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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#include <linux/notifier.h>
18#include <linux/export.h>
19
20#include <net/fib_rules.h>
21#include <net/ipv6.h>
22#include <net/addrconf.h>
23#include <net/ip6_route.h>
24#include <net/netlink.h>
25
26struct fib6_rule {
27 struct fib_rule common;
28 struct rt6key src;
29 struct rt6key dst;
30 u8 tclass;
31};
32
33static bool fib6_rule_matchall(const struct fib_rule *rule)
34{
35 struct fib6_rule *r = container_of(rule, struct fib6_rule, common);
36
37 if (r->dst.plen || r->src.plen || r->tclass)
38 return false;
39 return fib_rule_matchall(rule);
40}
41
42bool fib6_rule_default(const struct fib_rule *rule)
43{
44 if (!fib6_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
45 rule->l3mdev)
46 return false;
47 if (rule->table != RT6_TABLE_LOCAL && rule->table != RT6_TABLE_MAIN)
48 return false;
49 return true;
50}
51EXPORT_SYMBOL_GPL(fib6_rule_default);
52
53int fib6_rules_dump(struct net *net, struct notifier_block *nb)
54{
55 return fib_rules_dump(net, nb, AF_INET6);
56}
57
58unsigned int fib6_rules_seq_read(struct net *net)
59{
60 return fib_rules_seq_read(net, AF_INET6);
61}
62
63struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
64 const struct sk_buff *skb,
65 int flags, pol_lookup_t lookup)
66{
67 if (net->ipv6.fib6_has_custom_rules) {
68 struct fib_lookup_arg arg = {
69 .lookup_ptr = lookup,
70 .lookup_data = skb,
71 .flags = FIB_LOOKUP_NOREF,
72 };
73
74 /* update flow if oif or iif point to device enslaved to l3mdev */
75 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
76
77 fib_rules_lookup(net->ipv6.fib6_rules_ops,
78 flowi6_to_flowi(fl6), flags, &arg);
79
80 if (arg.result)
81 return arg.result;
82 } else {
83 struct rt6_info *rt;
84
85 rt = lookup(net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
86 if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
87 return &rt->dst;
88 ip6_rt_put(rt);
89 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
90 if (rt->dst.error != -EAGAIN)
91 return &rt->dst;
92 ip6_rt_put(rt);
93 }
94
95 dst_hold(&net->ipv6.ip6_null_entry->dst);
96 return &net->ipv6.ip6_null_entry->dst;
97}
98
99static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
100 int flags, struct fib_lookup_arg *arg)
101{
102 struct flowi6 *flp6 = &flp->u.ip6;
103 struct rt6_info *rt = NULL;
104 struct fib6_table *table;
105 struct net *net = rule->fr_net;
106 pol_lookup_t lookup = arg->lookup_ptr;
107 int err = 0;
108 u32 tb_id;
109
110 switch (rule->action) {
111 case FR_ACT_TO_TBL:
112 break;
113 case FR_ACT_UNREACHABLE:
114 err = -ENETUNREACH;
115 rt = net->ipv6.ip6_null_entry;
116 goto discard_pkt;
117 default:
118 case FR_ACT_BLACKHOLE:
119 err = -EINVAL;
120 rt = net->ipv6.ip6_blk_hole_entry;
121 goto discard_pkt;
122 case FR_ACT_PROHIBIT:
123 err = -EACCES;
124 rt = net->ipv6.ip6_prohibit_entry;
125 goto discard_pkt;
126 }
127
128 tb_id = fib_rule_get_table(rule, arg);
129 table = fib6_get_table(net, tb_id);
130 if (!table) {
131 err = -EAGAIN;
132 goto out;
133 }
134
135 rt = lookup(net, table, flp6, arg->lookup_data, flags);
136 if (rt != net->ipv6.ip6_null_entry) {
137 struct fib6_rule *r = (struct fib6_rule *)rule;
138
139 /*
140 * If we need to find a source address for this traffic,
141 * we check the result if it meets requirement of the rule.
