Loading...
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/*
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 <net/net_namespace.h>
16#include <net/sock.h>
17#include <net/fib_rules.h>
18
19int fib_default_rule_add(struct fib_rules_ops *ops,
20 u32 pref, u32 table, u32 flags)
21{
22 struct fib_rule *r;
23
24 r = kzalloc(ops->rule_size, GFP_KERNEL);
25 if (r == NULL)
26 return -ENOMEM;
27
28 atomic_set(&r->refcnt, 1);
29 r->action = FR_ACT_TO_TBL;
30 r->pref = pref;
31 r->table = table;
32 r->flags = flags;
33 r->fr_net = hold_net(ops->fro_net);
34
35 /* The lock is not required here, the list in unreacheable
36 * at the moment this function is called */
37 list_add_tail(&r->list, &ops->rules_list);
38 return 0;
39}
40EXPORT_SYMBOL(fib_default_rule_add);
41
42u32 fib_default_rule_pref(struct fib_rules_ops *ops)
43{
44 struct list_head *pos;
45 struct fib_rule *rule;
46
47 if (!list_empty(&ops->rules_list)) {
48 pos = ops->rules_list.next;
49 if (pos->next != &ops->rules_list) {
50 rule = list_entry(pos->next, struct fib_rule, list);
51 if (rule->pref)
52 return rule->pref - 1;
53 }
54 }
55
56 return 0;
57}
58EXPORT_SYMBOL(fib_default_rule_pref);
59
60static void notify_rule_change(int event, struct fib_rule *rule,
61 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
62 u32 pid);
63
64static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
65{
66 struct fib_rules_ops *ops;
67
68 rcu_read_lock();
69 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
70 if (ops->family == family) {
71 if (!try_module_get(ops->owner))
72 ops = NULL;
73 rcu_read_unlock();
74 return ops;
75 }
76 }
77 rcu_read_unlock();
78
79 return NULL;
80}
81
82static void rules_ops_put(struct fib_rules_ops *ops)
83{
84 if (ops)
85 module_put(ops->owner);
86}
87
88static void flush_route_cache(struct fib_rules_ops *ops)
89{
90 if (ops->flush_cache)
91 ops->flush_cache(ops);
92}
93
94static int __fib_rules_register(struct fib_rules_ops *ops)
95{
96 int err = -EEXIST;
97 struct fib_rules_ops *o;
98 struct net *net;
99
100 net = ops->fro_net;
101
102 if (ops->rule_size < sizeof(struct fib_rule))
103 return -EINVAL;
104
105 if (ops->match == NULL || ops->configure == NULL ||
106 ops->compare == NULL || ops->fill == NULL ||
107 ops->action == NULL)
108 return -EINVAL;
109
110 spin_lock(&net->rules_mod_lock);
111 list_for_each_entry(o, &net->rules_ops, list)
112 if (ops->family == o->family)
113 goto errout;
114
115 hold_net(net);
116 list_add_tail_rcu(&ops->list, &net->rules_ops);
117 err = 0;
118errout:
119 spin_unlock(&net->rules_mod_lock);
120
121 return err;
122}
123
124struct fib_rules_ops *
125fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
126{
127 struct fib_rules_ops *ops;
128 int err;
129
130 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
131 if (ops == NULL)
132 return ERR_PTR(-ENOMEM);
133
134 INIT_LIST_HEAD(&ops->rules_list);
135 ops->fro_net = net;
136
137 err = __fib_rules_register(ops);
138 if (err) {
139 kfree(ops);
140 ops = ERR_PTR(err);
141 }
142
143 return ops;
144}
145EXPORT_SYMBOL_GPL(fib_rules_register);
146
147static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
148{
149 struct fib_rule *rule, *tmp;
150
151 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
152 list_del_rcu(&rule->list);
153 fib_rule_put(rule);
154 }
155}
156
157static void fib_rules_put_rcu(struct rcu_head *head)
158{
159 struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu);
160 struct net *net = ops->fro_net;
161
162 release_net(net);
163 kfree(ops);
164}
165
166void fib_rules_unregister(struct fib_rules_ops *ops)
167{
168 struct net *net = ops->fro_net;
169
170 spin_lock(&net->rules_mod_lock);
171 list_del_rcu(&ops->list);
172 fib_rules_cleanup_ops(ops);
173 spin_unlock(&net->rules_mod_lock);
174
175 call_rcu(&ops->rcu, fib_rules_put_rcu);
176}
177EXPORT_SYMBOL_GPL(fib_rules_unregister);
178
179static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
180 struct flowi *fl, int flags)
181{
182 int ret = 0;
183
184 if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
185 goto out;
186
187 if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
188 goto out;
189
190 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
191 goto out;
192
193 ret = ops->match(rule, fl, flags);
194out:
195 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
196}
197
198int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
199 int flags, struct fib_lookup_arg *arg)
