1
2
3
4
5
6
7
8
9
10
11
12
13#include <linux/netdevice.h>
14#include <linux/notifier.h>
15#include <linux/export.h>
16
17#include <net/fib_rules.h>
18#include <net/ipv6.h>
19#include <net/addrconf.h>
20#include <net/ip6_route.h>
21#include <net/netlink.h>
22
23struct fib6_rule {
24 struct fib_rule common;
25 struct rt6key src;
26 struct rt6key dst;
27 u8 tclass;
28};
29
30static bool fib6_rule_matchall(const struct fib_rule *rule)
31{
32 struct fib6_rule *r = container_of(rule, struct fib6_rule, common);
33
34 if (r->dst.plen || r->src.plen || r->tclass)
35 return false;
36 return fib_rule_matchall(rule);
37}
38
39bool fib6_rule_default(const struct fib_rule *rule)
40{
41 if (!fib6_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
42 rule->l3mdev)
43 return false;
44 if (rule->table != RT6_TABLE_LOCAL && rule->table != RT6_TABLE_MAIN)
45 return false;
46 return true;
47}
48EXPORT_SYMBOL_GPL(fib6_rule_default);
49
50int fib6_rules_dump(struct net *net, struct notifier_block *nb)
51{
52 return fib_rules_dump(net, nb, AF_INET6);
53}
54
55unsigned int fib6_rules_seq_read(struct net *net)
56{
57 return fib_rules_seq_read(net, AF_INET6);
58}
59
60
61int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
62 struct fib6_result *res, int flags)
63{
64 int err;
65
66 if (net->ipv6.fib6_has_custom_rules) {
67 struct fib_lookup_arg arg = {
68 .lookup_ptr = fib6_table_lookup,
69 .lookup_data = &oif,
70 .result = res,
71 .flags = FIB_LOOKUP_NOREF,
72 };
73
74 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
75
76 err = fib_rules_lookup(net->ipv6.fib6_rules_ops,
77 flowi6_to_flowi(fl6), flags, &arg);
78 } else {
79 err = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, oif,
80 fl6, res, flags);
81 if (err || res->f6i == net->ipv6.fib6_null_entry)
82 err = fib6_table_lookup(net, net->ipv6.fib6_main_tbl,
83 oif, fl6, res, flags);
84 }
85
86 return err;
87}
88
89struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
90 const struct sk_buff *skb,
91 int flags, pol_lookup_t lookup)
92{
93 if (net->ipv6.fib6_has_custom_rules) {
94 struct fib6_result res = {};
95 struct fib_lookup_arg arg = {
96 .lookup_ptr = lookup,
97 .lookup_data = skb,
98 .result = &res,
99 .flags = FIB_LOOKUP_NOREF,
100 };
101
102
103 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
104
105 fib_rules_lookup(net->ipv6.fib6_rules_ops,
106 flowi6_to_flowi(fl6), flags, &arg);
107
108 if (res.rt6)
109 return &res.rt6->dst;
110 } else {
111 struct rt6_info *rt;
112
113 rt = lookup(net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
114 if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
115 return &rt->dst;
116 ip6_rt_put_flags(rt, flags);
117 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
118 if (rt->dst.error != -EAGAIN)
119 return &rt->dst;
120 ip6_rt_put_flags(rt, flags);
121 }
122
123 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
124 dst_hold(&net->ipv6.ip6_null_entry->dst);
125 return &net->ipv6.ip6_null_entry->dst;
126}
127
128static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags,
129 struct flowi6 *flp6, const struct net_device *dev)
130{
131 struct fib6_rule *r = (struct fib6_rule *)rule;
132
133
134
135
136 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
137 r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
138 struct in6_addr saddr;
139
140 if (ipv6_dev_get_saddr(net, dev, &flp6->daddr,
141 rt6_flags2srcprefs(flags), &saddr))
142 return -EAGAIN;
143
144 if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen))
145 return -EAGAIN;
146
147 flp6->saddr = saddr;
148 }
149
150 return 0;
151}
152
153static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp,
154 int flags, struct fib_lookup_arg *arg)
155{
156 struct fib6_result *res = arg->result;
157 struct flowi6 *flp6 = &flp->u.ip6;
158 struct net *net = rule->fr_net;
159 struct fib6_table *table;
160 int err, *oif;
161 u32 tb_id;
162
163 switch (rule->action) {
164 case FR_ACT_TO_TBL:
165 break;
166 case FR_ACT_UNREACHABLE:
167 return -ENETUNREACH;
168 case FR_ACT_PROHIBIT:
169 return -EACCES;
170 case FR_ACT_BLACKHOLE:
171 default:
