Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 struct fib_rule *rule_find(struct fib_rules_ops *ops,
391 struct fib_rule_hdr *frh,
392 struct nlattr **tb,
393 struct fib_rule *rule,
394 bool user_priority)
395{
396 struct fib_rule *r;
397
398 list_for_each_entry(r, &ops->rules_list, list) {
399 if (rule->action && r->action != rule->action)
400 continue;
401
402 if (rule->table && r->table != rule->table)
403 continue;
404
405 if (user_priority && r->pref != rule->pref)
406 continue;
407
408 if (rule->iifname[0] &&
409 memcmp(r->iifname, rule->iifname, IFNAMSIZ))
410 continue;
411
412 if (rule->oifname[0] &&
413 memcmp(r->oifname, rule->oifname, IFNAMSIZ))
414 continue;
415
416 if (rule->mark && r->mark != rule->mark)
417 continue;
418
419 if (rule->mark_mask && r->mark_mask != rule->mark_mask)
420 continue;
421
422 if (rule->tun_id && r->tun_id != rule->tun_id)
423 continue;
424
425 if (r->fr_net != rule->fr_net)
426 continue;
427
428 if (rule->l3mdev && r->l3mdev != rule->l3mdev)
429 continue;
430
431 if (uid_range_set(&rule->uid_range) &&
432 (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
433 !uid_eq(r->uid_range.end, rule->uid_range.end)))
434 continue;
435
436 if (rule->ip_proto && r->ip_proto != rule->ip_proto)
437 continue;
438
439 if (fib_rule_port_range_set(&rule->sport_range) &&
440 !fib_rule_port_range_compare(&r->sport_range,
441 &rule->sport_range))
442 continue;
443
444 if (fib_rule_port_range_set(&rule->dport_range) &&
445 !fib_rule_port_range_compare(&r->dport_range,
446 &rule->dport_range))
447 continue;
448
449 if (!ops->compare(r, frh, tb))
450 continue;
451 return r;
452 }
453
454 return NULL;
455}
456
457#ifdef CONFIG_NET_L3_MASTER_DEV
458static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
459 struct netlink_ext_ack *extack)
460{
461 nlrule->l3mdev = nla_get_u8(nla);
462 if (nlrule->l3mdev != 1) {
463 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
464 return -1;
465 }
466
467 return 0;
468}
469#else
470static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
471 struct netlink_ext_ack *extack)
472{
473 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
474 return -1;
475}
476#endif
477
478static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
479 struct netlink_ext_ack *extack,
480 struct fib_rules_ops *ops,
481 struct nlattr *tb[],
482 struct fib_rule **rule,
483 bool *user_priority)
484{
485 struct net *net = sock_net(skb->sk);
486 struct fib_rule_hdr *frh = nlmsg_data(nlh);
487 struct fib_rule *nlrule = NULL;
488 int err = -EINVAL;
489
490 if (frh->src_len)
491 if (!tb[FRA_SRC] ||
492 frh->src_len > (ops->addr_size * 8) ||
493 nla_len(tb[FRA_SRC]) != ops->addr_size) {
494 NL_SET_ERR_MSG(extack, "Invalid source address");
495 goto errout;
496 }
497
498 if (frh->dst_len)
499 if (!tb[FRA_DST] ||
500 frh->dst_len > (ops->addr_size * 8) ||
501 nla_len(tb[FRA_DST]) != ops->addr_size) {
502 NL_SET_ERR_MSG(extack, "Invalid dst address");
503 goto errout;
504 }
505
506 nlrule = kzalloc(ops->rule_size, GFP_KERNEL);
507 if (!nlrule) {
508 err = -ENOMEM;
509 goto errout;
510 }
511 refcount_set(&nlrule->refcnt, 1);
512 nlrule->fr_net = net;
513
514 if (tb[FRA_PRIORITY]) {
515 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
516 *user_priority = true;
517 } else {
518 nlrule->pref = fib_default_rule_pref(ops);
519 }
520
521 nlrule->proto = tb[FRA_PROTOCOL] ?
522 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
523
524 if (tb[FRA_IIFNAME]) {
525 struct net_device *dev;
526
527 nlrule->iifindex = -1;
528 nla_strlcpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
529 dev = __dev_get_by_name(net, nlrule->iifname);
530 if (dev)
531 nlrule->iifindex = dev->ifindex;
532 }
533
534 if (tb[FRA_OIFNAME]) {
535 struct net_device *dev;
536
537 nlrule->oifindex = -1;
538 nla_strlcpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
539 dev = __dev_get_by_name(net, nlrule->oifname);
540 if (dev)
541 nlrule->oifindex = dev->ifindex;
542 }
543
544 if (tb[FRA_FWMARK]) {
545 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
546 if (nlrule->mark)
547 /* compatibility: if the mark value is non-zero all bits
548 * are compared unless a mask is explicitly specified.
