net: fib_rules: mark arguments to fib_rules_register const and __net_initdata
[linux-2.6.git] / 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 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
33                                    int flags, pol_lookup_t lookup)
34 {
35         struct fib_lookup_arg arg = {
36                 .lookup_ptr = lookup,
37         };
38
39         fib_rules_lookup(net->ipv6.fib6_rules_ops, fl, flags, &arg);
40         if (arg.rule)
41                 fib_rule_put(arg.rule);
42
43         if (arg.result)
44                 return arg.result;
45
46         dst_hold(&net->ipv6.ip6_null_entry->u.dst);
47         return &net->ipv6.ip6_null_entry->u.dst;
48 }
49
50 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
51                             int flags, struct fib_lookup_arg *arg)
52 {
53         struct rt6_info *rt = NULL;
54         struct fib6_table *table;
55         struct net *net = rule->fr_net;
56         pol_lookup_t lookup = arg->lookup_ptr;
57
58         switch (rule->action) {
59         case FR_ACT_TO_TBL:
60                 break;
61         case FR_ACT_UNREACHABLE:
62                 rt = net->ipv6.ip6_null_entry;
63                 goto discard_pkt;
64         default:
65         case FR_ACT_BLACKHOLE:
66                 rt = net->ipv6.ip6_blk_hole_entry;
67                 goto discard_pkt;
68         case FR_ACT_PROHIBIT:
69                 rt = net->ipv6.ip6_prohibit_entry;
70                 goto discard_pkt;
71         }
72
73         table = fib6_get_table(net, rule->table);
74         if (table)
75                 rt = lookup(net, table, flp, flags);
76
77         if (rt != net->ipv6.ip6_null_entry) {
78                 struct fib6_rule *r = (struct fib6_rule *)rule;
79
80                 /*
81                  * If we need to find a source address for this traffic,
82                  * we check the result if it meets requirement of the rule.
83                  */
84                 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
85                     r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
86                         struct in6_addr saddr;
87
88                         if (ipv6_dev_get_saddr(net,
89                                                ip6_dst_idev(&rt->u.dst)->dev,
90                                                &flp->fl6_dst,
91                                                rt6_flags2srcprefs(flags),
92                                                &saddr))
93                                 goto again;
94                         if (!ipv6_prefix_equal(&saddr, &r->src.addr,
95                                                r->src.plen))
96                                 goto again;
97                         ipv6_addr_copy(&flp->fl6_src, &saddr);
98                 }
99                 goto out;
100         }
101 again:
102         dst_release(&rt->u.dst);
103         rt = NULL;
104         goto out;
105
106 discard_pkt:
107         dst_hold(&rt->u.dst);
108 out:
109         arg->result = rt;
110         return rt == NULL ? -EAGAIN : 0;
111 }
112
113
114 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
115 {
116         struct fib6_rule *r = (struct fib6_rule *) rule;
117
118         if (r->dst.plen &&
119             !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
120                 return 0;
121
122         /*
123          * If FIB_RULE_FIND_SADDR is set and we do not have a
124          * source address for the traffic, we defer check for
125          * source address.
