;
}

__le16 dn_fib_rules_policy(__le16 saddr, struct dn_fib_res *res, unsigned *flags)
{
	struct dn_fib_rule *r = res->r;

	if (r->r_action == RTN_NAT) {
		int addrtype = dnet_addr_type(r->r_srcmap);

		if (addrtype == RTN_NAT) {
			saddr = (saddr&~r->r_srcmask)|r->r_srcmap;
			*flags |= RTCF_SNAT;
		} else if (addrtype == RTN_LOCAL || r->r_srcmap == 0) {
			saddr = r->r_srcmap;
			*flags |= RTCF_MASQ;
		}
	}
	return saddr;
}

static void dn_fib_rules_detach(struct net_device *dev)
{
	struct hlist_node *node;
	struct dn_fib_rule *r;

	hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
		if (r->r_ifindex == dev->ifindex)
			r->r_ifindex = -1;
	}
}

static void dn_fib_rules_attach(struct net_device *dev)
{
	struct hlist_node *node;
	struct dn_fib_rule *r;

	hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
		if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
			r->r_ifindex = dev->ifindex;
	}
}

static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;

	switch(event) {
		case NETDEV_UNREGISTER:
			dn_fib_rules_detach(dev);
			dn_fib_sync_down(0, dev, 1);
		case NETDEV_REGISTER:
			dn_fib_rules_attach(dev);
			dn_fib_sync_up(dev);
	}

	return NOTIFY_DONE;
}


static struct notifier_block dn_fib_rules_notifier = {
	.notifier_call =	dn_fib_rules_event,
};

static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r,
			    struct netlink_callback *cb, unsigned int flags)
{
	struct rtmsg *rtm;
	struct nlmsghdr *nlh;
	unsigned char *b = skb->tail;


	nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags);
	rtm = NLMSG_DATA(nlh);
	rtm->rtm_family = AF_DECnet;
	rtm->rtm_dst_len = r->r_dst_len;
	rtm->rtm_src_len = r->r_src_len;
	rtm->rtm_tos = 0;
#ifdef CONFIG_DECNET_ROUTE_FWMARK
	if (r->r_fwmark)
		RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
#endif
	rtm->rtm_table = r->r_table;
	rtm->rtm_protocol = 0;
	rtm->rtm_scope = 0;
	rtm->rtm_type = r->r_action;
	rtm->rtm_flags = r->r_flags;

	if (r->r_dst_len)
		RTA_PUT(skb, RTA_DST, 2, &r->r_dst);
	if (r->r_src_len)
		RTA_PUT(skb, RTA_SRC, 2, &r->r_src);
	if (r->r_ifname[0])
		RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
	if (r->r_preference)
		RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
	if (r->r_srcmap)
		RTA_PUT(skb, RTA_GATEWAY, 2, &r->r_srcmap);
	nlh->nlmsg_len = skb->tail - b;
	return skb->len;

nlmsg_failure:
rtattr_failure:
	skb_trim(skb, b - skb->data);
	return -1;
}

int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx = 0;
	int s_idx = cb->args[0];
	struct dn_fib_rule *r;
	struct hlist_node *node;

	rcu_read_lock();
	hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
		if (idx < s_idx)
			continue;
		if (dn_fib_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
			break;
		idx++;
	}
	rcu_read_unlock();
	cb->args[0] = idx;

	return skb->len;
}

void __init dn_fib_rules_init(void)
{
	INIT_HLIST_HEAD(&dn_fib_rules);
	hlist_add_head(&default_rule.r_hlist, &dn_fib_rules);
	register_netdevice_notifier(&dn_fib_rules_notifier);
}

void __exit dn_fib_rules_cleanup(void)
{
	unregister_netdevice_notifier(&dn_fib_rules_notifier);
}