549 */
550 nlrule->mark_mask = 0xFFFFFFFF;
551 }
552
553 if (tb[FRA_FWMASK])
554 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
555
556 if (tb[FRA_TUN_ID])
557 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
558
559 err = -EINVAL;
560 if (tb[FRA_L3MDEV] &&
561 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
562 goto errout_free;
563
564 nlrule->action = frh->action;
565 nlrule->flags = frh->flags;
566 nlrule->table = frh_get_table(frh, tb);
567 if (tb[FRA_SUPPRESS_PREFIXLEN])
568 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
569 else
570 nlrule->suppress_prefixlen = -1;
571
572 if (tb[FRA_SUPPRESS_IFGROUP])
573 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
574 else
575 nlrule->suppress_ifgroup = -1;
576
577 if (tb[FRA_GOTO]) {
578 if (nlrule->action != FR_ACT_GOTO) {
579 NL_SET_ERR_MSG(extack, "Unexpected goto");
580 goto errout_free;
581 }
582
583 nlrule->target = nla_get_u32(tb[FRA_GOTO]);
584 /* Backward jumps are prohibited to avoid endless loops */
585 if (nlrule->target <= nlrule->pref) {
586 NL_SET_ERR_MSG(extack, "Backward goto not supported");
587 goto errout_free;
588 }
589 } else if (nlrule->action == FR_ACT_GOTO) {
590 NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
591 goto errout_free;
592 }
593
594 if (nlrule->l3mdev && nlrule->table) {
595 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
596 goto errout_free;
597 }
598
599 if (tb[FRA_UID_RANGE]) {
600 if (current_user_ns() != net->user_ns) {
601 err = -EPERM;
602 NL_SET_ERR_MSG(extack, "No permission to set uid");
603 goto errout_free;
604 }
605
606 nlrule->uid_range = nla_get_kuid_range(tb);
607
608 if (!uid_range_set(&nlrule->uid_range) ||
609 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
610 NL_SET_ERR_MSG(extack, "Invalid uid range");
611 goto errout_free;
612 }
613 } else {
614 nlrule->uid_range = fib_kuid_range_unset;
615 }
616
617 if (tb[FRA_IP_PROTO])
618 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
619
620 if (tb[FRA_SPORT_RANGE]) {
621 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
622 &nlrule->sport_range);
623 if (err) {
624 NL_SET_ERR_MSG(extack, "Invalid sport range");
625 goto errout_free;
626 }
627 }
628
629 if (tb[FRA_DPORT_RANGE]) {
630 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
631 &nlrule->dport_range);
632 if (err) {
633 NL_SET_ERR_MSG(extack, "Invalid dport range");
634 goto errout_free;
635 }
636 }
637
638 *rule = nlrule;
639
640 return 0;
641
642errout_free:
643 kfree(nlrule);
644errout:
645 return err;
646}
647
648int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
649 struct netlink_ext_ack *extack)
650{
651 struct net *net = sock_net(skb->sk);
652 struct fib_rule_hdr *frh = nlmsg_data(nlh);
653 struct fib_rules_ops *ops = NULL;
654 struct fib_rule *rule = NULL, *r, *last = NULL;
655 struct nlattr *tb[FRA_MAX + 1];
656 int err = -EINVAL, unresolved = 0;
657 bool user_priority = false;
658
659 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
660 NL_SET_ERR_MSG(extack, "Invalid msg length");
661 goto errout;
662 }
663
664 ops = lookup_rules_ops(net, frh->family);
665 if (!ops) {
666 err = -EAFNOSUPPORT;
667 NL_SET_ERR_MSG(extack, "Rule family not supported");
668 goto errout;
669 }
670
671 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
672 if (err < 0) {
673 NL_SET_ERR_MSG(extack, "Error parsing msg");
674 goto errout;
675 }
676
677 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
678 if (err)
679 goto errout;
680
681 if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
682 rule_find(ops, frh, tb, rule, user_priority)) {
683 err = -EEXIST;
684 goto errout_free;
685 }
686
687 err = ops->configure(rule, skb, frh, tb, extack);
688 if (err < 0)
689 goto errout_free;
690
691 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
692 extack);
693 if (err < 0)
694 goto errout_free;
695
696 list_for_each_entry(r, &ops->rules_list, list) {
697 if (r->pref == rule->target) {
698 RCU_INIT_POINTER(rule->ctarget, r);
699 break;
700 }
701 }
702
703 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
704 unresolved = 1;
705
706 list_for_each_entry(r, &ops->rules_list, list) {
707 if (r->pref > rule->pref)
708 break;
709 last = r;
710 }
711
712 if (last)
713 list_add_rcu(&rule->list, &last->list);
714 else
715 list_add_rcu(&rule->list, &ops->rules_list);
716
717 if (ops->unresolved_rules) {
718 /*
719 * There are unresolved goto rules in the list, check if
720 * any of them are pointing to this new rule.
