fib6_rules.c revision 038b0a6d8d32db934bba6a24e74e76e4e327a94f 
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/netdevice.h>
17
18#include <net/fib_rules.h>
19#include <net/ipv6.h>
20#include <net/ip6_route.h>
21#include <net/netlink.h>
22
23struct fib6_rule
24{
25	struct fib_rule		common;
26	struct rt6key		src;
27	struct rt6key		dst;
28#ifdef CONFIG_IPV6_ROUTE_FWMARK
29	u32			fwmark;
30	u32			fwmask;
31#endif
32	u8			tclass;
33};
34
35static struct fib_rules_ops fib6_rules_ops;
36
37static struct fib6_rule main_rule = {
38	.common = {
39		.refcnt =	ATOMIC_INIT(2),
40		.pref =		0x7FFE,
41		.action =	FR_ACT_TO_TBL,
42		.table =	RT6_TABLE_MAIN,
43	},
44};
45
46static struct fib6_rule local_rule = {
47	.common = {
48		.refcnt =	ATOMIC_INIT(2),
49		.pref =		0,
50		.action =	FR_ACT_TO_TBL,
51		.table =	RT6_TABLE_LOCAL,
52		.flags =	FIB_RULE_PERMANENT,
53	},
54};
55
56static LIST_HEAD(fib6_rules);
57
58struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
59				   pol_lookup_t lookup)
60{
61	struct fib_lookup_arg arg = {
62		.lookup_ptr = lookup,
63	};
64
65	fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg);
66	if (arg.rule)
67		fib_rule_put(arg.rule);
68
69	if (arg.result)
70		return (struct dst_entry *) arg.result;
71
72	dst_hold(&ip6_null_entry.u.dst);
73	return &ip6_null_entry.u.dst;
74}
75
76static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
77			    int flags, struct fib_lookup_arg *arg)
78{
79	struct rt6_info *rt = NULL;
80	struct fib6_table *table;
81	pol_lookup_t lookup = arg->lookup_ptr;
82
83	switch (rule->action) {
84	case FR_ACT_TO_TBL:
85		break;
86	case FR_ACT_UNREACHABLE:
87		rt = &ip6_null_entry;
88		goto discard_pkt;
89	default:
90	case FR_ACT_BLACKHOLE:
91		rt = &ip6_blk_hole_entry;
92		goto discard_pkt;
93	case FR_ACT_PROHIBIT:
94		rt = &ip6_prohibit_entry;
95		goto discard_pkt;
96	}
97
98	table = fib6_get_table(rule->table);
99	if (table)
100		rt = lookup(table, flp, flags);
101
102	if (rt != &ip6_null_entry)
103		goto out;
104	dst_release(&rt->u.dst);
105	rt = NULL;
106	goto out;
107
108discard_pkt:
109	dst_hold(&rt->u.dst);
110out:
111	arg->result = rt;
112	return rt == NULL ? -EAGAIN : 0;
113}
114
115
116static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
117{
118	struct fib6_rule *r = (struct fib6_rule *) rule;
119
120	if (!ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
121		return 0;
122
123	if ((flags & RT6_LOOKUP_F_HAS_SADDR) &&
124	    !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
125		return 0;
126
127	if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
128		return 0;
129
130#ifdef CONFIG_IPV6_ROUTE_FWMARK
131	if ((r->fwmark ^ fl->fl6_fwmark) & r->fwmask)
132		return 0;
133#endif
134
135	return 1;
136}
137
138static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
139	[FRA_IFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
140	[FRA_PRIORITY]	= { .type = NLA_U32 },
141	[FRA_SRC]	= { .len = sizeof(struct in6_addr) },
142	[FRA_DST]	= { .len = sizeof(struct in6_addr) },
143	[FRA_FWMARK]	= { .type = NLA_U32 },
144	[FRA_FWMASK]	= { .type = NLA_U32 },
145	[FRA_TABLE]	= { .type = NLA_U32 },
146};
147
148static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
149			       struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
150			       struct nlattr **tb)
151{
152	int err = -EINVAL;
153	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
154
155	if (frh->src_len > 128 || frh->dst_len > 128 ||
156	    (frh->tos & ~IPV6_FLOWINFO_MASK))
157		goto errout;
158
159	if (rule->action == FR_ACT_TO_TBL) {
160		if (rule->table == RT6_TABLE_UNSPEC)
161			goto errout;
162
163		if (fib6_new_table(rule->table) == NULL) {
164			err = -ENOBUFS;
165			goto errout;
166		}
167	}
168
169	if (tb[FRA_SRC])
170		nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
171			   sizeof(struct in6_addr));
172
173	if (tb[FRA_DST])
174		nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
175			   sizeof(struct in6_addr));
176
177#ifdef CONFIG_IPV6_ROUTE_FWMARK
178	if (tb[FRA_FWMARK]) {
179		rule6->fwmark = nla_get_u32(tb[FRA_FWMARK]);
180		if (rule6->fwmark) {
181			/*
182			 * if the mark value is non-zero,
183			 * all bits are compared by default
184			 * unless a mask is explicitly specified.