200{
201 struct fib_rule *rule;
202 int err;
203
204 rcu_read_lock();
205
206 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
207jumped:
208 if (!fib_rule_match(rule, ops, fl, flags))
209 continue;
210
211 if (rule->action == FR_ACT_GOTO) {
212 struct fib_rule *target;
213
214 target = rcu_dereference(rule->ctarget);
215 if (target == NULL) {
216 continue;
217 } else {
218 rule = target;
219 goto jumped;
220 }
221 } else if (rule->action == FR_ACT_NOP)
222 continue;
223 else
224 err = ops->action(rule, fl, flags, arg);
225
226 if (err != -EAGAIN) {
227 if ((arg->flags & FIB_LOOKUP_NOREF) ||
228 likely(atomic_inc_not_zero(&rule->refcnt))) {
229 arg->rule = rule;
230 goto out;
231 }
232 break;
233 }
234 }
235
236 err = -ESRCH;
237out:
238 rcu_read_unlock();
239
240 return err;
241}
242EXPORT_SYMBOL_GPL(fib_rules_lookup);
243
244static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
245 struct fib_rules_ops *ops)
246{
247 int err = -EINVAL;
248
249 if (frh->src_len)
250 if (tb[FRA_SRC] == NULL ||
251 frh->src_len > (ops->addr_size * 8) ||
252 nla_len(tb[FRA_SRC]) != ops->addr_size)
253 goto errout;
254
255 if (frh->dst_len)
256 if (tb[FRA_DST] == NULL ||
257 frh->dst_len > (ops->addr_size * 8) ||
258 nla_len(tb[FRA_DST]) != ops->addr_size)
259 goto errout;
260
261 err = 0;
262errout:
263 return err;
264}
265
266static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
267{
268 struct net *net = sock_net(skb->sk);
269 struct fib_rule_hdr *frh = nlmsg_data(nlh);
270 struct fib_rules_ops *ops = NULL;
271 struct fib_rule *rule, *r, *last = NULL;
272 struct nlattr *tb[FRA_MAX+1];
273 int err = -EINVAL, unresolved = 0;
274
275 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
276 goto errout;
277
278 ops = lookup_rules_ops(net, frh->family);
279 if (ops == NULL) {
280 err = -EAFNOSUPPORT;
281 goto errout;
282 }
283
284 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
285 if (err < 0)
286 goto errout;
287
288 err = validate_rulemsg(frh, tb, ops);
289 if (err < 0)
290 goto errout;
291
292 rule = kzalloc(ops->rule_size, GFP_KERNEL);
293 if (rule == NULL) {
294 err = -ENOMEM;
295 goto errout;
296 }
297 rule->fr_net = hold_net(net);
298
299 if (tb[FRA_PRIORITY])
300 rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
301
302 if (tb[FRA_IIFNAME]) {
303 struct net_device *dev;
304
305 rule->iifindex = -1;
306 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
307 dev = __dev_get_by_name(net, rule->iifname);
308 if (dev)
309 rule->iifindex = dev->ifindex;
310 }
311
312 if (tb[FRA_OIFNAME]) {
313 struct net_device *dev;
314
315 rule->oifindex = -1;
316 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
317 dev = __dev_get_by_name(net, rule->oifname);
318 if (dev)
319 rule->oifindex = dev->ifindex;
320 }
321
322 if (tb[FRA_FWMARK]) {
323 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
324 if (rule->mark)
325 /* compatibility: if the mark value is non-zero all bits
326 * are compared unless a mask is explicitly specified.
327 */
328 rule->mark_mask = 0xFFFFFFFF;
329 }
330
331 if (tb[FRA_FWMASK])
332 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
333
334 rule->action = frh->action;
335 rule->flags = frh->flags;
336 rule->table = frh_get_table(frh, tb);
337
338 if (!tb[FRA_PRIORITY] && ops->default_pref)
339 rule->pref = ops->default_pref(ops);
340
341 err = -EINVAL;
342 if (tb[FRA_GOTO]) {
343 if (rule->action != FR_ACT_GOTO)
344 goto errout_free;
345
346 rule->target = nla_get_u32(tb[FRA_GOTO]);
347 /* Backward jumps are prohibited to avoid endless loops */
348 if (rule->target <= rule->pref)
349 goto errout_free;
350
351 list_for_each_entry(r, &ops->rules_list, list) {
352 if (r->pref == rule->target) {
353 RCU_INIT_POINTER(rule->ctarget, r);
354 break;
355 }
356 }
357
358 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
359 unresolved = 1;
360 } else if (rule->action == FR_ACT_GOTO)
361 goto errout_free;
362
363 err = ops->configure(rule, skb, frh, tb);
364 if (err < 0)
365 goto errout_free;
366
367 list_for_each_entry(r, &ops->rules_list, list) {
368 if (r->pref > rule->pref)
369 break;
370 last = r;
371 }
372
373 fib_rule_get(rule);
374
375 if (last)
376 list_add_rcu(&rule->list, &last->list);
377 else
378 list_add_rcu(&rule->list, &ops->rules_list);
379
380 if (ops->unresolved_rules) {
381 /*
382 * There are unresolved goto rules in the list, check if
383 * any of them are pointing to this new rule.