142 */
143 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
144 r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
145 struct in6_addr saddr;
146
147 if (ipv6_dev_get_saddr(net,
148 ip6_dst_idev(&rt->dst)->dev,
149 &flp6->daddr,
150 rt6_flags2srcprefs(flags),
151 &saddr))
152 goto again;
153 if (!ipv6_prefix_equal(&saddr, &r->src.addr,
154 r->src.plen))
155 goto again;
156 flp6->saddr = saddr;
157 }
158 err = rt->dst.error;
159 if (err != -EAGAIN)
160 goto out;
161 }
162again:
163 ip6_rt_put(rt);
164 err = -EAGAIN;
165 rt = NULL;
166 goto out;
167
168discard_pkt:
169 dst_hold(&rt->dst);
170out:
171 arg->result = rt;
172 return err;
173}
174
175static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
176{
177 struct rt6_info *rt = (struct rt6_info *) arg->result;
178 struct net_device *dev = NULL;
179
180 if (rt->rt6i_idev)
181 dev = rt->rt6i_idev->dev;
182
183 /* do not accept result if the route does
184 * not meet the required prefix length
185 */
186 if (rt->rt6i_dst.plen <= rule->suppress_prefixlen)
187 goto suppress_route;
188
189 /* do not accept result if the route uses a device
190 * belonging to a forbidden interface group
191 */
192 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
193 goto suppress_route;
194
195 return false;
196
197suppress_route:
198 ip6_rt_put(rt);
199 return true;
200}
201
202static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
203{
204 struct fib6_rule *r = (struct fib6_rule *) rule;
205 struct flowi6 *fl6 = &fl->u.ip6;
206
207 if (r->dst.plen &&
208 !ipv6_prefix_equal(&fl6->daddr, &r->dst.addr, r->dst.plen))
209 return 0;
210
211 /*
212 * If FIB_RULE_FIND_SADDR is set and we do not have a
213 * source address for the traffic, we defer check for
214 * source address.
215 */
216 if (r->src.plen) {
217 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
218 if (!ipv6_prefix_equal(&fl6->saddr, &r->src.addr,
219 r->src.plen))
220 return 0;
221 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
222 return 0;
223 }
224
225 if (r->tclass && r->tclass != ip6_tclass(fl6->flowlabel))
226 return 0;
227
228 if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto))
229 return 0;
230
231 if (fib_rule_port_range_set(&rule->sport_range) &&
232 !fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport))
233 return 0;
234
235 if (fib_rule_port_range_set(&rule->dport_range) &&
236 !fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport))
237 return 0;
238
239 return 1;
240}
241
242static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
243 FRA_GENERIC_POLICY,
244};
245
246static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
247 struct fib_rule_hdr *frh,
248 struct nlattr **tb)
249{
250 int err = -EINVAL;
251 struct net *net = sock_net(skb->sk);
252 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
253
254 if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
255 if (rule->table == RT6_TABLE_UNSPEC)
256 goto errout;
257
258 if (fib6_new_table(net, rule->table) == NULL) {
259 err = -ENOBUFS;
260 goto errout;
261 }
262 }
263
264 if (frh->src_len)
265 rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]);
266
267 if (frh->dst_len)
