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