384 */
385 list_for_each_entry(r, &ops->rules_list, list) {
386 if (r->action == FR_ACT_GOTO &&
387 r->target == rule->pref &&
388 rtnl_dereference(r->ctarget) == NULL) {
389 rcu_assign_pointer(r->ctarget, rule);
390 if (--ops->unresolved_rules == 0)
391 break;
392 }
393 }
394 }
395
396 if (rule->action == FR_ACT_GOTO)
397 ops->nr_goto_rules++;
398
399 if (unresolved)
400 ops->unresolved_rules++;
401
402 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
403 flush_route_cache(ops);
404 rules_ops_put(ops);
405 return 0;
406
407errout_free:
408 release_net(rule->fr_net);
409 kfree(rule);
410errout:
411 rules_ops_put(ops);
412 return err;
413}
414
415static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
416{
417 struct net *net = sock_net(skb->sk);
418 struct fib_rule_hdr *frh = nlmsg_data(nlh);
419 struct fib_rules_ops *ops = NULL;
420 struct fib_rule *rule, *tmp;
421 struct nlattr *tb[FRA_MAX+1];
422 int err = -EINVAL;
423
424 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
425 goto errout;
426
427 ops = lookup_rules_ops(net, frh->family);
428 if (ops == NULL) {
429 err = -EAFNOSUPPORT;
430 goto errout;
431 }
432
433 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
434 if (err < 0)
435 goto errout;
436
437 err = validate_rulemsg(frh, tb, ops);
438 if (err < 0)
439 goto errout;
440
441 list_for_each_entry(rule, &ops->rules_list, list) {
442 if (frh->action && (frh->action != rule->action))
443 continue;
444
445 if (frh->table && (frh_get_table(frh, tb) != rule->table))
446 continue;
447
448 if (tb[FRA_PRIORITY] &&
449 (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
450 continue;
451
452 if (tb[FRA_IIFNAME] &&
453 nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
454 continue;
455
456 if (tb[FRA_OIFNAME] &&
457 nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
458 continue;
459
460 if (tb[FRA_FWMARK] &&
461 (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
462 continue;
463
464 if (tb[FRA_FWMASK] &&
465 (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
466 continue;
467
468 if (!ops->compare(rule, frh, tb))
469 continue;
470
471 if (rule->flags & FIB_RULE_PERMANENT) {
472 err = -EPERM;
473 goto errout;
474 }
475
476 list_del_rcu(&rule->list);
477
478 if (rule->action == FR_ACT_GOTO) {
479 ops->nr_goto_rules--;
480 if (rtnl_dereference(rule->ctarget) == NULL)
481 ops->unresolved_rules--;
482 }
483
484 /*
485 * Check if this rule is a target to any of them. If so,
486 * disable them. As this operation is eventually very
487 * expensive, it is only performed if goto rules have
488 * actually been added.
489 */
490 if (ops->nr_goto_rules > 0) {
491 list_for_each_entry(tmp, &ops->rules_list, list) {
492 if (rtnl_dereference(tmp->ctarget) == rule) {
493 rcu_assign_pointer(tmp->ctarget, NULL);
494 ops->unresolved_rules++;
495 }
496 }
497 }
498
499 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
500 NETLINK_CB(skb).pid);
501 fib_rule_put(rule);
502 flush_route_cache(ops);
503 rules_ops_put(ops);
504 return 0;
505 }
506
507 err = -ENOENT;
508errout:
509 rules_ops_put(ops);
510 return err;
511}
512
513static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
514 struct fib_rule *rule)
515{
516 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
517 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
518 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
519 + nla_total_size(4) /* FRA_PRIORITY */
520 + nla_total_size(4) /* FRA_TABLE */
521 + nla_total_size(4) /* FRA_FWMARK */
522 + nla_total_size(4); /* FRA_FWMASK */
523
524 if (ops->nlmsg_payload)
525 payload += ops->nlmsg_payload(rule);
526
527 return payload;
528}
529
530static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
531 u32 pid, u32 seq, int type, int flags,
532 struct fib_rules_ops *ops)
533{
534 struct nlmsghdr *nlh;
535 struct fib_rule_hdr *frh;
536
537 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
538 if (nlh == NULL)
539 return -EMSGSIZE;
540
541 frh = nlmsg_data(nlh);
542 frh->family = ops->family;
543 frh->table = rule->table;
