1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * net/core/fib_rules.c Generic Routing Rules
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 */
7
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/list.h>
12 #include <linux/module.h>
13 #include <net/net_namespace.h>
14 #include <net/sock.h>
15 #include <net/fib_rules.h>
16 #include <net/ip_tunnels.h>
17 #include <linux/indirect_call_wrapper.h>
18
19 #if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES)
20 #ifdef CONFIG_IP_MULTIPLE_TABLES
21 #define INDIRECT_CALL_MT(f, f2, f1, ...) \
22 INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__)
23 #else
24 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
25 #endif
26 #elif defined(CONFIG_IP_MULTIPLE_TABLES)
27 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
28 #else
29 #define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__)
30 #endif
31
32 static const struct fib_kuid_range fib_kuid_range_unset = {
33 KUIDT_INIT(0),
34 KUIDT_INIT(~0),
35 };
36
37 bool fib_rule_matchall(const struct fib_rule *rule)
38 {
39 if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
40 rule->flags)
41 return false;
42 if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
43 return false;
44 if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
45 !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
46 return false;
47 if (fib_rule_port_range_set(&rule->sport_range))
48 return false;
49 if (fib_rule_port_range_set(&rule->dport_range))
50 return false;
51 return true;
52 }
53 EXPORT_SYMBOL_GPL(fib_rule_matchall);
54
55 int fib_default_rule_add(struct fib_rules_ops *ops,
56 u32 pref, u32 table, u32 flags)
57 {
58 struct fib_rule *r;
59
60 r = kzalloc(ops->rule_size, GFP_KERNEL);
61 if (r == NULL)
62 return -ENOMEM;
63
64 refcount_set(&r->refcnt, 1);
65 r->action = FR_ACT_TO_TBL;
66 r->pref = pref;
67 r->table = table;
68 r->flags = flags;
69 r->proto = RTPROT_KERNEL;
70 r->fr_net = ops->fro_net;
71 r->uid_range = fib_kuid_range_unset;
72
73 r->suppress_prefixlen = -1;
74 r->suppress_ifgroup = -1;
75
76 /* The lock is not required here, the list in unreacheable
77 * at the moment this function is called */
78 list_add_tail(&r->list, &ops->rules_list);
79 return 0;
80 }
81 EXPORT_SYMBOL(fib_default_rule_add);
82
83 static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
84 {
85 struct list_head *pos;
86 struct fib_rule *rule;
87
88 if (!list_empty(&ops->rules_list)) {
89 pos = ops->rules_list.next;
90 if (pos->next != &ops->rules_list) {
91 rule = list_entry(pos->next, struct fib_rule, list);
92 if (rule->pref)
93 return rule->pref - 1;
94 }
95 }
96
97 return 0;
98 }
99
100 static void notify_rule_change(int event, struct fib_rule *rule,
101 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
102 u32 pid);
103
104 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
105 {
106 struct fib_rules_ops *ops;
107
108 rcu_read_lock();
109 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
110 if (ops->family == family) {
111 if (!try_module_get(ops->owner))
112 ops = NULL;
113 rcu_read_unlock();
114 return ops;
115 }
116 }
117 rcu_read_unlock();
118
119 return NULL;
120 }
121
122 static void rules_ops_put(struct fib_rules_ops *ops)
123 {
124 if (ops)
125 module_put(ops->owner);
126 }
127
128 static void flush_route_cache(struct fib_rules_ops *ops)
129 {
130 if (ops->flush_cache)
131 ops->flush_cache(ops);
132 }
133
134 static int __fib_rules_register(struct fib_rules_ops *ops)
135 {
136 int err = -EEXIST;
137 struct fib_rules_ops *o;
138 struct net *net;
139
140 net = ops->fro_net;
141
142 if (ops->rule_size < sizeof(struct fib_rule))
143 return -EINVAL;
144
145 if (ops->match == NULL || ops->configure == NULL ||
146 ops->compare == NULL || ops->fill == NULL ||
147 ops->action == NULL)
148 return -EINVAL;
149
150 spin_lock(&net->rules_mod_lock);
151 list_for_each_entry(o, &net->rules_ops, list)
152 if (ops->family == o->family)
153 goto errout;
154
155 list_add_tail_rcu(&ops->list, &net->rules_ops);
156 err = 0;
157 errout:
158 spin_unlock(&net->rules_mod_lock);
159
160 return err;
161 }
162
163 struct fib_rules_ops *
