fib6_rules.c revision 366e4adc0f9ef33f56c62f980a7d83775e64abd0 
1/*
2 * net/ipv6/fib6_rules.c	IPv6 Routing Policy Rules
3 *
4 * Copyright (C)2003-2006 Helsinki University of Technology
5 * Copyright (C)2003-2006 USAGI/WIDE Project
6 *
7 *	This program is free software; you can redistribute it and/or
8 *	modify it under the terms of the GNU General Public License as
9 *	published by the Free Software Foundation, version 2.
10 *
11 * Authors
12 *	Thomas Graf		<tgraf@suug.ch>
13 *	Ville Nuorvala		<vnuorval@tcs.hut.fi>
14 */
15
16#include <linux/config.h>
17#include <linux/netdevice.h>
18
19#include <net/fib_rules.h>
20#include <net/ipv6.h>
21#include <net/ip6_route.h>
22#include <net/netlink.h>
23
24struct fib6_rule
25{
26	struct fib_rule		common;
27	struct rt6key		src;
28	struct rt6key		dst;
29#ifdef CONFIG_IPV6_ROUTE_FWMARK
30	u32			fwmark;
31	u32			fwmask;
32#endif
33	u8			tclass;
34};
35
36static struct fib_rules_ops fib6_rules_ops;
37
38static struct fib6_rule main_rule = {
39	.common = {
40		.refcnt =	ATOMIC_INIT(2),
41		.pref =		0x7FFE,
42		.action =	FR_ACT_TO_TBL,
43		.table =	RT6_TABLE_MAIN,
44	},
45};
46
47static struct fib6_rule local_rule = {
48	.common = {
49		.refcnt =	ATOMIC_INIT(2),
50		.pref =		0,
51		.action =	FR_ACT_TO_TBL,
52		.table =	RT6_TABLE_LOCAL,
53		.flags =	FIB_RULE_PERMANENT,
54	},
55};
56
57static LIST_HEAD(fib6_rules);
58
59struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
60				   pol_lookup_t lookup)
61{
62	struct fib_lookup_arg arg = {
63		.lookup_ptr = lookup,
64	};
65
66	fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg);
67	if (arg.rule)
68		fib_rule_put(arg.rule);
69
70	if (arg.result)
71		return (struct dst_entry *) arg.result;
72
73	dst_hold(&ip6_null_entry.u.dst);
74	return &ip6_null_entry.u.dst;
75}
76
77static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
78			    int flags, struct fib_lookup_arg *arg)
79{
80	struct rt6_info *rt = NULL;
81	struct fib6_table *table;
82	pol_lookup_t lookup = arg->lookup_ptr;
83
84	switch (rule->action) {
85	case FR_ACT_TO_TBL:
86		break;
87	case FR_ACT_UNREACHABLE:
88		rt = &ip6_null_entry;
89		goto discard_pkt;
90	default:
91	case FR_ACT_BLACKHOLE:
92		rt = &ip6_blk_hole_entry;
93		goto discard_pkt;
94	case FR_ACT_PROHIBIT:
95		rt = &ip6_prohibit_entry;
96		goto discard_pkt;
97	}
98
99	table = fib6_get_table(rule->table);
100	if (table)
101		rt = lookup(table, flp, flags);
102
103	if (rt != &ip6_null_entry)
104		goto out;
105	dst_release(&rt->u.dst);
106	rt = NULL;
107	goto out;
108
109discard_pkt:
110	dst_hold(&rt->u.dst);
111out:
112	arg->result = rt;
113	return rt == NULL ? -EAGAIN : 0;
114}
115
116
117static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
118{
119	struct fib6_rule *r = (struct fib6_rule *) rule;
120
121	if (!ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
122		return 0;
123
124	if ((flags & RT6_LOOKUP_F_HAS_SADDR) &&
125	    !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
126		return 0;
127
128	if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
129		return 0;
130
131#ifdef CONFIG_IPV6_ROUTE_FWMARK
132	if ((r->fwmark ^ fl->fl6_fwmark) & r->fwmask)
133		return 0;
134#endif
135
136	return 1;
137}
138
139static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
140	[FRA_IFNAME]	= { .type = NLA_STRING },
141	[FRA_PRIORITY]	= { .type = NLA_U32 },
142	[FRA_SRC]	= { .minlen = sizeof(struct in6_addr) },
143	[FRA_DST]	= { .minlen = sizeof(struct in6_addr) },
144	[FRA_FWMARK]	= { .type = NLA_U32 },
145	[FRA_FWMASK]	= { .type = NLA_U32 },
146	[FRA_TABLE]	= { .type = NLA_U32 },
147};
148
149static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
150			       struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
151			       struct nlattr **tb)
152{
153	int err = -EINVAL;
154	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
155
156	if (frh->src_len > 128 || frh->dst_len > 128 ||
157	    (frh->tos & ~IPV6_FLOWINFO_MASK))
158		goto errout;
159
160	if (rule->action == FR_ACT_TO_TBL) {
161		if (rule->table == RT6_TABLE_UNSPEC)
162			goto errout;
163
164		if (fib6_new_table(rule->table) == NULL) {
165			err = -ENOBUFS;
166			goto errout;
167		}
168	}
169
170	if (tb[FRA_SRC])
171		nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
172			   sizeof(struct in6_addr));
173
174	if (tb[FRA_DST])
175		nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
176			   sizeof(struct in6_addr));
177
178#ifdef CONFIG_IPV6_ROUTE_FWMARK
179	if (tb[FRA_FWMARK]) {
180		rule6->fwmark = nla_get_u32(tb[FRA_FWMARK]);
181		if (rule6->fwmark) {
182			/*
183			 * if the mark value is non-zero,
184			 * all bits are compared by default
185			 * unless a mask is explicitly specified.
