Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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                         unsigned int srcprefs = 0;
88
89                         if (flags & RT6_LOOKUP_F_SRCPREF_TMP)
90                                 srcprefs |= IPV6_PREFER_SRC_TMP;
91                         if (flags & RT6_LOOKUP_F_SRCPREF_PUBLIC)
92                                 srcprefs |= IPV6_PREFER_SRC_PUBLIC;
93                         if (flags & RT6_LOOKUP_F_SRCPREF_COA)
94                                 srcprefs |= IPV6_PREFER_SRC_COA;
95
96                         if (ipv6_dev_get_saddr(net,
97                                                ip6_dst_idev(&rt->u.dst)->dev,
98                                                &flp->fl6_dst, srcprefs,
99                                                &saddr))
100                                 goto again;
101                         if (!ipv6_prefix_equal(&saddr, &r->src.addr,
102                                                r->src.plen))
103                                 goto again;
104                         ipv6_addr_copy(&flp->fl6_src, &saddr);
105                 }
106                 goto out;
107         }
108 again:
109         dst_release(&rt->u.dst);
110         rt = NULL;
111         goto out;
112
113 discard_pkt:
114         dst_hold(&rt->u.dst);
115 out:
116         arg->result = rt;
117         return rt == NULL ? -EAGAIN : 0;
118 }
119
120
121 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
122 {
123         struct fib6_rule *r = (struct fib6_rule *) rule;
124
125         if (r->dst.plen &&
126             !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
127                 return 0;
128
129         /*
130          * If FIB_RULE_FIND_SADDR is set and we do not have a
131          * source address for the traffic, we defer check for
132          * source address.
133          */
134         if (r->src.plen) {
135                 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
136                         if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
137                                                r->src.plen))
138                                 return 0;
139                 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
140                         return 0;
141         }
142
143         if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
144                 return 0;
145
146         return 1;
147 }
148
149 static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
150         FRA_GENERIC_POLICY,
151 };
152
153 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
154                                struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
155                                struct nlattr **tb)
156 {
157         int err = -EINVAL;
158         struct net *net = sock_net(skb->sk);
159         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
160
161         if (rule->action == FR_ACT_TO_TBL) {
162                 if (rule->table == RT6_TABLE_UNSPEC)
163                         goto errout;
164
165                 if (fib6_new_table(net, rule->table) == NULL) {
166                         err = -ENOBUFS;
167                         goto errout;
168                 }
169         }
170
171         if (frh->src_len)
172                 nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
173                            sizeof(struct in6_addr));
174
175         if (frh->dst_len)
176                 nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
177                            sizeof(struct in6_addr));
178
179         rule6->src.plen = frh->src_len;
180         rule6->dst.plen = frh->dst_len;
181         rule6->tclass = frh->tos;
182
183         err = 0;
184 errout:
185         return err;
186 }
187
188 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
189                              struct nlattr **tb)
190 {
191         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
192
193         if (frh->src_len && (rule6->src.plen != frh->src_len))
194                 return 0;
195
196         if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
197                 return 0;
198
199         if (frh->tos && (rule6->tclass != frh->tos))
200                 return 0;
201
202         if (frh->src_len &&
203             nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
204                 return 0;
205
206         if (frh->dst_len &&
207             nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
208                 return 0;
209
210         return 1;
211 }
212
213 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
214                           struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
215 {
216         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
217
218         frh->family = AF_INET6;
219         frh->dst_len = rule6->dst.plen;
220         frh->src_len = rule6->src.plen;
221         frh->tos = rule6->tclass;
222
223         if (rule6->dst.plen)
224                 NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
225                         &rule6->dst.addr);
226
227         if (rule6->src.plen)
228                 NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
229                         &rule6->src.addr);
230
231         return 0;
232
233 nla_put_failure:
234         return -ENOBUFS;
235 }
236
237 static u32 fib6_rule_default_pref(struct fib_rules_ops *ops)
238 {
239         return 0x3FFF;
240 }
241
242 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
243 {
244         return nla_total_size(16) /* dst */
245                + nla_total_size(16); /* src */
246 }
247
248 static struct fib_rules_ops fib6_rules_ops_template = {
249         .family                 = AF_INET6,
250         .rule_size              = sizeof(struct fib6_rule),
251         .addr_size              = sizeof(struct in6_addr),
252         .action                 = fib6_rule_action,
253         .match                  = fib6_rule_match,
254         .configure              = fib6_rule_configure,
255         .compare                = fib6_rule_compare,
256         .fill                   = fib6_rule_fill,
257         .default_pref           = fib6_rule_default_pref,
258         .nlmsg_payload          = fib6_rule_nlmsg_payload,
259         .nlgroup                = RTNLGRP_IPV6_RULE,
260         .policy                 = fib6_rule_policy,
261         .owner                  = THIS_MODULE,
262         .fro_net                = &init_net,
263 };
264
265 static int fib6_rules_net_init(struct net *net)
266 {
267         int err = -ENOMEM;
268
269         net->ipv6.fib6_rules_ops = kmemdup(&fib6_rules_ops_template,
270                                            sizeof(*net->ipv6.fib6_rules_ops),
271                                            GFP_KERNEL);
272         if (!net->ipv6.fib6_rules_ops)
273                 goto out;
274
275         net->ipv6.fib6_rules_ops->fro_net = net;
276         INIT_LIST_HEAD(&net->ipv6.fib6_rules_ops->rules_list);
277
278         err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
279                                    RT6_TABLE_LOCAL, FIB_RULE_PERMANENT);
280         if (err)
281                 goto out_fib6_rules_ops;
282
283         err = fib_default_rule_add(net->ipv6.fib6_rules_ops,
284                                    0x7FFE, RT6_TABLE_MAIN, 0);
285         if (err)
286                 goto out_fib6_default_rule_add;
287
288         err = fib_rules_register(net->ipv6.fib6_rules_ops);
289         if (err)
290                 goto out_fib6_default_rule_add;
291 out:
292         return err;
293
294 out_fib6_default_rule_add:
295         fib_rules_cleanup_ops(net->ipv6.fib6_rules_ops);
296 out_fib6_rules_ops:
297         kfree(net->ipv6.fib6_rules_ops);
298         goto out;
299 }
300
301 static void fib6_rules_net_exit(struct net *net)
302 {
303         fib_rules_unregister(net->ipv6.fib6_rules_ops);
304         kfree(net->ipv6.fib6_rules_ops);
305 }
306
307 static struct pernet_operations fib6_rules_net_ops = {
308         .init = fib6_rules_net_init,
309         .exit = fib6_rules_net_exit,
310 };
311
312 int __init fib6_rules_init(void)
313 {
314         return register_pernet_subsys(&fib6_rules_net_ops);
315 }
316
317
318 void fib6_rules_cleanup(void)
319 {
320         unregister_pernet_subsys(&fib6_rules_net_ops);
321 }