164 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
165 {
166 struct fib_rules_ops *ops;
167 int err;
168
169 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
170 if (ops == NULL)
171 return ERR_PTR(-ENOMEM);
172
173 INIT_LIST_HEAD(&ops->rules_list);
174 ops->fro_net = net;
175
176 err = __fib_rules_register(ops);
177 if (err) {
178 kfree(ops);
179 ops = ERR_PTR(err);
180 }
181
182 return ops;
183 }
184 EXPORT_SYMBOL_GPL(fib_rules_register);
185
186 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
187 {
188 struct fib_rule *rule, *tmp;
189
190 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
191 list_del_rcu(&rule->list);
192 if (ops->delete)
193 ops->delete(rule);
194 fib_rule_put(rule);
195 }
196 }
197
198 void fib_rules_unregister(struct fib_rules_ops *ops)
199 {
200 struct net *net = ops->fro_net;
201
202 spin_lock(&net->rules_mod_lock);
203 list_del_rcu(&ops->list);
204 spin_unlock(&net->rules_mod_lock);
205
206 fib_rules_cleanup_ops(ops);
207 kfree_rcu(ops, rcu);
208 }
209 EXPORT_SYMBOL_GPL(fib_rules_unregister);
210
211 static int uid_range_set(struct fib_kuid_range *range)
212 {
213 return uid_valid(range->start) && uid_valid(range->end);
214 }
215
216 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
217 {
218 struct fib_rule_uid_range *in;
219 struct fib_kuid_range out;
220
221 in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
222
223 out.start = make_kuid(current_user_ns(), in->start);
224 out.end = make_kuid(current_user_ns(), in->end);
225
226 return out;
227 }
228
229 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
230 {
231 struct fib_rule_uid_range out = {
232 from_kuid_munged(current_user_ns(), range->start),
233 from_kuid_munged(current_user_ns(), range->end)
234 };
235
236 return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
237 }
238
239 static int nla_get_port_range(struct nlattr *pattr,
240 struct fib_rule_port_range *port_range)
241 {
242 const struct fib_rule_port_range *pr = nla_data(pattr);
243
244 if (!fib_rule_port_range_valid(pr))
245 return -EINVAL;
246
247 port_range->start = pr->start;
248 port_range->end = pr->end;
249
250 return 0;
251 }
252
253 static int nla_put_port_range(struct sk_buff *skb, int attrtype,
254 struct fib_rule_port_range *range)
255 {
256 return nla_put(skb, attrtype, sizeof(*range), range);
257 }
258
259 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
260 struct flowi *fl, int flags,
261 struct fib_lookup_arg *arg)
262 {
263 int ret = 0;
264
265 if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
266 goto out;
267
268 if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
269 goto out;
270
271 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
272 goto out;
273
274 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
275 goto out;
276
277 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
278 goto out;
279
280 if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
281 uid_gt(fl->flowi_uid, rule->uid_range.end))
282 goto out;
283
284 ret = INDIRECT_CALL_MT(ops->match,
285 fib6_rule_match,
286 fib4_rule_match,
287 rule, fl, flags);
288 out:
289 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
290 }
291
292 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
293 int flags, struct fib_lookup_arg *arg)
294 {
295 struct fib_rule *rule;
296 int err;
297
298 rcu_read_lock();
299
300 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
301 jumped:
302 if (!fib_rule_match(rule, ops, fl, flags, arg))
303 continue;
304
305 if (rule->action == FR_ACT_GOTO) {
306 struct fib_rule *target;
307
308 target = rcu_dereference(rule->ctarget);
309 if (target == NULL) {
310 continue;
311 } else {
312 rule = target;
313 goto jumped;
314 }
315 } else if (rule->action == FR_ACT_NOP)
316 continue;
317 else
318 err = INDIRECT_CALL_MT(ops->action,
319 fib6_rule_action,
320 fib4_rule_action,
321 rule, fl, flags, arg);
322
323 if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress,
324 fib6_rule_suppress,
325 fib4_rule_suppress,
326 rule, arg))
327 continue;
328
329 if (err != -EAGAIN) {
330 if ((arg->flags & FIB_LOOKUP_NOREF) ||