186			 */
187			rule6->fwmask = 0xFFFFFFFF;
188		}
189	}
190
191	if (tb[FRA_FWMASK])
192		rule6->fwmask = nla_get_u32(tb[FRA_FWMASK]);
193#endif
194
195	rule6->src.plen = frh->src_len;
196	rule6->dst.plen = frh->dst_len;
197	rule6->tclass = frh->tos;
198
199	err = 0;
200errout:
201	return err;
202}
203
204static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
205			     struct nlattr **tb)
206{
207	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
208
209	if (frh->src_len && (rule6->src.plen != frh->src_len))
210		return 0;
211
212	if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
213		return 0;
214
215	if (frh->tos && (rule6->tclass != frh->tos))
216		return 0;
217
218	if (tb[FRA_SRC] &&
219	    nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
220		return 0;
221
222	if (tb[FRA_DST] &&
223	    nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
224		return 0;
225
226#ifdef CONFIG_IPV6_ROUTE_FWMARK
227	if (tb[FRA_FWMARK] && (rule6->fwmark != nla_get_u32(tb[FRA_FWMARK])))
228		return 0;
229
230	if (tb[FRA_FWMASK] && (rule6->fwmask != nla_get_u32(tb[FRA_FWMASK])))
231		return 0;
232#endif
233
234	return 1;
235}
236
237static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
238			  struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
239{
240	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
241
242	frh->family = AF_INET6;
243	frh->dst_len = rule6->dst.plen;
244	frh->src_len = rule6->src.plen;
245	frh->tos = rule6->tclass;
246
247	if (rule6->dst.plen)
248		NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
249			&rule6->dst.addr);
250
251	if (rule6->src.plen)
252		NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
253			&rule6->src.addr);
254
255#ifdef CONFIG_IPV6_ROUTE_FWMARK
256	if (rule6->fwmark)
257		NLA_PUT_U32(skb, FRA_FWMARK, rule6->fwmark);
258
259	if (rule6->fwmask || rule6->fwmark)
260		NLA_PUT_U32(skb, FRA_FWMASK, rule6->fwmask);
261#endif
262
263	return 0;
264
265nla_put_failure:
266	return -ENOBUFS;
267}
268
269int fib6_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
270{
271	return fib_rules_dump(skb, cb, AF_INET6);
272}
273
274static u32 fib6_rule_default_pref(void)
275{
276	return 0x3FFF;
277}
278
279static struct fib_rules_ops fib6_rules_ops = {
280	.family			= AF_INET6,
281	.rule_size		= sizeof(struct fib6_rule),
282	.action			= fib6_rule_action,
283	.match			= fib6_rule_match,
284	.configure		= fib6_rule_configure,
285	.compare		= fib6_rule_compare,
286	.fill			= fib6_rule_fill,
287	.default_pref		= fib6_rule_default_pref,
288	.nlgroup		= RTNLGRP_IPV6_RULE,
289	.policy			= fib6_rule_policy,
290	.rules_list		= &fib6_rules,
291	.owner			= THIS_MODULE,
292};
293
294void __init fib6_rules_init(void)
295{
296	list_add_tail(&local_rule.common.list, &fib6_rules);
297	list_add_tail(&main_rule.common.list, &fib6_rules);
298
299	fib_rules_register(&fib6_rules_ops);
300}
301
302void fib6_rules_cleanup(void)
303{
304	fib_rules_unregister(&fib6_rules_ops);
305}
306