721 */
722 list_for_each_entry(r, &ops->rules_list, list) {
723 if (r->action == FR_ACT_GOTO &&
724 r->target == rule->pref &&
725 rtnl_dereference(r->ctarget) == NULL) {
726 rcu_assign_pointer(r->ctarget, rule);
727 if (--ops->unresolved_rules == 0)
728 break;
729 }
730 }
731 }
732
733 if (rule->action == FR_ACT_GOTO)
734 ops->nr_goto_rules++;
735
736 if (unresolved)
737 ops->unresolved_rules++;
738
739 if (rule->tun_id)
740 ip_tunnel_need_metadata();
741
742 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
743 flush_route_cache(ops);
744 rules_ops_put(ops);
745 return 0;
746
747errout_free:
748 kfree(rule);
749errout:
750 rules_ops_put(ops);
751 return err;
752}
753EXPORT_SYMBOL_GPL(fib_nl_newrule);
754
755int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
756 struct netlink_ext_ack *extack)
757{
758 struct net *net = sock_net(skb->sk);
759 struct fib_rule_hdr *frh = nlmsg_data(nlh);
760 struct fib_rules_ops *ops = NULL;
761 struct fib_rule *rule = NULL, *r, *nlrule = NULL;
762 struct nlattr *tb[FRA_MAX+1];
763 int err = -EINVAL;
764 bool user_priority = false;
765
766 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
767 NL_SET_ERR_MSG(extack, "Invalid msg length");
768 goto errout;
769 }
770
771 ops = lookup_rules_ops(net, frh->family);
772 if (ops == NULL) {
773 err = -EAFNOSUPPORT;
774 NL_SET_ERR_MSG(extack, "Rule family not supported");
775 goto errout;
776 }
777
778 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
779 if (err < 0) {
780 NL_SET_ERR_MSG(extack, "Error parsing msg");
781 goto errout;
782 }
783
784 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
785 if (err)
786 goto errout;
787
788 rule = rule_find(ops, frh, tb, nlrule, user_priority);
789 if (!rule) {
790 err = -ENOENT;
791 goto errout;
792 }
793
794 if (rule->flags & FIB_RULE_PERMANENT) {
795 err = -EPERM;
796 goto errout;
797 }
798
799 if (ops->delete) {
800 err = ops->delete(rule);
801 if (err)
802 goto errout;
803 }
804
805 if (rule->tun_id)
806 ip_tunnel_unneed_metadata();
807
808 list_del_rcu(&rule->list);
809
810 if (rule->action == FR_ACT_GOTO) {
811 ops->nr_goto_rules--;
812 if (rtnl_dereference(rule->ctarget) == NULL)
813 ops->unresolved_rules--;
814 }
815
816 /*
817 * Check if this rule is a target to any of them. If so,
818 * adjust to the next one with the same preference or
819 * disable them. As this operation is eventually very
820 * expensive, it is only performed if goto rules, except
821 * current if it is goto rule, have actually been added.