331 likely(refcount_inc_not_zero(&rule->refcnt))) {
332 arg->rule = rule;
333 goto out;
334 }
335 break;
336 }
337 }
338
339 err = -ESRCH;
340 out:
341 rcu_read_unlock();
342
343 return err;
344 }
345 EXPORT_SYMBOL_GPL(fib_rules_lookup);
346
347 static int call_fib_rule_notifier(struct notifier_block *nb,
348 enum fib_event_type event_type,
349 struct fib_rule *rule, int family,
350 struct netlink_ext_ack *extack)
351 {
352 struct fib_rule_notifier_info info = {
353 .info.family = family,
354 .info.extack = extack,
355 .rule = rule,
356 };
357
358 return call_fib_notifier(nb, event_type, &info.info);
359 }
360
361 static int call_fib_rule_notifiers(struct net *net,
362 enum fib_event_type event_type,
363 struct fib_rule *rule,
364 struct fib_rules_ops *ops,
365 struct netlink_ext_ack *extack)
366 {
367 struct fib_rule_notifier_info info = {
368 .info.family = ops->family,
369 .info.extack = extack,
370 .rule = rule,
371 };
372
373 ops->fib_rules_seq++;
374 return call_fib_notifiers(net, event_type, &info.info);
375 }
376
377 /* Called with rcu_read_lock() */
378 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
379 struct netlink_ext_ack *extack)
380 {
381 struct fib_rules_ops *ops;
382 struct fib_rule *rule;
383 int err = 0;
384
385 ops = lookup_rules_ops(net, family);
386 if (!ops)
387 return -EAFNOSUPPORT;
388 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
389 err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD,
390 rule, family, extack);
391 if (err)
392 break;
393 }
394 rules_ops_put(ops);
395
396 return err;
397 }
398 EXPORT_SYMBOL_GPL(fib_rules_dump);
399
400 unsigned int fib_rules_seq_read(struct net *net, int family)
401 {
402 unsigned int fib_rules_seq;
403 struct fib_rules_ops *ops;
404
405 ASSERT_RTNL();
406
407 ops = lookup_rules_ops(net, family);
408 if (!ops)
409 return 0;
410 fib_rules_seq = ops->fib_rules_seq;
411 rules_ops_put(ops);
412
413 return fib_rules_seq;
414 }
415 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
416
417 static struct fib_rule *rule_find(struct fib_rules_ops *ops,
418 struct fib_rule_hdr *frh,
419 struct nlattr **tb,
420 struct fib_rule *rule,
421 bool user_priority)
422 {
423 struct fib_rule *r;
424
425 list_for_each_entry(r, &ops->rules_list, list) {
426 if (rule->action && r->action != rule->action)
427 continue;
428
429 if (rule->table && r->table != rule->table)
430 continue;
431
432 if (user_priority && r->pref != rule->pref)
433 continue;
434
435 if (rule->iifname[0] &&
436 memcmp(r->iifname, rule->iifname, IFNAMSIZ))
437 continue;
438
439 if (rule->oifname[0] &&
440 memcmp(r->oifname, rule->oifname, IFNAMSIZ))
441 continue;
442
443 if (rule->mark && r->mark != rule->mark)
444 continue;
445
446 if (rule->suppress_ifgroup != -1 &&
447 r->suppress_ifgroup != rule->suppress_ifgroup)
448 continue;
449
450 if (rule->suppress_prefixlen != -1 &&
451 r->suppress_prefixlen != rule->suppress_prefixlen)
452 continue;
453
454 if (rule->mark_mask && r->mark_mask != rule->mark_mask)
455 continue;
456
457 if (rule->tun_id && r->tun_id != rule->tun_id)
458 continue;
459
460 if (r->fr_net != rule->fr_net)
461 continue;
462
463 if (rule->l3mdev && r->l3mdev != rule->l3mdev)
464 continue;
465
466 if (uid_range_set(&rule->uid_range) &&
467 (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
468 !uid_eq(r->uid_range.end, rule->uid_range.end)))
469 continue;
470
471 if (rule->ip_proto && r->ip_proto != rule->ip_proto)
472 continue;
473
474 if (rule->proto && r->proto != rule->proto)
475 continue;
476
477 if (fib_rule_port_range_set(&rule->sport_range) &&
478 !fib_rule_port_range_compare(&r->sport_range,
479 &rule->sport_range))
480 continue;
481
482 if (fib_rule_port_range_set(&rule->dport_range) &&
483 !fib_rule_port_range_compare(&r->dport_range,
484 &rule->dport_range))
485 continue;
486
487 if (!ops->compare(r, frh, tb))
488 continue;
489 return r;
490 }
491
492 return NULL;
493 }
494
495 #ifdef CONFIG_NET_L3_MASTER_DEV
496 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
497 struct netlink_ext_ack *extack)
498 {
499 nlrule->l3mdev = nla_get_u8(nla);
500 if (nlrule->l3mdev != 1) {