268 rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]);
269
270 rule6->src.plen = frh->src_len;
271 rule6->dst.plen = frh->dst_len;
272 rule6->tclass = frh->tos;
273
274 if (fib_rule_requires_fldissect(rule))
275 net->ipv6.fib6_rules_require_fldissect++;
276
277 net->ipv6.fib6_has_custom_rules = true;
278 err = 0;
279errout:
280 return err;
281}
282
283static int fib6_rule_delete(struct fib_rule *rule)
284{
285 struct net *net = rule->fr_net;
286
287 if (net->ipv6.fib6_rules_require_fldissect &&
288 fib_rule_requires_fldissect(rule))
289 net->ipv6.fib6_rules_require_fldissect--;
290
291 return 0;
292}
293
294static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
295 struct nlattr **tb)
296{
297 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
298
299 if (frh->src_len && (rule6->src.plen != frh->src_len))
300 return 0;
301
302 if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
303 return 0;
304
305 if (frh->tos && (rule6->tclass != frh->tos))
306 return 0;
307
308 if (frh->src_len &&
309 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
310 return 0;
311
312 if (frh->dst_len &&
313 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
314 return 0;
315
316 return 1;
317}
318
319static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
320 struct fib_rule_hdr *frh)
321{
322 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
323
324 frh->dst_len = rule6->dst.plen;
325 frh->src_len = rule6->src.plen;
326 frh->tos = rule6->tclass;
327
328 if ((rule6->dst.plen &&
329 nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) ||
330 (rule6->src.plen &&
331 nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr)))
332 goto nla_put_failure;
333 return 0;
334
335nla_put_failure:
336 return -ENOBUFS;
337}
338
339static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
340{
341 return nla_total_size(16) /* dst */
342 + nla_total_size(16); /* src */
343}
344
345static const struct fib_rules_ops __net_initconst fib6_rules_ops_template = {
346 .family = AF_INET6,
347 .rule_size = sizeof(struct fib6_rule),
348 .addr_size = sizeof(struct in6_addr),
349 .action = fib6_rule_action,
350 .match = fib6_rule_match,
351 .suppress = fib6_rule_suppress,
352 .configure = fib6_rule_configure,
353 .delete = fib6_rule_delete,
354 .compare = fib6_rule_compare,
355 .fill = fib6_rule_fill,
356 .nlmsg_payload = fib6_rule_nlmsg_payload,
357 .nlgroup = RTNLGRP_IPV6_RULE,
358 .policy = fib6_rule_policy,
359 .owner = THIS_MODULE,
360 .fro_net = &init_net,
361};
362
363static int __net_init fib6_rules_net_init(struct net *net)
364{
365 struct fib_rules_ops *ops;
366 int err = -ENOMEM;
367
368 ops = fib_rules_register(&fib6_rules_ops_template, net);
369 if (IS_ERR(ops))
370 return PTR_ERR(ops);
371
372 err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0);
373 if (err)
374 goto out_fib6_rules_ops;
375
376 err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0);
377 if (err)
378 goto out_fib6_rules_ops;
379
380 net->ipv6.fib6_rules_ops = ops;
381 net->ipv6.fib6_rules_require_fldissect = 0;
382out:
383 return err;
384
385out_fib6_rules_ops:
386 fib_rules_unregister(ops);
387 goto out;
388}
389
390static void __net_exit fib6_rules_net_exit(struct net *net)