172 return -EINVAL;
173 }
174
175 tb_id = fib_rule_get_table(rule, arg);
176 table = fib6_get_table(net, tb_id);
177 if (!table)
178 return -EAGAIN;
179
180 oif = (int *)arg->lookup_data;
181 err = fib6_table_lookup(net, table, *oif, flp6, res, flags);
182 if (!err && res->f6i != net->ipv6.fib6_null_entry)
183 err = fib6_rule_saddr(net, rule, flags, flp6,
184 res->nh->fib_nh_dev);
185 else
186 err = -EAGAIN;
187
188 return err;
189}
190
191static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
192 int flags, struct fib_lookup_arg *arg)
193{
194 struct fib6_result *res = arg->result;
195 struct flowi6 *flp6 = &flp->u.ip6;
196 struct rt6_info *rt = NULL;
197 struct fib6_table *table;
198 struct net *net = rule->fr_net;
199 pol_lookup_t lookup = arg->lookup_ptr;
200 int err = 0;
201 u32 tb_id;
202
203 switch (rule->action) {
204 case FR_ACT_TO_TBL:
205 break;
206 case FR_ACT_UNREACHABLE:
207 err = -ENETUNREACH;
208 rt = net->ipv6.ip6_null_entry;
209 goto discard_pkt;
210 default:
211 case FR_ACT_BLACKHOLE:
212 err = -EINVAL;
213 rt = net->ipv6.ip6_blk_hole_entry;
214 goto discard_pkt;
215 case FR_ACT_PROHIBIT:
216 err = -EACCES;
217 rt = net->ipv6.ip6_prohibit_entry;
218 goto discard_pkt;
219 }
220
221 tb_id = fib_rule_get_table(rule, arg);
222 table = fib6_get_table(net, tb_id);
223 if (!table) {
224 err = -EAGAIN;
225 goto out;
226 }
227
228 rt = lookup(net, table, flp6, arg->lookup_data, flags);
229 if (rt != net->ipv6.ip6_null_entry) {
230 err = fib6_rule_saddr(net, rule, flags, flp6,
231 ip6_dst_idev(&rt->dst)->dev);
232
233 if (err == -EAGAIN)
234 goto again;
235
236 err = rt->dst.error;
237 if (err != -EAGAIN)
238 goto out;
239 }
240again:
241 ip6_rt_put_flags(rt, flags);
242 err = -EAGAIN;
243 rt = NULL;
244 goto out;
245
246discard_pkt:
247 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
248 dst_hold(&rt->dst);
249out:
250 res->rt6 = rt;
251 return err;
252}
253
254static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
255 int flags, struct fib_lookup_arg *arg)
256{
257 if (arg->lookup_ptr == fib6_table_lookup)
258 return fib6_rule_action_alt(rule, flp, flags, arg);
259
260 return __fib6_rule_action(rule, flp, flags, arg);
261}
262
263static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
264{
265 struct fib6_result *res = arg->result;
266 struct rt6_info *rt = res->rt6;
267 struct net_device *dev = NULL;
268
269 if (!rt)
270 return false;
271
272 if (rt->rt6i_idev)
273 dev = rt->rt6i_idev->dev;
274
275
276
277
278 if (rt->rt6i_dst.plen <= rule->suppress_prefixlen)
279 goto suppress_route;
280
281
282
283
284 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
285 goto suppress_route;
286
287 return false;
288
289suppress_route:
290 ip6_rt_put(rt);
291 return true;
292}
293
294static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
295{
296 struct fib6_rule *r = (struct fib6_rule *) rule;
297 struct flowi6 *fl6 = &fl->u.ip6;
298
299 if (r->dst.plen &&
300 !ipv6_prefix_equal(&fl6->daddr, &r->dst.addr, r->dst.plen))
301 return 0;
302
303
304
305
306
307
308 if (r->src.plen) {
309 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
310 if (!ipv6_prefix_equal(&fl6->saddr, &r->src.addr,
311 r->src.plen))
312 return 0;
313 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
314 return 0;
315 }
316
317 if (r->tclass && r->tclass != ip6_tclass(fl6->flowlabel))
318 return 0;
319
320 if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto))
321 return 0;
322
323 if (fib_rule_port_range_set(&rule->sport_range) &&
324 !fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport))
325 return 0;
326
327 if (fib_rule_port_range_set(&rule->dport_range) &&
328 !fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport))
329 return 0;
330
331 return 1;
332}
333
334static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
335 FRA_GENERIC_POLICY,
336};
337
338static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
339 struct fib_rule_hdr *frh,
340 struct nlattr **tb,
341 struct netlink_ext_ack *extack)
342{
343 int err = -EINVAL;
344 struct net *net = sock_net(skb->sk);