501 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
502 return -1;
503 }
504
505 return 0;
506 }
507 #else
508 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
509 struct netlink_ext_ack *extack)
510 {
511 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
512 return -1;
513 }
514 #endif
515
516 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
517 struct netlink_ext_ack *extack,
518 struct fib_rules_ops *ops,
519 struct nlattr *tb[],
520 struct fib_rule **rule,
521 bool *user_priority)
522 {
523 struct net *net = sock_net(skb->sk);
524 struct fib_rule_hdr *frh = nlmsg_data(nlh);
525 struct fib_rule *nlrule = NULL;
526 int err = -EINVAL;
527
528 if (frh->src_len)
529 if (!tb[FRA_SRC] ||
530 frh->src_len > (ops->addr_size * 8) ||
531 nla_len(tb[FRA_SRC]) != ops->addr_size) {
532 NL_SET_ERR_MSG(extack, "Invalid source address");
533 goto errout;
534 }
535
536 if (frh->dst_len)
537 if (!tb[FRA_DST] ||
538 frh->dst_len > (ops->addr_size * 8) ||
539 nla_len(tb[FRA_DST]) != ops->addr_size) {
540 NL_SET_ERR_MSG(extack, "Invalid dst address");
541 goto errout;
542 }
543
544 nlrule = kzalloc(ops->rule_size, GFP_KERNEL);
545 if (!nlrule) {
546 err = -ENOMEM;
547 goto errout;
548 }
549 refcount_set(&nlrule->refcnt, 1);
550 nlrule->fr_net = net;
551
552 if (tb[FRA_PRIORITY]) {
553 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
554 *user_priority = true;
555 } else {
556 nlrule->pref = fib_default_rule_pref(ops);
557 }
558
559 nlrule->proto = tb[FRA_PROTOCOL] ?
560 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
561
562 if (tb[FRA_IIFNAME]) {
563 struct net_device *dev;
564
565 nlrule->iifindex = -1;
566 nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
567 dev = __dev_get_by_name(net, nlrule->iifname);
568 if (dev)
569 nlrule->iifindex = dev->ifindex;
570 }
571
572 if (tb[FRA_OIFNAME]) {
573 struct net_device *dev;
574
575 nlrule->oifindex = -1;
576 nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
577 dev = __dev_get_by_name(net, nlrule->oifname);
578 if (dev)
579 nlrule->oifindex = dev->ifindex;
580 }
581
582 if (tb[FRA_FWMARK]) {
583 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
584 if (nlrule->mark)
585 /* compatibility: if the mark value is non-zero all bits
586 * are compared unless a mask is explicitly specified.
587 */
588 nlrule->mark_mask = 0xFFFFFFFF;
589 }
590
591 if (tb[FRA_FWMASK])
592 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
593
594 if (tb[FRA_TUN_ID])
595 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
596
597 err = -EINVAL;
598 if (tb[FRA_L3MDEV] &&
599 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
600 goto errout_free;
601
602 nlrule->action = frh->action;
603 nlrule->flags = frh->flags;
604 nlrule->table = frh_get_table(frh, tb);
605 if (tb[FRA_SUPPRESS_PREFIXLEN])
606 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
607 else
608 nlrule->suppress_prefixlen = -1;
609
610 if (tb[FRA_SUPPRESS_IFGROUP])
611 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
612 else
613 nlrule->suppress_ifgroup = -1;
614
615 if (tb[FRA_GOTO]) {
616 if (nlrule->action != FR_ACT_GOTO) {
617 NL_SET_ERR_MSG(extack, "Unexpected goto");
618 goto errout_free;
619 }
620
621 nlrule->target = nla_get_u32(tb[FRA_GOTO]);
622 /* Backward jumps are prohibited to avoid endless loops */
623 if (nlrule->target <= nlrule->pref) {
624 NL_SET_ERR_MSG(extack, "Backward goto not supported");
625 goto errout_free;
626 }
627 } else if (nlrule->action == FR_ACT_GOTO) {
628 NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
629 goto errout_free;
630 }
631
632 if (nlrule->l3mdev && nlrule->table) {
633 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
634 goto errout_free;
635 }
636
637 if (tb[FRA_UID_RANGE]) {
638 if (current_user_ns() != net->user_ns) {
639 err = -EPERM;
640 NL_SET_ERR_MSG(extack, "No permission to set uid");
641 goto errout_free;
642 }
643
644 nlrule->uid_range = nla_get_kuid_range(tb);
645
646 if (!uid_range_set(&nlrule->uid_range) ||
647 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
648 NL_SET_ERR_MSG(extack, "Invalid uid range");
649 goto errout_free;
