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