[NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.
[linux-3.10.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(ip6_dst_idev(&rt->u.dst)->dev,
97                                                &flp->fl6_dst, srcprefs,
98                                                &saddr))
99                                 goto again;
100                         if (!ipv6_prefix_equal(&saddr, &r->src.addr,
101                                                r->src.plen))
102                                 goto again;
103                         ipv6_addr_copy(&flp->fl6_src, &saddr);
104                 }
105                 goto out;
106         }
107 again:
108         dst_release(&rt->u.dst);
109         rt = NULL;
110         goto out;
111
112 discard_pkt:
113         dst_hold(&rt->u.dst);
114 out:
115         arg->result = rt;
116         return rt == NULL ? -EAGAIN : 0;
117 }
118
119
120 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
121 {
122         struct fib6_rule *r = (struct fib6_rule *) rule;
123
124         if (r->dst.plen &&
125             !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
126                 return 0;
127
128         /*
129          * If FIB_RULE_FIND_SADDR is set and we do not have a
130          * source address for the traffic, we defer check for
131          * source address.
132          */
133         if (r->src.plen) {
134                 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
135                         if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
136                                                r->src.plen))
137                                 return 0;
138                 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
139                         return 0;
140         }
141
142         if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
143                 return 0;
144
145         return 1;
146 }
147
148 static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
149         FRA_GENERIC_POLICY,
150 };
151
152 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
153                                struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
154                                struct nlattr **tb)
155 {
156         int err = -EINVAL;
157         struct net *net = sock_net(skb->sk);
158         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
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(net, rule->table) == NULL) {
165                         err = -ENOBUFS;
166                         goto errout;
167                 }
168         }
169
170         if (frh->src_len)
171                 nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
172                            sizeof(struct in6_addr));
173
174         if (frh->dst_len)
175                 nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
176                            sizeof(struct in6_addr));
177
178         rule6->src.plen = frh->src_len;
179         rule6->dst.plen = frh->dst_len;
180         rule6->tclass = frh->tos;
181
182         err = 0;
183 errout:
184         return err;
185 }
186
187 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
188                              struct nlattr **tb)
189 {
190         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
191
192         if (frh->src_len && (rule6->src.plen != frh->src_len))
193                 return 0;
194
195         if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
196                 return 0;
197
198         if (frh->tos && (rule6->tclass != frh->tos))
199                 return 0;
200
201         if (frh->src_len &&
202             nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
203                 return 0;
204
205         if (frh->dst_len &&
206             nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
207                 return 0;
208
209         return 1;
210 }
211
212 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
213                           struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
214 {
215         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
216
217         frh->family = AF_INET6;
218         frh->dst_len = rule6->dst.plen;
219         frh->src_len = rule6->src.plen;
220         frh->tos = rule6->tclass;
221
222         if (rule6->dst.plen)
223                 NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
224                         &rule6->dst.addr);
225
226         if (rule6->src.plen)
227                 NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
228                         &rule6->src.addr);
229
230         return 0;
231
232 nla_put_failure:
233         return -ENOBUFS;
234 }
235
236 static u32 fib6_rule_default_pref(struct fib_rules_ops *ops)
237 {
238         return 0x3FFF;
239 }
240
241 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
242 {
243         return nla_total_size(16) /* dst */
244                + nla_total_size(16); /* src */
245 }
246
247 static struct fib_rules_ops fib6_rules_ops_template = {
248         .family                 = AF_INET6,
249         .rule_size              = sizeof(struct fib6_rule),
250         .addr_size              = sizeof(struct in6_addr),
251         .action                 = fib6_rule_action,
252         .match                  = fib6_rule_match,
253         .configure              = fib6_rule_configure,
254         .compare                = fib6_rule_compare,
255         .fill                   = fib6_rule_fill,
256         .default_pref           = fib6_rule_default_pref,
257         .nlmsg_payload          = fib6_rule_nlmsg_payload,
258         .nlgroup                = RTNLGRP_IPV6_RULE,
259         .policy                 = fib6_rule_policy,
260         .owner                  = THIS_MODULE,
261         .fro_net                = &init_net,
262 };
263
264 static int fib6_rules_net_init(struct net *net)
265 {
266         int err = -ENOMEM;
267
268         net->ipv6.fib6_rules_ops = kmemdup(&fib6_rules_ops_template,
269                                            sizeof(*net->ipv6.fib6_rules_ops),
270                                            GFP_KERNEL);
271         if (!net->ipv6.fib6_rules_ops)
272                 goto out;
273
274         net->ipv6.fib6_rules_ops->fro_net = net;
275         INIT_LIST_HEAD(&net->ipv6.fib6_rules_ops->rules_list);
276
277         err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
278                                    RT6_TABLE_LOCAL, FIB_RULE_PERMANENT);
279         if (err)
280                 goto out_fib6_rules_ops;
281
282         err = fib_default_rule_add(net->ipv6.fib6_rules_ops,
283                                    0x7FFE, RT6_TABLE_MAIN, 0);
284         if (err)
285                 goto out_fib6_default_rule_add;
286
287         err = fib_rules_register(net->ipv6.fib6_rules_ops);
288         if (err)
289                 goto out_fib6_default_rule_add;
290 out:
291         return err;
292
293 out_fib6_default_rule_add:
294         fib_rules_cleanup_ops(net->ipv6.fib6_rules_ops);
295 out_fib6_rules_ops:
296         kfree(net->ipv6.fib6_rules_ops);
297         goto out;
298 }
299
300 static void fib6_rules_net_exit(struct net *net)
301 {
302         fib_rules_unregister(net->ipv6.fib6_rules_ops);
303         kfree(net->ipv6.fib6_rules_ops);
304 }
305
306 static struct pernet_operations fib6_rules_net_ops = {
307         .init = fib6_rules_net_init,
308         .exit = fib6_rules_net_exit,
309 };
310
311 int __init fib6_rules_init(void)
312 {
313         return register_pernet_subsys(&fib6_rules_net_ops);
314 }
315
316
317 void fib6_rules_cleanup(void)
318 {
319         return unregister_pernet_subsys(&fib6_rules_net_ops);
320 }