650 }
651 } else {
652 nlrule->uid_range = fib_kuid_range_unset;
653 }
654
655 if (tb[FRA_IP_PROTO])
656 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
657
658 if (tb[FRA_SPORT_RANGE]) {
659 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
660 &nlrule->sport_range);
661 if (err) {
662 NL_SET_ERR_MSG(extack, "Invalid sport range");
663 goto errout_free;
664 }
665 }
666
667 if (tb[FRA_DPORT_RANGE]) {
668 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
669 &nlrule->dport_range);
670 if (err) {
671 NL_SET_ERR_MSG(extack, "Invalid dport range");
672 goto errout_free;
673 }
674 }
675
676 *rule = nlrule;
677
678 return 0;
679
680 errout_free:
681 kfree(nlrule);
682 errout:
683 return err;
684 }
685
686 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
687 struct nlattr **tb, struct fib_rule *rule)
688 {
689 struct fib_rule *r;
690
691 list_for_each_entry(r, &ops->rules_list, list) {
692 if (r->action != rule->action)
693 continue;
694
695 if (r->table != rule->table)
696 continue;
697
698 if (r->pref != rule->pref)
699 continue;
700
701 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
702 continue;
703
704 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
705 continue;
706
707 if (r->mark != rule->mark)
708 continue;
709
710 if (r->suppress_ifgroup != rule->suppress_ifgroup)
711 continue;
712
713 if (r->suppress_prefixlen != rule->suppress_prefixlen)
714 continue;
715
716 if (r->mark_mask != rule->mark_mask)
717 continue;
718
719 if (r->tun_id != rule->tun_id)
720 continue;
721
722 if (r->fr_net != rule->fr_net)
723 continue;
724
725 if (r->l3mdev != rule->l3mdev)
726 continue;
727
728 if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
729 !uid_eq(r->uid_range.end, rule->uid_range.end))
730 continue;
731
732 if (r->ip_proto != rule->ip_proto)
733 continue;
734
735 if (r->proto != rule->proto)
736 continue;
737
738 if (!fib_rule_port_range_compare(&r->sport_range,
739 &rule->sport_range))
740 continue;
741
742 if (!fib_rule_port_range_compare(&r->dport_range,
743 &rule->dport_range))
744 continue;
745
746 if (!ops->compare(r, frh, tb))
747 continue;
748 return 1;
749 }
750 return 0;
751 }
752
753 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
754 struct netlink_ext_ack *extack)
755 {
756 struct net *net = sock_net(skb->sk);
757 struct fib_rule_hdr *frh = nlmsg_data(nlh);
758 struct fib_rules_ops *ops = NULL;
759 struct fib_rule *rule = NULL, *r, *last = NULL;
760 struct nlattr *tb[FRA_MAX + 1];
761 int err = -EINVAL, unresolved = 0;
762 bool user_priority = false;
763
764 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
765 NL_SET_ERR_MSG(extack, "Invalid msg length");
766 goto errout;
767 }
768
769 ops = lookup_rules_ops(net, frh->family);
770 if (!ops) {
771 err = -EAFNOSUPPORT;
772 NL_SET_ERR_MSG(extack, "Rule family not supported");
773 goto errout;
774 }
775
776 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
777 ops->policy, extack);
778 if (err < 0) {
779 NL_SET_ERR_MSG(extack, "Error parsing msg");
780 goto errout;
781 }
782
783 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
784 if (err)
785 goto errout;
786
787 if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
788 rule_exists(ops, frh, tb, rule)) {
789 err = -EEXIST;
790 goto errout_free;
791 }
792
793 err = ops->configure(rule, skb, frh, tb, extack);
794 if (err < 0)
795 goto errout_free;
796
797 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
798 extack);
799 if (err < 0)
800 goto errout_free;
801
802 list_for_each_entry(r, &ops->rules_list, list) {
803 if (r->pref == rule->target) {
804 RCU_INIT_POINTER(rule->ctarget, r);
805 break;
806 }
807 }
808
809 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
810 unresolved = 1;
811
812 list_for_each_entry(r, &ops->rules_list, list) {
813 if (r->pref > rule->pref)
814 break;
815 last = r;
816 }
817
818 if (last)
819 list_add_rcu(&rule->list, &last->list);
820 else
821 list_add_rcu(&rule->list, &ops->rules_list);
822
823 if (ops->unresolved_rules) {
824 /*
825 * There are unresolved goto rules in the list, check if
826 * any of them are pointing to this new rule.
