Merge master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / net / ipv6 / fib6_rules.c
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/addrconf.h>
21 #include <net/ip6_route.h>
22 #include <net/netlink.h>
23
24 struct fib6_rule
25 {
26         struct fib_rule         common;
27         struct rt6key           src;
28         struct rt6key           dst;
29         u8                      tclass;
30 };
31
32 static struct fib_rules_ops fib6_rules_ops;
33
34 static struct fib6_rule main_rule = {
35         .common = {
36                 .refcnt =       ATOMIC_INIT(2),
37                 .pref =         0x7FFE,
38                 .action =       FR_ACT_TO_TBL,
39                 .table =        RT6_TABLE_MAIN,
40         },
41 };
42
43 static struct fib6_rule local_rule = {
44         .common = {
45                 .refcnt =       ATOMIC_INIT(2),
46                 .pref =         0,
47                 .action =       FR_ACT_TO_TBL,
48                 .table =        RT6_TABLE_LOCAL,
49                 .flags =        FIB_RULE_PERMANENT,
50         },
51 };
52
53 struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
54                                    pol_lookup_t lookup)
55 {
56         struct fib_lookup_arg arg = {
57                 .lookup_ptr = lookup,
58         };
59
60         fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg);
61         if (arg.rule)
62                 fib_rule_put(arg.rule);
63
64         if (arg.result)
65                 return arg.result;
66
67         dst_hold(&ip6_null_entry.u.dst);
68         return &ip6_null_entry.u.dst;
69 }
70
71 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
72                             int flags, struct fib_lookup_arg *arg)
73 {
74         struct rt6_info *rt = NULL;
75         struct fib6_table *table;
76         pol_lookup_t lookup = arg->lookup_ptr;
77
78         switch (rule->action) {
79         case FR_ACT_TO_TBL:
80                 break;
81         case FR_ACT_UNREACHABLE:
82                 rt = &ip6_null_entry;
83                 goto discard_pkt;
84         default:
85         case FR_ACT_BLACKHOLE:
86                 rt = &ip6_blk_hole_entry;
87                 goto discard_pkt;
88         case FR_ACT_PROHIBIT:
89                 rt = &ip6_prohibit_entry;
90                 goto discard_pkt;
91         }
92
93         table = fib6_get_table(rule->table);
94         if (table)
95                 rt = lookup(table, flp, flags);
96
97         if (rt != &ip6_null_entry) {
98                 struct fib6_rule *r = (struct fib6_rule *)rule;
99
100                 /*
101                  * If we need to find a source address for this traffic,
102                  * we check the result if it meets requirement of the rule.
103                  */
104                 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
105                     r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
106                         struct in6_addr saddr;
107                         if (ipv6_get_saddr(&rt->u.dst, &flp->fl6_dst,
108                                            &saddr))
109                                 goto again;
110                         if (!ipv6_prefix_equal(&saddr, &r->src.addr,
111                                                r->src.plen))
112                                 goto again;
113                         ipv6_addr_copy(&flp->fl6_src, &saddr);
114                 }
115                 goto out;
116         }
117 again:
118         dst_release(&rt->u.dst);
119         rt = NULL;
120         goto out;
121
122 discard_pkt:
123         dst_hold(&rt->u.dst);
124 out:
125         arg->result = rt;
126         return rt == NULL ? -EAGAIN : 0;
127 }
128
129
130 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
131 {
132         struct fib6_rule *r = (struct fib6_rule *) rule;
133
134         if (r->dst.plen &&
135             !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
136                 return 0;
137
138         /*
139          * If FIB_RULE_FIND_SADDR is set and we do not have a
140          * source address for the traffic, we defer check for
141          * source address.
142          */
143         if (r->src.plen) {
144                 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
145                         if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
146                                                r->src.plen))
147                                 return 0;
148                 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
149                         return 0;
150         }
151
152         if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
153                 return 0;
154
155         return 1;
156 }
157
158 static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
159         FRA_GENERIC_POLICY,
160 };
161
162 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
163                                struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
164                                struct nlattr **tb)
165 {
166         int err = -EINVAL;
167         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
168
169         if (rule->action == FR_ACT_TO_TBL) {
170                 if (rule->table == RT6_TABLE_UNSPEC)
171                         goto errout;
172
173                 if (fib6_new_table(rule->table) == NULL) {
174                         err = -ENOBUFS;
175                         goto errout;
176                 }
177         }
178
179         if (frh->src_len)
180                 nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
181                            sizeof(struct in6_addr));
182
183         if (frh->dst_len)
184                 nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
185                            sizeof(struct in6_addr));
186
187         rule6->src.plen = frh->src_len;
188         rule6->dst.plen = frh->dst_len;
189         rule6->tclass = frh->tos;
190
191         err = 0;
192 errout:
193         return err;
194 }
195
196 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
197                              struct nlattr **tb)
198 {
199         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
200
201         if (frh->src_len && (rule6->src.plen != frh->src_len))
202                 return 0;
203
204         if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
205                 return 0;
206
207         if (frh->tos && (rule6->tclass != frh->tos))
208                 return 0;
209
210         if (frh->src_len &&
211             nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
212                 return 0;
213
214         if (frh->dst_len &&
215             nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
216                 return 0;
217
218         return 1;
219 }
220
221 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
222                           struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
223 {
224         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
225
226         frh->family = AF_INET6;
227         frh->dst_len = rule6->dst.plen;
228         frh->src_len = rule6->src.plen;
229         frh->tos = rule6->tclass;
230
231         if (rule6->dst.plen)
232                 NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
233                         &rule6->dst.addr);
234
235         if (rule6->src.plen)
236                 NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
237                         &rule6->src.addr);
238
239         return 0;
240
241 nla_put_failure:
242         return -ENOBUFS;
243 }
244
245 static u32 fib6_rule_default_pref(void)
246 {
247         return 0x3FFF;
248 }
249
250 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
251 {
252         return nla_total_size(16) /* dst */
253                + nla_total_size(16); /* src */
254 }
255
256 static struct fib_rules_ops fib6_rules_ops = {
257         .family                 = AF_INET6,
258         .rule_size              = sizeof(struct fib6_rule),
259         .addr_size              = sizeof(struct in6_addr),
260         .action                 = fib6_rule_action,
261         .match                  = fib6_rule_match,
262         .configure              = fib6_rule_configure,
263         .compare                = fib6_rule_compare,
264         .fill                   = fib6_rule_fill,
265         .default_pref           = fib6_rule_default_pref,
266         .nlmsg_payload          = fib6_rule_nlmsg_payload,
267         .nlgroup                = RTNLGRP_IPV6_RULE,
268         .policy                 = fib6_rule_policy,
269         .rules_list             = LIST_HEAD_INIT(fib6_rules_ops.rules_list),
270         .owner                  = THIS_MODULE,
271 };
272
273 void __init fib6_rules_init(void)
274 {
275         list_add_tail(&local_rule.common.list, &fib6_rules_ops.rules_list);
276         list_add_tail(&main_rule.common.list, &fib6_rules_ops.rules_list);
277
278         fib_rules_register(&fib6_rules_ops);
279 }
280
281 void fib6_rules_cleanup(void)
282 {
283         fib_rules_unregister(&fib6_rules_ops);
284 }