126          */
127         if (r->src.plen) {
128                 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
129                         if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
130                                                r->src.plen))
131                                 return 0;
132                 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
133                         return 0;
134         }
135
136         if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
137                 return 0;
138
139         return 1;
140 }
141
142 static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
143         FRA_GENERIC_POLICY,
144 };
145
146 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
147                                struct fib_rule_hdr *frh,
148                                struct nlattr **tb)
149 {
150         int err = -EINVAL;
151         struct net *net = sock_net(skb->sk);
152         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
153
154         if (rule->action == FR_ACT_TO_TBL) {
155                 if (rule->table == RT6_TABLE_UNSPEC)
156                         goto errout;
157
158                 if (fib6_new_table(net, rule->table) == NULL) {
159                         err = -ENOBUFS;
160                         goto errout;
161                 }
162         }
163
164         if (frh->src_len)
165                 nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
166                            sizeof(struct in6_addr));
167
168         if (frh->dst_len)
169                 nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
170                            sizeof(struct in6_addr));
171
172         rule6->src.plen = frh->src_len;
173         rule6->dst.plen = frh->dst_len;
174         rule6->tclass = frh->tos;
175
176         err = 0;
177 errout:
178         return err;
179 }
180
181 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
182                              struct nlattr **tb)
183 {
184         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
185
186         if (frh->src_len && (rule6->src.plen != frh->src_len))
187                 return 0;
188
189         if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
190                 return 0;
191
192         if (frh->tos && (rule6->tclass != frh->tos))
193                 return 0;
194
195         if (frh->src_len &&
196             nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
197                 return 0;
198
199         if (frh->dst_len &&
200             nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
201                 return 0;
202
203         return 1;
204 }
205
206 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
207                           struct fib_rule_hdr *frh)
208 {
209         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
210
211         frh->dst_len = rule6->dst.plen;
212         frh->src_len = rule6->src.plen;
213         frh->tos = rule6->tclass;
214
215         if (rule6->dst.plen)
216                 NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
217                         &rule6->dst.addr);
218
219         if (rule6->src.plen)
220                 NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
221                         &rule6->src.addr);
222
223         return 0;
224
225 nla_put_failure:
226         return -ENOBUFS;
227 }
228
229 static u32 fib6_rule_default_pref(struct fib_rules_ops *ops)
230 {
231         return 0x3FFF;
232 }
233
234 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
235 {
236         return nla_total_size(16) /* dst */
237                + nla_total_size(16); /* src */
238 }
239
240 static const struct fib_rules_ops __net_initdata fib6_rules_ops_template = {
241         .family                 = FIB_RULES_IPV6,
242         .rule_size              = sizeof(struct fib6_rule),
243         .addr_size              = sizeof(struct in6_addr),
244         .action                 = fib6_rule_action,
245         .match                  = fib6_rule_match,
246         .configure              = fib6_rule_configure,
247         .compare                = fib6_rule_compare,
248         .fill                   = fib6_rule_fill,
249         .default_pref           = fib6_rule_default_pref,
250         .nlmsg_payload          = fib6_rule_nlmsg_payload,
251         .nlgroup                = RTNLGRP_IPV6_RULE,
252         .policy                 = fib6_rule_policy,
253         .owner                  = THIS_MODULE,
254         .fro_net                = &init_net,
255 };
256
257 static int __net_init fib6_rules_net_init(struct net *net)
258 {
259         struct fib_rules_ops *ops;
260         int err = -ENOMEM;
261
262         ops = fib_rules_register(&fib6_rules_ops_template, net);
263         if (IS_ERR(ops))
264                 return PTR_ERR(ops);
265         net->ipv6.fib6_rules_ops = ops;
266
267
268         err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
269                                    RT6_TABLE_LOCAL, 0);
270         if (err)
271                 goto out_fib6_rules_ops;
272
273         err = fib_default_rule_add(net->ipv6.fib6_rules_ops,
274                                    0x7FFE, RT6_TABLE_MAIN, 0);
275         if (err)
276                 goto out_fib6_rules_ops;
277
278 out:
279         return err;
280
281 out_fib6_rules_ops:
282         fib_rules_unregister(ops);
283         goto out;
284 }
285
286 static void __net_exit fib6_rules_net_exit(struct net *net)
287 {
288         fib_rules_unregister(net->ipv6.fib6_rules_ops);
289 }
290
291 static struct pernet_operations fib6_rules_net_ops = {
292         .init = fib6_rules_net_init,
293         .exit = fib6_rules_net_exit,
294 };
295
296 int __init fib6_rules_init(void)
297 {
298         return register_pernet_subsys(&fib6_rules_net_ops);
299 }
300
301
302 void fib6_rules_cleanup(void)
303 {
304         unregister_pernet_subsys(&fib6_rules_net_ops);
305 }