391{
392 rtnl_lock();
393 fib_rules_unregister(net->ipv6.fib6_rules_ops);
394 rtnl_unlock();
395}
396
397static struct pernet_operations fib6_rules_net_ops = {
398 .init = fib6_rules_net_init,
399 .exit = fib6_rules_net_exit,
400};
401
402int __init fib6_rules_init(void)
403{
404 return register_pernet_subsys(&fib6_rules_net_ops);
405}
406
407
408void fib6_rules_cleanup(void)
409{
410 unregister_pernet_subsys(&fib6_rules_net_ops);
411}
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#include <linux/export.h>
18
19#include <net/fib_rules.h>
20#include <net/ipv6.h>
21#include <net/addrconf.h>
22#include <net/ip6_route.h>
23#include <net/netlink.h>
24
25struct fib6_rule {
26 struct fib_rule common;
27 struct rt6key src;
28 struct rt6key dst;
29 u8 tclass;
30};
31
32struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
33 int flags, pol_lookup_t lookup)
34{
35 struct fib_lookup_arg arg = {
36 .lookup_ptr = lookup,
37 .flags = FIB_LOOKUP_NOREF,
38 };
39
40 fib_rules_lookup(net->ipv6.fib6_rules_ops,
41 flowi6_to_flowi(fl6), flags, &arg);
42
43 if (arg.result)
44 return arg.result;
45
46 dst_hold(&net->ipv6.ip6_null_entry->dst);
47 return &net->ipv6.ip6_null_entry->dst;
48}
49
50static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
51 int flags, struct fib_lookup_arg *arg)
52{
53 struct flowi6 *flp6 = &flp->u.ip6;
54 struct rt6_info *rt = NULL;
55 struct fib6_table *table;
56 struct net *net = rule->fr_net;
57 pol_lookup_t lookup = arg->lookup_ptr;
58
59 switch (rule->action) {
60 case FR_ACT_TO_TBL:
61 break;
62 case FR_ACT_UNREACHABLE:
63 rt = net->ipv6.ip6_null_entry;
64 goto discard_pkt;
65 default:
66 case FR_ACT_BLACKHOLE:
67 rt = net->ipv6.ip6_blk_hole_entry;
68 goto discard_pkt;
69 case FR_ACT_PROHIBIT:
70 rt = net->ipv6.ip6_prohibit_entry;
71 goto discard_pkt;
72 }
73
74 table = fib6_get_table(net, rule->table);
75 if (table)
76 rt = lookup(net, table, flp6, flags);
77
78 if (rt != net->ipv6.ip6_null_entry) {
79 struct fib6_rule *r = (struct fib6_rule *)rule;
80
81 /*
82 * If we need to find a source address for this traffic,
83 * we check the result if it meets requirement of the rule.
84 */
85 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
86 r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
87 struct in6_addr saddr;
88
89 if (ipv6_dev_get_saddr(net,
90 ip6_dst_idev(&rt->dst)->dev,
91 &flp6->daddr,
92 rt6_flags2srcprefs(flags),
93 &saddr))
94 goto again;
95 if (!ipv6_prefix_equal(&saddr, &r->src.addr,
96 r->src.plen))
97 goto again;
98 flp6->saddr = saddr;
99 }
100 goto out;
101 }
102again:
103 dst_release(&rt->dst);
104 rt = NULL;
105 goto out;
106
107discard_pkt:
108 dst_hold(&rt->dst);
109out:
110 arg->result = rt;
111 return rt == NULL ? -EAGAIN : 0;
112}
113
114
115static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
116{
117 struct fib6_rule *r = (struct fib6_rule *) rule;
118 struct flowi6 *fl6 = &fl->u.ip6;
119
120 if (r->dst.plen &&
121 !ipv6_prefix_equal(&fl6->daddr, &r->dst.addr, r->dst.plen))
122 return 0;
123
124 /*
125 * If FIB_RULE_FIND_SADDR is set and we do not have a
126 * source address for the traffic, we defer check for
127 * source address.