827 */
828 list_for_each_entry(r, &ops->rules_list, list) {
829 if (r->action == FR_ACT_GOTO &&
830 r->target == rule->pref &&
831 rtnl_dereference(r->ctarget) == NULL) {
832 rcu_assign_pointer(r->ctarget, rule);
833 if (--ops->unresolved_rules == 0)
834 break;
835 }
836 }
837 }
838
839 if (rule->action == FR_ACT_GOTO)
840 ops->nr_goto_rules++;
841
842 if (unresolved)
843 ops->unresolved_rules++;
844
845 if (rule->tun_id)
846 ip_tunnel_need_metadata();
847
848 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
849 flush_route_cache(ops);
850 rules_ops_put(ops);
851 return 0;
852
853 errout_free:
854 kfree(rule);
855 errout:
856 rules_ops_put(ops);
857 return err;
858 }
859 EXPORT_SYMBOL_GPL(fib_nl_newrule);
860
861 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
862 struct netlink_ext_ack *extack)
863 {
864 struct net *net = sock_net(skb->sk);
865 struct fib_rule_hdr *frh = nlmsg_data(nlh);
866 struct fib_rules_ops *ops = NULL;
867 struct fib_rule *rule = NULL, *r, *nlrule = NULL;
868 struct nlattr *tb[FRA_MAX+1];
869 int err = -EINVAL;
870 bool user_priority = false;
871
872 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
873 NL_SET_ERR_MSG(extack, "Invalid msg length");
874 goto errout;
875 }
876
877 ops = lookup_rules_ops(net, frh->family);
878 if (ops == NULL) {
879 err = -EAFNOSUPPORT;
880 NL_SET_ERR_MSG(extack, "Rule family not supported");
881 goto errout;
882 }
883
884 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
885 ops->policy, extack);
886 if (err < 0) {
887 NL_SET_ERR_MSG(extack, "Error parsing msg");
888 goto errout;
889 }
890
891 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
892 if (err)
893 goto errout;
894
895 rule = rule_find(ops, frh, tb, nlrule, user_priority);
896 if (!rule) {
897 err = -ENOENT;
898 goto errout;
899 }
900
901 if (rule->flags & FIB_RULE_PERMANENT) {
902 err = -EPERM;
903 goto errout;
904 }
905
906 if (ops->delete) {
907 err = ops->delete(rule);
908 if (err)
909 goto errout;
910 }
911
912 if (rule->tun_id)
913 ip_tunnel_unneed_metadata();
914
915 list_del_rcu(&rule->list);
916
917 if (rule->action == FR_ACT_GOTO) {
918 ops->nr_goto_rules--;
919 if (rtnl_dereference(rule->ctarget) == NULL)
920 ops->unresolved_rules--;
921 }
922
923 /*
924 * Check if this rule is a target to any of them. If so,
925 * adjust to the next one with the same preference or
926 * disable them. As this operation is eventually very
927 * expensive, it is only performed if goto rules, except
928 * current if it is goto rule, have actually been added.
929 */
930 if (ops->nr_goto_rules > 0) {
931 struct fib_rule *n;
932
933 n = list_next_entry(rule, list);
934 if (&n->list == &ops->rules_list || n->pref != rule->pref)
935 n = NULL;
936 list_for_each_entry(r, &ops->rules_list, list) {
937 if (rtnl_dereference(r->ctarget) != rule)
938 continue;
939 rcu_assign_pointer(r->ctarget, n);
940 if (!n)
941 ops->unresolved_rules++;
942 }
943 }
944
945 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
946 NULL);
947 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
948 NETLINK_CB(skb).portid);
949 fib_rule_put(rule);
950 flush_route_cache(ops);
951 rules_ops_put(ops);
952 kfree(nlrule);
953 return 0;
954
955 errout:
956 kfree(nlrule);
957 rules_ops_put(ops);
958 return err;
959 }
960 EXPORT_SYMBOL_GPL(fib_nl_delrule);
961
962 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
963 struct fib_rule *rule)
964 {
965 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
966 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
967 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
968 + nla_total_size(4) /* FRA_PRIORITY */
969 + nla_total_size(4) /* FRA_TABLE */
970 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
971 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
972 + nla_total_size(4) /* FRA_FWMARK */
973 + nla_total_size(4) /* FRA_FWMASK */
974 + nla_total_size_64bit(8) /* FRA_TUN_ID */
975 + nla_total_size(sizeof(struct fib_kuid_range))
976 + nla_total_size(1) /* FRA_PROTOCOL */
977 + nla_total_size(1) /* FRA_IP_PROTO */
978 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
979 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
980
981 if (ops->nlmsg_payload)
982 payload += ops->nlmsg_payload(rule);
983
984 return payload;
985 }
