summaryrefslogtreecommitdiffstats
path: root/net/ipv6/fib6_rules.c
blob: 53b3998a486ced67d9eae000cff6c9a1269ecf66 (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
/*
 * net/ipv6/fib6_rules.c	IPv6 Routing Policy Rules
 *
 * Copyright (C)2003-2006 Helsinki University of Technology
 * Copyright (C)2003-2006 USAGI/WIDE Project
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation, version 2.
 *
 * Authors
 *	Thomas Graf		<tgraf@suug.ch>
 *	Ville Nuorvala		<vnuorval@tcs.hut.fi>
 */

#include <linux/netdevice.h>

#include <net/fib_rules.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/netlink.h>

struct fib6_rule
{
	struct fib_rule		common;
	struct rt6key		src;
	struct rt6key		dst;
	u8			tclass;
};

static struct fib_rules_ops fib6_rules_ops;

static struct fib6_rule main_rule = {
	.common = {
		.refcnt =	ATOMIC_INIT(2),
		.pref =		0x7FFE,
		.action =	FR_ACT_TO_TBL,
		.table =	RT6_TABLE_MAIN,
	},
};

static struct fib6_rule local_rule = {
	.common = {
		.refcnt =	ATOMIC_INIT(2),
		.pref =		0,
		.action =	FR_ACT_TO_TBL,
		.table =	RT6_TABLE_LOCAL,
		.flags =	FIB_RULE_PERMANENT,
	},
};

static LIST_HEAD(fib6_rules);

struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
				   pol_lookup_t lookup)
{
	struct fib_lookup_arg arg = {
		.lookup_ptr = lookup,
	};

	fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg);
	if (arg.rule)
		fib_rule_put(arg.rule);

	if (arg.result)
		return arg.result;

	dst_hold(&ip6_null_entry.u.dst);
	return &ip6_null_entry.u.dst;
}

static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
			    int flags, struct fib_lookup_arg *arg)
{
	struct rt6_info *rt = NULL;
	struct fib6_table *table;
	pol_lookup_t lookup = arg->lookup_ptr;

	switch (rule->action) {
	case FR_ACT_TO_TBL:
		break;
	case FR_ACT_UNREACHABLE:
		rt = &ip6_null_entry;
		goto discard_pkt;
	default:
	case FR_ACT_BLACKHOLE:
		rt = &ip6_blk_hole_entry;
		goto discard_pkt;
	case FR_ACT_PROHIBIT:
		rt = &ip6_prohibit_entry;
		goto discard_pkt;
	}

	table = fib6_get_table(rule->table);
	if (table)
		rt = lookup(table, flp, flags);

	if (rt != &ip6_null_entry) {
		struct fib6_rule *r = (struct fib6_rule *)rule;

		/*
		 * If we need to find a source address for this traffic,
		 * we check the result if it meets requirement of the rule.
		 */
		if ((rule->flags & FIB_RULE_FIND_SADDR) &&
		    r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
			struct in6_addr saddr;
			if (ipv6_get_saddr(&rt->u.dst, &flp->fl6_dst,
					   &saddr))
				goto again;
			if (!ipv6_prefix_equal(&saddr, &r->src.addr,
					       r->src.plen))
				goto again;
			ipv6_addr_copy(&flp->fl6_src, &saddr);
		}
		goto out;
	}
again:
	dst_release(&rt->u.dst);
	rt = NULL;
	goto out;

discard_pkt:
	dst_hold(&rt->u.dst);
out:
	arg->result = rt;
	return rt == NULL ? -EAGAIN : 0;
}


static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
	struct fib6_rule *r = (struct fib6_rule *) rule;

	if (r->dst.plen &&
	    !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
		return 0;

	/*
	 * If FIB_RULE_FIND_SADDR is set and we do not have a
	 * source address for the traffic, we defer check for
	 * source address.
	 */
	if (r->src.plen) {
		if (flags & RT6_LOOKUP_F_HAS_SADDR) {
			if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
					       r->src.plen))
				return 0;
		} else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
			return 0;
	}

	if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
		return 0;

	return 1;
}

static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
	FRA_GENERIC_POLICY,
};

static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
			       struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
			       struct nlattr **tb)
{
	int err = -EINVAL;
	struct fib6_rule *rule6 = (struct fib6_rule *) rule;

	if (rule->action == FR_ACT_TO_TBL) {
		if (rule->table == RT6_TABLE_UNSPEC)
			goto errout;

		if (fib6_new_table(rule->table) == NULL) {
			err = -ENOBUFS;
			goto errout;
		}
	}

	if (frh->src_len)
		nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
			   sizeof(struct in6_addr));

	if (frh->dst_len)
		nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
			   sizeof(struct in6_addr));

	rule6->src.plen = frh->src_len;
	rule6->dst.plen = frh->dst_len;
	rule6->tclass = frh->tos;

	err = 0;
errout:
	return err;
}

static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
			     struct nlattr **tb)
{
	struct fib6_rule *rule6 = (struct fib6_rule *) rule;

	if (frh->src_len && (rule6->src.plen != frh->src_len))
		return 0;

	if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
		return 0;

	if (frh->tos && (rule6->tclass != frh->tos))
		return 0;

	if (frh->src_len &&
	    nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
		return 0;

	if (frh->dst_len &&
	    nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
		return 0;

	return 1;
}

static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
			  struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
{
	struct fib6_rule *rule6 = (struct fib6_rule *) rule;

	frh->family = AF_INET6;
	frh->dst_len = rule6->dst.plen;
	frh->src_len = rule6->src.plen;
	frh->tos = rule6->tclass;

	if (rule6->dst.plen)
		NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
			&rule6->dst.addr);

	if (rule6->src.plen)
		NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
			&rule6->src.addr);

	return 0;

nla_put_failure:
	return -ENOBUFS;
}

static u32 fib6_rule_default_pref(void)
{
	return 0x3FFF;
}

static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
{
	return nla_total_size(16) /* dst */
	       + nla_total_size(16); /* src */
}

static struct fib_rules_ops fib6_rules_ops = {
	.family			= AF_INET6,
	.rule_size		= sizeof(struct fib6_rule),
	.addr_size		= sizeof(struct in6_addr),
	.action			= fib6_rule_action,
	.match			= fib6_rule_match,
	.configure		= fib6_rule_configure,
	.compare		= fib6_rule_compare,
	.fill			= fib6_rule_fill,
	.default_pref		= fib6_rule_default_pref,
	.nlmsg_payload		= fib6_rule_nlmsg_payload,
	.nlgroup		= RTNLGRP_IPV6_RULE,
	.policy			= fib6_rule_policy,
	.rules_list		= &fib6_rules,
	.owner			= THIS_MODULE,
};

void __init fib6_rules_init(void)
{
	list_add_tail(&local_rule.common.list, &fib6_rules);
	list_add_tail(&main_rule.common.list, &fib6_rules);

	fib_rules_register(&fib6_rules_ops);
}

void fib6_rules_cleanup(void)
{
	fib_rules_unregister(&fib6_rules_ops);
}