128 */
129 if (r->src.plen) {
130 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
131 if (!ipv6_prefix_equal(&fl6->saddr, &r->src.addr,
132 r->src.plen))
133 return 0;
134 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
135 return 0;
136 }
137
138 if (r->tclass && r->tclass != ((ntohl(fl6->flowlabel) >> 20) & 0xff))
139 return 0;
140
141 return 1;
142}
143
144static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
145 FRA_GENERIC_POLICY,
146};
147
148static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
149 struct fib_rule_hdr *frh,
150 struct nlattr **tb)
151{
152 int err = -EINVAL;
153 struct net *net = sock_net(skb->sk);
154 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
155
156 if (rule->action == FR_ACT_TO_TBL) {
157 if (rule->table == RT6_TABLE_UNSPEC)
158 goto errout;
159
160 if (fib6_new_table(net, rule->table) == NULL) {
161 err = -ENOBUFS;
162 goto errout;
163 }
164 }
165
166 if (frh->src_len)
167 nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
168 sizeof(struct in6_addr));
169
170 if (frh->dst_len)
171 nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
172 sizeof(struct in6_addr));
173
174 rule6->src.plen = frh->src_len;
175 rule6->dst.plen = frh->dst_len;
176 rule6->tclass = frh->tos;
177
178 err = 0;
179errout:
180 return err;
181}
182
183static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
184 struct nlattr **tb)
185{
186 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
187
188 if (frh->src_len && (rule6->src.plen != frh->src_len))
189 return 0;
190
191 if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
192 return 0;
193
194 if (frh->tos && (rule6->tclass != frh->tos))
195 return 0;
196
197 if (frh->src_len &&
198 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
199 return 0;
200
201 if (frh->dst_len &&
202 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
203 return 0;
204
205 return 1;
206}
207
208static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
209 struct fib_rule_hdr *frh)
210{
211 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
212
213 frh->dst_len = rule6->dst.plen;
214 frh->src_len = rule6->src.plen;
215 frh->tos = rule6->tclass;
216
217 if ((rule6->dst.plen &&
218 nla_put(skb, FRA_DST, sizeof(struct in6_addr),
219 &rule6->dst.addr)) ||
220 (rule6->src.plen &&
221 nla_put(skb, FRA_SRC, sizeof(struct in6_addr),
222 &rule6->src.addr)))
223 goto nla_put_failure;
224 return 0;
225
226nla_put_failure:
227 return -ENOBUFS;
228}
229
230static u32 fib6_rule_default_pref(struct fib_rules_ops *ops)
231{
232 return 0x3FFF;
233}
234
235static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
236{
237 return nla_total_size(16) /* dst */
238 + nla_total_size(16); /* src */
239}
240
241static const struct fib_rules_ops __net_initdata fib6_rules_ops_template = {
242 .family = AF_INET6,
243 .rule_size = sizeof(struct fib6_rule),
244 .addr_size = sizeof(struct in6_addr),
245 .action = fib6_rule_action,
246 .match = fib6_rule_match,
247 .configure = fib6_rule_configure,
248 .compare = fib6_rule_compare,
249 .fill = fib6_rule_fill,
250 .default_pref = fib6_rule_default_pref,
251 .nlmsg_payload = fib6_rule_nlmsg_payload,
252 .nlgroup = RTNLGRP_IPV6_RULE,
253 .policy = fib6_rule_policy,
254 .owner = THIS_MODULE,
255 .fro_net = &init_net,
256};
257
258static int __net_init fib6_rules_net_init(struct net *net)
259{
260 struct fib_rules_ops *ops;
261 int err = -ENOMEM;
262
263 ops = fib_rules_register(&fib6_rules_ops_template, net);
264 if (IS_ERR(ops))
265 return PTR_ERR(ops);
266 net->ipv6.fib6_rules_ops = ops;
267
268
269 err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
270 RT6_TABLE_LOCAL, 0);
271 if (err)
272 goto out_fib6_rules_ops;
273
274 err = fib_default_rule_add(net->ipv6.fib6_rules_ops,
275 0x7FFE, RT6_TABLE_MAIN, 0);
276 if (err)
277 goto out_fib6_rules_ops;
278
279out:
280 return err;
281
282out_fib6_rules_ops:
283 fib_rules_unregister(ops);
284 goto out;
285}
286
287static void __net_exit fib6_rules_net_exit(struct net *net)
288{
289 fib_rules_unregister(net->ipv6.fib6_rules_ops);
290}
291
292static struct pernet_operations fib6_rules_net_ops = {
293 .init = fib6_rules_net_init,
294 .exit = fib6_rules_net_exit,
295};
296
297int __init fib6_rules_init(void)
298{
299 return register_pernet_subsys(&fib6_rules_net_ops);
300}
301
302
303void fib6_rules_cleanup(void)
304{
305 unregister_pernet_subsys(&fib6_rules_net_ops);
306}