986
987 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
988 u32 pid, u32 seq, int type, int flags,
989 struct fib_rules_ops *ops)
990 {
991 struct nlmsghdr *nlh;
992 struct fib_rule_hdr *frh;
993
994 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
995 if (nlh == NULL)
996 return -EMSGSIZE;
997
998 frh = nlmsg_data(nlh);
999 frh->family = ops->family;
1000 frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT;
1001 if (nla_put_u32(skb, FRA_TABLE, rule->table))
1002 goto nla_put_failure;
1003 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
1004 goto nla_put_failure;
1005 frh->res1 = 0;
1006 frh->res2 = 0;
1007 frh->action = rule->action;
1008 frh->flags = rule->flags;
1009
1010 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
1011 goto nla_put_failure;
1012
1013 if (rule->action == FR_ACT_GOTO &&
1014 rcu_access_pointer(rule->ctarget) == NULL)
1015 frh->flags |= FIB_RULE_UNRESOLVED;
1016
1017 if (rule->iifname[0]) {
1018 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
1019 goto nla_put_failure;
1020 if (rule->iifindex == -1)
1021 frh->flags |= FIB_RULE_IIF_DETACHED;
1022 }
1023
1024 if (rule->oifname[0]) {
1025 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
1026 goto nla_put_failure;
1027 if (rule->oifindex == -1)
1028 frh->flags |= FIB_RULE_OIF_DETACHED;
1029 }
1030
1031 if ((rule->pref &&
1032 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
1033 (rule->mark &&
1034 nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
1035 ((rule->mark_mask || rule->mark) &&
1036 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
1037 (rule->target &&
1038 nla_put_u32(skb, FRA_GOTO, rule->target)) ||
1039 (rule->tun_id &&
1040 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
1041 (rule->l3mdev &&
1042 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
1043 (uid_range_set(&rule->uid_range) &&
1044 nla_put_uid_range(skb, &rule->uid_range)) ||
1045 (fib_rule_port_range_set(&rule->sport_range) &&
1046 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
1047 (fib_rule_port_range_set(&rule->dport_range) &&
1048 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
1049 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
1050 goto nla_put_failure;
1051
1052 if (rule->suppress_ifgroup != -1) {
1053 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
1054 goto nla_put_failure;
1055 }
1056
1057 if (ops->fill(rule, skb, frh) < 0)
1058 goto nla_put_failure;
1059
1060 nlmsg_end(skb, nlh);
1061 return 0;
1062
1063 nla_put_failure:
1064 nlmsg_cancel(skb, nlh);
1065 return -EMSGSIZE;
1066 }
1067
1068 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
1069 struct fib_rules_ops *ops)
1070 {
1071 int idx = 0;
1072 struct fib_rule *rule;
1073 int err = 0;
1074
1075 rcu_read_lock();
1076 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
1077 if (idx < cb->args[1])
1078 goto skip;
1079
1080 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
1081 cb->nlh->nlmsg_seq, RTM_NEWRULE,
1082 NLM_F_MULTI, ops);
1083 if (err)
1084 break;
1085 skip:
1086 idx++;
1087 }
1088 rcu_read_unlock();
1089 cb->args[1] = idx;
1090 rules_ops_put(ops);
1091
1092 return err;
1093 }
1094
1095 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
1096 struct netlink_ext_ack *extack)
1097 {
1098 struct fib_rule_hdr *frh;
1099
1100 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1101 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
1102 return -EINVAL;
1103 }
1104
1105 frh = nlmsg_data(nlh);
1106 if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
1107 frh->res1 || frh->res2 || frh->action || frh->flags) {
1108 NL_SET_ERR_MSG(extack,
1109 "Invalid values in header for fib rule dump request");
1110 return -EINVAL;
1111 }
1112
1113 if (nlmsg_attrlen(nlh, sizeof(*frh))) {
1114 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
1115 return -EINVAL;
1116 }
1117
1118 return 0;
1119 }
1120
1121 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
1122 {
1123 const struct nlmsghdr *nlh = cb->nlh;
1124 struct net *net = sock_net(skb->sk);
1125 struct fib_rules_ops *ops;
1126 int idx = 0, family;
1127
1128 if (cb->strict_check) {
1129 int err = fib_valid_dumprule_req(nlh, cb->extack);
1130
1131 if (err < 0)
1132 return err;
1133 }
1134
1135 family = rtnl_msg_family(nlh);