822 */
823 if (ops->nr_goto_rules > 0) {
824 struct fib_rule *n;
825
826 n = list_next_entry(rule, list);
827 if (&n->list == &ops->rules_list || n->pref != rule->pref)
828 n = NULL;
829 list_for_each_entry(r, &ops->rules_list, list) {
830 if (rtnl_dereference(r->ctarget) != rule)
831 continue;
832 rcu_assign_pointer(r->ctarget, n);
833 if (!n)
834 ops->unresolved_rules++;
835 }
836 }
837
838 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
839 NULL);
840 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
841 NETLINK_CB(skb).portid);
842 fib_rule_put(rule);
843 flush_route_cache(ops);
844 rules_ops_put(ops);
845 kfree(nlrule);
846 return 0;
847
848errout:
849 if (nlrule)
850 kfree(nlrule);
851 rules_ops_put(ops);
852 return err;
853}
854EXPORT_SYMBOL_GPL(fib_nl_delrule);
855
856static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
857 struct fib_rule *rule)
858{
859 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
860 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
861 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
862 + nla_total_size(4) /* FRA_PRIORITY */
863 + nla_total_size(4) /* FRA_TABLE */
864 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
865 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
866 + nla_total_size(4) /* FRA_FWMARK */
867 + nla_total_size(4) /* FRA_FWMASK */
868 + nla_total_size_64bit(8) /* FRA_TUN_ID */
869 + nla_total_size(sizeof(struct fib_kuid_range))
870 + nla_total_size(1) /* FRA_PROTOCOL */
871 + nla_total_size(1) /* FRA_IP_PROTO */
872 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
873 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
874
875 if (ops->nlmsg_payload)
876 payload += ops->nlmsg_payload(rule);
877
878 return payload;
879}
880
881static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
882 u32 pid, u32 seq, int type, int flags,
883 struct fib_rules_ops *ops)
884{
885 struct nlmsghdr *nlh;
886 struct fib_rule_hdr *frh;
887
888 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
889 if (nlh == NULL)
890 return -EMSGSIZE;
891
892 frh = nlmsg_data(nlh);
893 frh->family = ops->family;
894 frh->table = rule->table;
895 if (nla_put_u32(skb, FRA_TABLE, rule->table))
896 goto nla_put_failure;
897 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
898 goto nla_put_failure;
899 frh->res1 = 0;
900 frh->res2 = 0;
901 frh->action = rule->action;
902 frh->flags = rule->flags;
903
904 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
905 goto nla_put_failure;
906
907 if (rule->action == FR_ACT_GOTO &&
908 rcu_access_pointer(rule->ctarget) == NULL)
909 frh->flags |= FIB_RULE_UNRESOLVED;
910
911 if (rule->iifname[0]) {
912 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
913 goto nla_put_failure;
914 if (rule->iifindex == -1)
915 frh->flags |= FIB_RULE_IIF_DETACHED;
916 }
917
918 if (rule->oifname[0]) {
919 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
920 goto nla_put_failure;
921 if (rule->oifindex == -1)
922 frh->flags |= FIB_RULE_OIF_DETACHED;
923 }
924
925 if ((rule->pref &&
926 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
927 (rule->mark &&
928 nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
929 ((rule->mark_mask || rule->mark) &&
930 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
931 (rule->target &&
932 nla_put_u32(skb, FRA_GOTO, rule->target)) ||
933 (rule->tun_id &&
934 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
935 (rule->l3mdev &&
936 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
937 (uid_range_set(&rule->uid_range) &&
938 nla_put_uid_range(skb, &rule->uid_range)) ||
939 (fib_rule_port_range_set(&rule->sport_range) &&
940 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
941 (fib_rule_port_range_set(&rule->dport_range) &&
942 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
943 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
944 goto nla_put_failure;
945
946 if (rule->suppress_ifgroup != -1) {
947 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
948 goto nla_put_failure;
949 }
950
951 if (ops->fill(rule, skb, frh) < 0)
952 goto nla_put_failure;
953
954 nlmsg_end(skb, nlh);
955 return 0;
956
957nla_put_failure:
958 nlmsg_cancel(skb, nlh);
959 return -EMSGSIZE;
960}
961
962static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
963 struct fib_rules_ops *ops)
964{
965 int idx = 0;
966 struct fib_rule *rule;
967 int err = 0;
968
969 rcu_read_lock();
970 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
971 if (idx < cb->args[1])
972 goto skip;
973
974 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