185			 */
186			rule6->fwmask = 0xFFFFFFFF;
187		}
188	}
189
190	if (tb[FRA_FWMASK])
191		rule6->fwmask = nla_get_u32(tb[FRA_FWMASK]);
192#endif
193
194	rule6->src.plen = frh->src_len;
195	rule6->dst.plen = frh->dst_len;
196	rule6->tclass = frh->tos;
197
198	err = 0;
199errout:
200	return err;
201}
202
203static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
204			     struct nlattr **tb)
205{
206	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
207
208	if (frh->src_len && (rule6->src.plen != frh->src_len))
209		return 0;
210
211	if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
212		return 0;
213
214	if (frh->tos && (rule6->tclass != frh->tos))
215		return 0;
216
217	if (tb[FRA_SRC] &&
218	    nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
219		return 0;
220
221	if (tb[FRA_DST] &&
222	    nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
223		return 0;
224
225#ifdef CONFIG_IPV6_ROUTE_FWMARK
226	if (tb[FRA_FWMARK] && (rule6->fwmark != nla_get_u32(tb[FRA_FWMARK])))
227		return 0;
228
229	if (tb[FRA_FWMASK] && (rule6->fwmask != nla_get_u32(tb[FRA_FWMASK])))
230		return 0;
231#endif
232
233	return 1;
234}
235
236static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
237			  struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
238{
239	struct fib6_rule *rule6 = (struct fib6_rule *) rule;
240
241	frh->family = AF_INET6;
242	frh->dst_len = rule6->dst.plen;
243	frh->src_len = rule6->src.plen;
244	frh->tos = rule6->tclass;
245
246	if (rule6->dst.plen)
247		NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
248			&rule6->dst.addr);
249
250	if (rule6->src.plen)
251		NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
252			&rule6->src.addr);
253
254#ifdef CONFIG_IPV6_ROUTE_FWMARK
255	if (rule6->fwmark)
256		NLA_PUT_U32(skb, FRA_FWMARK, rule6->fwmark);
257
258	if (rule6->fwmask || rule6->fwmark)
259		NLA_PUT_U32(skb, FRA_FWMASK, rule6->fwmask);
260#endif
261
262	return 0;
263
264nla_put_failure:
265	return -ENOBUFS;
266}
267
268int fib6_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
269{
270	return fib_rules_dump(skb, cb, AF_INET6);
271}
272
273static u32 fib6_rule_default_pref(void)
274{
275	return 0x3FFF;
276}
277
278static struct fib_rules_ops fib6_rules_ops = {
279	.family			= AF_INET6,
280	.rule_size		= sizeof(struct fib6_rule),
281	.action			= fib6_rule_action,
282	.match			= fib6_rule_match,
283	.configure		= fib6_rule_configure,
284	.compare		= fib6_rule_compare,
285	.fill			= fib6_rule_fill,
286	.default_pref		= fib6_rule_default_pref,
287	.nlgroup		= RTNLGRP_IPV6_RULE,
288	.policy			= fib6_rule_policy,
289	.rules_list		= &fib6_rules,
290	.owner			= THIS_MODULE,
291};
292
293void __init fib6_rules_init(void)
294{
295	list_add_tail(&local_rule.common.list, &fib6_rules);
296	list_add_tail(&main_rule.common.list, &fib6_rules);
297
298	fib_rules_register(&fib6_rules_ops);
299}
300
301void fib6_rules_cleanup(void)
302{
303	fib_rules_unregister(&fib6_rules_ops);
304}
305