1136 if (family != AF_UNSPEC) {
1137 /* Protocol specific dump request */
1138 ops = lookup_rules_ops(net, family);
1139 if (ops == NULL)
1140 return -EAFNOSUPPORT;
1141
1142 dump_rules(skb, cb, ops);
1143
1144 return skb->len;
1145 }
1146
1147 rcu_read_lock();
1148 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1149 if (idx < cb->args[0] || !try_module_get(ops->owner))
1150 goto skip;
1151
1152 if (dump_rules(skb, cb, ops) < 0)
1153 break;
1154
1155 cb->args[1] = 0;
1156 skip:
1157 idx++;
1158 }
1159 rcu_read_unlock();
1160 cb->args[0] = idx;
1161
1162 return skb->len;
1163 }
1164
1165 static void notify_rule_change(int event, struct fib_rule *rule,
1166 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1167 u32 pid)
1168 {
1169 struct net *net;
1170 struct sk_buff *skb;
1171 int err = -ENOMEM;
1172
1173 net = ops->fro_net;
1174 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1175 if (skb == NULL)
1176 goto errout;
1177
1178 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1179 if (err < 0) {
1180 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1181 WARN_ON(err == -EMSGSIZE);
1182 kfree_skb(skb);
1183 goto errout;
1184 }
1185
1186 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1187 return;
1188 errout:
1189 if (err < 0)
1190 rtnl_set_sk_err(net, ops->nlgroup, err);
1191 }
1192
1193 static void attach_rules(struct list_head *rules, struct net_device *dev)
1194 {
1195 struct fib_rule *rule;
1196
1197 list_for_each_entry(rule, rules, list) {
1198 if (rule->iifindex == -1 &&
1199 strcmp(dev->name, rule->iifname) == 0)
1200 rule->iifindex = dev->ifindex;
1201 if (rule->oifindex == -1 &&
1202 strcmp(dev->name, rule->oifname) == 0)
1203 rule->oifindex = dev->ifindex;
1204 }
1205 }
1206
1207 static void detach_rules(struct list_head *rules, struct net_device *dev)
1208 {
1209 struct fib_rule *rule;
1210
1211 list_for_each_entry(rule, rules, list) {
1212 if (rule->iifindex == dev->ifindex)
1213 rule->iifindex = -1;
1214 if (rule->oifindex == dev->ifindex)
1215 rule->oifindex = -1;
1216 }
1217 }
1218
1219
1220 static int fib_rules_event(struct notifier_block *this, unsigned long event,
1221 void *ptr)
1222 {
1223 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1224 struct net *net = dev_net(dev);
1225 struct fib_rules_ops *ops;
1226
1227 ASSERT_RTNL();
1228
1229 switch (event) {
1230 case NETDEV_REGISTER:
1231 list_for_each_entry(ops, &net->rules_ops, list)
1232 attach_rules(&ops->rules_list, dev);
1233 break;
1234
1235 case NETDEV_CHANGENAME:
1236 list_for_each_entry(ops, &net->rules_ops, list) {
1237 detach_rules(&ops->rules_list, dev);
1238 attach_rules(&ops->rules_list, dev);
1239 }
1240 break;
1241
1242 case NETDEV_UNREGISTER:
1243 list_for_each_entry(ops, &net->rules_ops, list)
1244 detach_rules(&ops->rules_list, dev);
1245 break;
1246 }
1247
1248 return NOTIFY_DONE;
1249 }
1250
1251 static struct notifier_block fib_rules_notifier = {
1252 .notifier_call = fib_rules_event,
1253 };
1254
1255 static int __net_init fib_rules_net_init(struct net *net)
1256 {
1257 INIT_LIST_HEAD(&net->rules_ops);
1258 spin_lock_init(&net->rules_mod_lock);
1259 return 0;
1260 }
1261
1262 static void __net_exit fib_rules_net_exit(struct net *net)
1263 {
1264 WARN_ON_ONCE(!list_empty(&net->rules_ops));
1265 }
1266
1267 static struct pernet_operations fib_rules_net_ops = {
1268 .init = fib_rules_net_init,
1269 .exit = fib_rules_net_exit,
1270 };
1271
1272 static int __init fib_rules_init(void)
1273 {
1274 int err;
1275 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1276 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1277 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1278
1279 err = register_pernet_subsys(&fib_rules_net_ops);
1280 if (err < 0)
1281 goto fail;
1282
1283 err = register_netdevice_notifier(&fib_rules_notifier);
1284 if (err < 0)
1285 goto fail_unregister;
1286
1287 return 0;
1288
1289 fail_unregister:
1290 unregister_pernet_subsys(&fib_rules_net_ops);
1291 fail:
1292 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1293 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1294 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1295 return err;
1296 }
1297
1298 subsys_initcall(fib_rules_init);
1299
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