summaryrefslogtreecommitdiff
path: root/net/decnet/dn_rules.c
blob: faf7cc3483fe0822c26be6b915061ee8fdd8be9a (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
/*
 * 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:
 *              Steve Whitehouse <steve@chygwyn.com>
 *              Updated for Thomas Graf's generic rules
 *
 */
#include <linux/net.h>
#include <linux/init.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/fib_rules.h>
#include <net/dn.h>
#include <net/dn_fib.h>
#include <net/dn_neigh.h>
#include <net/dn_dev.h>
#include <net/dn_route.h>

static struct fib_rules_ops *dn_fib_rules_ops;

struct dn_fib_rule
{
	struct fib_rule		common;
	unsigned char		dst_len;
	unsigned char		src_len;
	__le16			src;
	__le16			srcmask;
	__le16			dst;
	__le16			dstmask;
	__le16			srcmap;
	u8			flags;
};


int dn_fib_lookup(struct flowidn *flp, struct dn_fib_res *res)
{
	struct fib_lookup_arg arg = {
		.result = res,
	};
	int err;

	err = fib_rules_lookup(dn_fib_rules_ops,
			       flowidn_to_flowi(flp), 0, &arg);
	res->r = arg.rule;

	return err;
}

static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp,
			      int flags, struct fib_lookup_arg *arg)
{
	struct flowidn *fld = &flp->u.dn;
	int err = -EAGAIN;
	struct dn_fib_table *tbl;

	switch(rule->action) {
	case FR_ACT_TO_TBL:
		break;

	case FR_ACT_UNREACHABLE:
		err = -ENETUNREACH;
		goto errout;

	case FR_ACT_PROHIBIT:
		err = -EACCES;
		goto errout;

	case FR_ACT_BLACKHOLE:
	default:
		err = -EINVAL;
		goto errout;
	}

	tbl = dn_fib_get_table(rule->table, 0);
	if (tbl == NULL)
		goto errout;

	err = tbl->lookup(tbl, fld, (struct dn_fib_res *)arg->result);
	if (err > 0)
		err = -EAGAIN;
errout:
	return err;
}

static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = {
	FRA_GENERIC_POLICY,
};

static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
	struct flowidn *fld = &fl->u.dn;
	__le16 daddr = fld->daddr;
	__le16 saddr = fld->saddr;

	if (((saddr ^ r->src) & r->srcmask) ||
	    ((daddr ^ r->dst) & r->dstmask))
		return 0;

	return 1;
}

static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
				 struct fib_rule_hdr *frh,
				 struct nlattr **tb)
{
	int err = -EINVAL;
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

	if (frh->tos)
		goto  errout;

	if (rule->table == RT_TABLE_UNSPEC) {
		if (rule->action == FR_ACT_TO_TBL) {
			struct dn_fib_table *table;

			table = dn_fib_empty_table();
			if (table == NULL) {
				err = -ENOBUFS;
				goto errout;
			}

			rule->table = table->n;
		}
	}

	if (frh->src_len)
		r->src = nla_get_le16(tb[FRA_SRC]);

	if (frh->dst_len)
		r->dst = nla_get_le16(tb[FRA_DST]);

	r->src_len = frh->src_len;
	r->srcmask = dnet_make_mask(r->src_len);
	r->dst_len = frh->dst_len;
	r->dstmask = dnet_make_mask(r->dst_len);
	err = 0;
errout:
	return err;
}

static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
			       struct nlattr **tb)
{
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

	if (frh->src_len && (r->src_len != frh->src_len))
		return 0;

	if (frh->dst_len && (r->dst_len != frh->dst_len))
		return 0;

	if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
		return 0;

	if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
		return 0;

	return 1;
}

unsigned int dnet_addr_type(__le16 addr)
{
	struct flowidn fld = { .daddr = addr };
	struct dn_fib_res res;
	unsigned int ret = RTN_UNICAST;
	struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);

	res.r = NULL;

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

static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
			    struct fib_rule_hdr *frh)
{
	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

	frh->dst_len = r->dst_len;
	frh->src_len = r->src_len;
	frh->tos = 0;

	if ((r->dst_len &&
	     nla_put_le16(skb, FRA_DST, r->dst)) ||
	    (r->src_len &&
	     nla_put_le16(skb, FRA_SRC, r->src)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -ENOBUFS;
}

static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
{
	dn_rt_cache_flush(-1);
}

static const struct fib_rules_ops __net_initconst dn_fib_rules_ops_template = {
	.family		= AF_DECnet,
	.rule_size	= sizeof(struct dn_fib_rule),
	.addr_size	= sizeof(u16),
	.action		= dn_fib_rule_action,
	.match		= dn_fib_rule_match,
	.configure	= dn_fib_rule_configure,
	.compare	= dn_fib_rule_compare,
	.fill		= dn_fib_rule_fill,
	.default_pref	= fib_default_rule_pref,
	.flush_cache	= dn_fib_rule_flush_cache,
	.nlgroup	= RTNLGRP_DECnet_RULE,
	.policy		= dn_fib_rule_policy,
	.owner		= THIS_MODULE,
	.fro_net	= &init_net,
};

void __init dn_fib_rules_init(void)
{
	dn_fib_rules_ops =
		fib_rules_register(&dn_fib_rules_ops_template, &init_net);
	BUG_ON(IS_ERR(dn_fib_rules_ops));
	BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff,
			            RT_TABLE_MAIN, 0));
}

void __exit dn_fib_rules_cleanup(void)
{
	fib_rules_unregister(dn_fib_rules_ops);
	rcu_barrier();
}