34f5bfaddfc293f20e890be4c9acc4db193a4fe9
[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/config.h>
17 #include <linux/netdevice.h>
18
19 #include <net/fib_rules.h>
20 #include <net/ipv6.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 #ifdef CONFIG_IPV6_ROUTE_FWMARK
30         u32                     fwmark;
31         u32                     fwmask;
32 #endif
33         u8                      tclass;
34 };
35
36 static struct fib_rules_ops fib6_rules_ops;
37
38 static struct fib6_rule main_rule = {
39         .common = {
40                 .refcnt =       ATOMIC_INIT(2),
41                 .pref =         0x7FFE,
42                 .action =       FR_ACT_TO_TBL,
43                 .table =        RT6_TABLE_MAIN,
44         },
45 };
46
47 static struct fib6_rule local_rule = {
48         .common = {
49                 .refcnt =       ATOMIC_INIT(2),
50                 .pref =         0,
51                 .action =       FR_ACT_TO_TBL,
52                 .table =        RT6_TABLE_LOCAL,
53                 .flags =        FIB_RULE_PERMANENT,
54         },
55 };
56
57 static LIST_HEAD(fib6_rules);
58
59 struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
60                                    pol_lookup_t lookup)
61 {
62         struct fib_lookup_arg arg = {
63                 .lookup_ptr = lookup,
64         };
65
66         fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg);
67         if (arg.rule)
68                 fib_rule_put(arg.rule);
69
70         if (arg.result)
71                 return (struct dst_entry *) arg.result;
72
73         dst_hold(&ip6_null_entry.u.dst);
74         return &ip6_null_entry.u.dst;
75 }
76
77 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
78                             int flags, struct fib_lookup_arg *arg)
79 {
80         struct rt6_info *rt = NULL;
81         struct fib6_table *table;
82         pol_lookup_t lookup = arg->lookup_ptr;
83
84         switch (rule->action) {
85         case FR_ACT_TO_TBL:
86                 break;
87         case FR_ACT_UNREACHABLE:
88                 rt = &ip6_null_entry;
89                 goto discard_pkt;
90         default:
91         case FR_ACT_BLACKHOLE:
92                 rt = &ip6_blk_hole_entry;
93                 goto discard_pkt;
94         case FR_ACT_PROHIBIT:
95                 rt = &ip6_prohibit_entry;
96                 goto discard_pkt;
97         }
98
99         table = fib6_get_table(rule->table);
100         if (table)
101                 rt = lookup(table, flp, flags);
102
103         if (rt != &ip6_null_entry)
104                 goto out;
105         dst_release(&rt->u.dst);
106         rt = NULL;
107         goto out;
108
109 discard_pkt:
110         dst_hold(&rt->u.dst);
111 out:
112         arg->result = rt;
113         return rt == NULL ? -EAGAIN : 0;
114 }
115
116
117 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
118 {
119         struct fib6_rule *r = (struct fib6_rule *) rule;
120
121         if (!ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
122                 return 0;
123
124         if ((flags & RT6_LOOKUP_F_HAS_SADDR) &&
125             !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
126                 return 0;
127
128         if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
129                 return 0;
130
131 #ifdef CONFIG_IPV6_ROUTE_FWMARK
132         if ((r->fwmark ^ fl->fl6_fwmark) & r->fwmask)
133                 return 0;
134 #endif
135
136         return 1;
137 }
138
139 static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
140         [FRA_IFNAME]    = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
141         [FRA_PRIORITY]  = { .type = NLA_U32 },
142         [FRA_SRC]       = { .len = sizeof(struct in6_addr) },
143         [FRA_DST]       = { .len = sizeof(struct in6_addr) },
144         [FRA_FWMARK]    = { .type = NLA_U32 },
145         [FRA_FWMASK]    = { .type = NLA_U32 },
146         [FRA_TABLE]     = { .type = NLA_U32 },
147 };
148
149 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
150                                struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
151                                struct nlattr **tb)
152 {
153         int err = -EINVAL;
154         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
155
156         if (frh->src_len > 128 || frh->dst_len > 128 ||
157             (frh->tos & ~IPV6_FLOWINFO_MASK))
158                 goto errout;
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(rule->table) == NULL) {
165                         err = -ENOBUFS;
166                         goto errout;
167                 }
168         }
169
170         if (tb[FRA_SRC])
171                 nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
172                            sizeof(struct in6_addr));
173
174         if (tb[FRA_DST])
175                 nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
176                            sizeof(struct in6_addr));
177
178 #ifdef CONFIG_IPV6_ROUTE_FWMARK
179         if (tb[FRA_FWMARK]) {
180                 rule6->fwmark = nla_get_u32(tb[FRA_FWMARK]);
181                 if (rule6->fwmark) {
182                         /*
183                          * if the mark value is non-zero,
184                          * all bits are compared by default
185                          * unless a mask is explicitly specified.