975 cb->nlh->nlmsg_seq, RTM_NEWRULE,
976 NLM_F_MULTI, ops);
977 if (err)
978 break;
979skip:
980 idx++;
981 }
982 rcu_read_unlock();
983 cb->args[1] = idx;
984 rules_ops_put(ops);
985
986 return err;
987}
988
989static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
990{
991 struct net *net = sock_net(skb->sk);
992 struct fib_rules_ops *ops;
993 int idx = 0, family;
994
995 family = rtnl_msg_family(cb->nlh);
996 if (family != AF_UNSPEC) {
997 /* Protocol specific dump request */
998 ops = lookup_rules_ops(net, family);
999 if (ops == NULL)
1000 return -EAFNOSUPPORT;
1001
1002 dump_rules(skb, cb, ops);
1003
1004 return skb->len;
1005 }
1006
1007 rcu_read_lock();
1008 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1009 if (idx < cb->args[0] || !try_module_get(ops->owner))
1010 goto skip;
1011
1012 if (dump_rules(skb, cb, ops) < 0)
1013 break;
1014
1015 cb->args[1] = 0;
1016skip:
1017 idx++;
1018 }
1019 rcu_read_unlock();
1020 cb->args[0] = idx;
1021
1022 return skb->len;
1023}
1024
1025static void notify_rule_change(int event, struct fib_rule *rule,
1026 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1027 u32 pid)
1028{
1029 struct net *net;
1030 struct sk_buff *skb;
1031 int err = -ENOBUFS;
1032
1033 net = ops->fro_net;
1034 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1035 if (skb == NULL)
1036 goto errout;
1037
1038 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1039 if (err < 0) {
1040 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1041 WARN_ON(err == -EMSGSIZE);
1042 kfree_skb(skb);
1043 goto errout;
1044 }
1045
1046 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1047 return;
1048errout:
1049 if (err < 0)
1050 rtnl_set_sk_err(net, ops->nlgroup, err);
1051}
1052
1053static void attach_rules(struct list_head *rules, struct net_device *dev)
1054{
1055 struct fib_rule *rule;
1056
1057 list_for_each_entry(rule, rules, list) {
1058 if (rule->iifindex == -1 &&
1059 strcmp(dev->name, rule->iifname) == 0)
1060 rule->iifindex = dev->ifindex;
1061 if (rule->oifindex == -1 &&
1062 strcmp(dev->name, rule->oifname) == 0)
1063 rule->oifindex = dev->ifindex;
1064 }
1065}
1066
1067static void detach_rules(struct list_head *rules, struct net_device *dev)
1068{
1069 struct fib_rule *rule;
1070
1071 list_for_each_entry(rule, rules, list) {
1072 if (rule->iifindex == dev->ifindex)
1073 rule->iifindex = -1;
1074 if (rule->oifindex == dev->ifindex)
1075 rule->oifindex = -1;
1076 }
1077}
1078
1079
1080static int fib_rules_event(struct notifier_block *this, unsigned long event,
1081 void *ptr)
1082{
1083 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1084 struct net *net = dev_net(dev);
1085 struct fib_rules_ops *ops;
1086
1087 ASSERT_RTNL();
1088
1089 switch (event) {
1090 case NETDEV_REGISTER:
1091 list_for_each_entry(ops, &net->rules_ops, list)
1092 attach_rules(&ops->rules_list, dev);
1093 break;
1094
1095 case NETDEV_CHANGENAME:
1096 list_for_each_entry(ops, &net->rules_ops, list) {
1097 detach_rules(&ops->rules_list, dev);
1098 attach_rules(&ops->rules_list, dev);
1099 }
1100 break;
1101
1102 case NETDEV_UNREGISTER:
1103 list_for_each_entry(ops, &net->rules_ops, list)
1104 detach_rules(&ops->rules_list, dev);
1105 break;
1106 }
1107
1108 return NOTIFY_DONE;
1109}
1110
1111static struct notifier_block fib_rules_notifier = {
1112 .notifier_call = fib_rules_event,
1113};
1114
1115static int __net_init fib_rules_net_init(struct net *net)
1116{
1117 INIT_LIST_HEAD(&net->rules_ops);
1118 spin_lock_init(&net->rules_mod_lock);
1119 return 0;
1120}
1121
1122static void __net_exit fib_rules_net_exit(struct net *net)
1123{
1124 WARN_ON_ONCE(!list_empty(&net->rules_ops));
1125}
1126
1127static struct pernet_operations fib_rules_net_ops = {
1128 .init = fib_rules_net_init,
1129 .exit = fib_rules_net_exit,
1130};
1131
1132static int __init fib_rules_init(void)
1133{
1134 int err;
1135 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1136 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1137 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1138
1139 err = register_pernet_subsys(&fib_rules_net_ops);
1140 if (err < 0)
1141 goto fail;
1142
1143 err = register_netdevice_notifier(&fib_rules_notifier);
1144 if (err < 0)
1145 goto fail_unregister;
1146
1147 return 0;
1148
1149fail_unregister:
1150 unregister_pernet_subsys(&fib_rules_net_ops);
1151fail:
1152 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1153 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1154 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1155 return err;
1156}
1157
1158subsys_initcall(fib_rules_init);