345 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
346
347 if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
348 if (rule->table == RT6_TABLE_UNSPEC) {
349 NL_SET_ERR_MSG(extack, "Invalid table");
350 goto errout;
351 }
352
353 if (fib6_new_table(net, rule->table) == NULL) {
354 err = -ENOBUFS;
355 goto errout;
356 }
357 }
358
359 if (frh->src_len)
360 rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]);
361
362 if (frh->dst_len)
363 rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]);
364
365 rule6->src.plen = frh->src_len;
366 rule6->dst.plen = frh->dst_len;
367 rule6->tclass = frh->tos;
368
369 if (fib_rule_requires_fldissect(rule))
370 net->ipv6.fib6_rules_require_fldissect++;
371
372 net->ipv6.fib6_has_custom_rules = true;
373 err = 0;
374errout:
375 return err;
376}
377
378static int fib6_rule_delete(struct fib_rule *rule)
379{
380 struct net *net = rule->fr_net;
381
382 if (net->ipv6.fib6_rules_require_fldissect &&
383 fib_rule_requires_fldissect(rule))
384 net->ipv6.fib6_rules_require_fldissect--;
385
386 return 0;
387}
388
389static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
390 struct nlattr **tb)
391{
392 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
393
394 if (frh->src_len && (rule6->src.plen != frh->src_len))
395 return 0;
396
397 if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
398 return 0;
399
400 if (frh->tos && (rule6->tclass != frh->tos))
401 return 0;
402
403 if (frh->src_len &&
404 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
405 return 0;
406
407 if (frh->dst_len &&
408 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
409 return 0;
410
411 return 1;
412}
413
414static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
415 struct fib_rule_hdr *frh)
416{
417 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
418
419 frh->dst_len = rule6->dst.plen;
420 frh->src_len = rule6->src.plen;
421 frh->tos = rule6->tclass;
422
423 if ((rule6->dst.plen &&
424 nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) ||
425 (rule6->src.plen &&
426 nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr)))
427 goto nla_put_failure;
428 return 0;
429
430nla_put_failure:
431 return -ENOBUFS;
432}
433
434static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
435{
436 return nla_total_size(16)
437 + nla_total_size(16);
438}
439
440static const struct fib_rules_ops __net_initconst fib6_rules_ops_template = {
441 .family = AF_INET6,
442 .rule_size = sizeof(struct fib6_rule),
443 .addr_size = sizeof(struct in6_addr),
444 .action = fib6_rule_action,
445 .match = fib6_rule_match,
446 .suppress = fib6_rule_suppress,
447 .configure = fib6_rule_configure,
448 .delete = fib6_rule_delete,
449 .compare = fib6_rule_compare,
450 .fill = fib6_rule_fill,
451 .nlmsg_payload = fib6_rule_nlmsg_payload,
452 .nlgroup = RTNLGRP_IPV6_RULE,
453 .policy = fib6_rule_policy,
454 .owner = THIS_MODULE,
455 .fro_net = &init_net,
456};
457
458static int __net_init fib6_rules_net_init(struct net *net)
459{
460 struct fib_rules_ops *ops;
461 int err = -ENOMEM;
462
463 ops = fib_rules_register(&fib6_rules_ops_template, net);
464 if (IS_ERR(ops))
465 return PTR_ERR(ops);
466
467 err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0);
468 if (err)
469 goto out_fib6_rules_ops;
470
471 err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0);
472 if (err)
473 goto out_fib6_rules_ops;
474
475 net->ipv6.fib6_rules_ops = ops;
476 net->ipv6.fib6_rules_require_fldissect = 0;
477out:
478 return err;
479
480out_fib6_rules_ops:
481 fib_rules_unregister(ops);
482 goto out;
483}
484
485static void __net_exit fib6_rules_net_exit(struct net *net)
486{
487 rtnl_lock();
488 fib_rules_unregister(net->ipv6.fib6_rules_ops);
489 rtnl_unlock();
490}
491
492static struct pernet_operations fib6_rules_net_ops = {
493 .init = fib6_rules_net_init,
494 .exit = fib6_rules_net_exit,
495};
496
497int __init fib6_rules_init(void)
498{
499 return register_pernet_subsys(&fib6_rules_net_ops);
500}
501
502
503void fib6_rules_cleanup(void)
504{
505 unregister_pernet_subsys(&fib6_rules_net_ops);
506}
507