186                          */
187                         rule6->fwmask = 0xFFFFFFFF;
188                 }
189         }
190
191         if (tb[FRA_FWMASK])
192                 rule6->fwmask = nla_get_u32(tb[FRA_FWMASK]);
193 #endif
194
195         rule6->src.plen = frh->src_len;
196         rule6->dst.plen = frh->dst_len;
197         rule6->tclass = frh->tos;
198
199         err = 0;
200 errout:
201         return err;
202 }
203
204 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
205                              struct nlattr **tb)
206 {
207         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
208
209         if (frh->src_len && (rule6->src.plen != frh->src_len))
210                 return 0;
211
212         if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
213                 return 0;
214
215         if (frh->tos && (rule6->tclass != frh->tos))
216                 return 0;
217
218         if (tb[FRA_SRC] &&
219             nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
220                 return 0;
221
222         if (tb[FRA_DST] &&
223             nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
224                 return 0;
225
226 #ifdef CONFIG_IPV6_ROUTE_FWMARK
227         if (tb[FRA_FWMARK] && (rule6->fwmark != nla_get_u32(tb[FRA_FWMARK])))
228                 return 0;
229
230         if (tb[FRA_FWMASK] && (rule6->fwmask != nla_get_u32(tb[FRA_FWMASK])))
231                 return 0;
232 #endif
233
234         return 1;
235 }
236
237 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
238                           struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
239 {
240         struct fib6_rule *rule6 = (struct fib6_rule *) rule;
241
242         frh->family = AF_INET6;
243         frh->dst_len = rule6->dst.plen;
244         frh->src_len = rule6->src.plen;
245         frh->tos = rule6->tclass;
246
247         if (rule6->dst.plen)
248                 NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
249                         &rule6->dst.addr);
250
251         if (rule6->src.plen)
252                 NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
253                         &rule6->src.addr);
254
255 #ifdef CONFIG_IPV6_ROUTE_FWMARK
256         if (rule6->fwmark)
257                 NLA_PUT_U32(skb, FRA_FWMARK, rule6->fwmark);
258
259         if (rule6->fwmask || rule6->fwmark)
260                 NLA_PUT_U32(skb, FRA_FWMASK, rule6->fwmask);
261 #endif
262
263         return 0;
264
265 nla_put_failure:
266         return -ENOBUFS;
267 }
268
269 int fib6_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
270 {
271         return fib_rules_dump(skb, cb, AF_INET6);
272 }
273
274 static u32 fib6_rule_default_pref(void)
275 {
276         return 0x3FFF;
277 }
278
279 static struct fib_rules_ops fib6_rules_ops = {
280         .family                 = AF_INET6,
281         .rule_size              = sizeof(struct fib6_rule),
282         .action                 = fib6_rule_action,
283         .match                  = fib6_rule_match,
284         .configure              = fib6_rule_configure,
285         .compare                = fib6_rule_compare,
286         .fill                   = fib6_rule_fill,
287         .default_pref           = fib6_rule_default_pref,
288         .nlgroup                = RTNLGRP_IPV6_RULE,
289         .policy                 = fib6_rule_policy,
290         .rules_list             = &fib6_rules,
291         .owner                  = THIS_MODULE,
292 };
293
294 void __init fib6_rules_init(void)
295 {
296         list_add_tail(&local_rule.common.list, &fib6_rules);
297         list_add_tail(&main_rule.common.list, &fib6_rules);
298
299         fib_rules_register(&fib6_rules_ops);
300 }
301
302 void fib6_rules_cleanup(void)
303 {
304         fib_rules_unregister(&fib6_rules_ops);
305 }