544 NLA_PUT_U32(skb, FRA_TABLE, rule->table);
545 frh->res1 = 0;
546 frh->res2 = 0;
547 frh->action = rule->action;
548 frh->flags = rule->flags;
549
550 if (rule->action == FR_ACT_GOTO &&
551 rcu_dereference_raw(rule->ctarget) == NULL)
552 frh->flags |= FIB_RULE_UNRESOLVED;
553
554 if (rule->iifname[0]) {
555 NLA_PUT_STRING(skb, FRA_IIFNAME, rule->iifname);
556
557 if (rule->iifindex == -1)
558 frh->flags |= FIB_RULE_IIF_DETACHED;
559 }
560
561 if (rule->oifname[0]) {
562 NLA_PUT_STRING(skb, FRA_OIFNAME, rule->oifname);
563
564 if (rule->oifindex == -1)
565 frh->flags |= FIB_RULE_OIF_DETACHED;
566 }
567
568 if (rule->pref)
569 NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
570
571 if (rule->mark)
572 NLA_PUT_U32(skb, FRA_FWMARK, rule->mark);
573
574 if (rule->mark_mask || rule->mark)
575 NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask);
576
577 if (rule->target)
578 NLA_PUT_U32(skb, FRA_GOTO, rule->target);
579
580 if (ops->fill(rule, skb, frh) < 0)
581 goto nla_put_failure;
582
583 return nlmsg_end(skb, nlh);
584
585nla_put_failure:
586 nlmsg_cancel(skb, nlh);
587 return -EMSGSIZE;
588}
589
590static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
591 struct fib_rules_ops *ops)
592{
593 int idx = 0;
594 struct fib_rule *rule;
595
596 rcu_read_lock();
597 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
598 if (idx < cb->args[1])
599 goto skip;
600
601 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
602 cb->nlh->nlmsg_seq, RTM_NEWRULE,
603 NLM_F_MULTI, ops) < 0)
604 break;
605skip:
606 idx++;
607 }
608 rcu_read_unlock();
609 cb->args[1] = idx;
610 rules_ops_put(ops);
611
612 return skb->len;
613}
614
615static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
616{
617 struct net *net = sock_net(skb->sk);
618 struct fib_rules_ops *ops;
619 int idx = 0, family;
620
621 family = rtnl_msg_family(cb->nlh);
622 if (family != AF_UNSPEC) {
623 /* Protocol specific dump request */
624 ops = lookup_rules_ops(net, family);
625 if (ops == NULL)
626 return -EAFNOSUPPORT;
627
628 return dump_rules(skb, cb, ops);
629 }
630
631 rcu_read_lock();
632 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
633 if (idx < cb->args[0] || !try_module_get(ops->owner))
634 goto skip;
635
636 if (dump_rules(skb, cb, ops) < 0)
637 break;
638
639 cb->args[1] = 0;
640skip:
641 idx++;
642 }
643 rcu_read_unlock();
644 cb->args[0] = idx;
645
646 return skb->len;
647}
648
649static void notify_rule_change(int event, struct fib_rule *rule,
650 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
651 u32 pid)
652{
653 struct net *net;
654 struct sk_buff *skb;
655 int err = -ENOBUFS;
656
657 net = ops->fro_net;
658 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
659 if (skb == NULL)
660 goto errout;
661
662 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
663 if (err < 0) {
664 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
665 WARN_ON(err == -EMSGSIZE);
666 kfree_skb(skb);
667 goto errout;
668 }
669
670 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
671 return;
672errout:
673 if (err < 0)
674 rtnl_set_sk_err(net, ops->nlgroup, err);
675}
676
677static void attach_rules(struct list_head *rules, struct net_device *dev)
678{
679 struct fib_rule *rule;
680
681 list_for_each_entry(rule, rules, list) {
682 if (rule->iifindex == -1 &&
683 strcmp(dev->name, rule->iifname) == 0)
684 rule->iifindex = dev->ifindex;
685 if (rule->oifindex == -1 &&
686 strcmp(dev->name, rule->oifname) == 0)
687 rule->oifindex = dev->ifindex;
688 }
689}
690
691static void detach_rules(struct list_head *rules, struct net_device *dev)
692{
693 struct fib_rule *rule;
694
695 list_for_each_entry(rule, rules, list) {
696 if (rule->iifindex == dev->ifindex)
697 rule->iifindex = -1;
698 if (rule->oifindex == dev->ifindex)
699 rule->oifindex = -1;
700 }
701}
702
703
704static int fib_rules_event(struct notifier_block *this, unsigned long event,
705 void *ptr)
706{
707 struct net_device *dev = ptr;
708 struct net *net = dev_net(dev);
709 struct fib_rules_ops *ops;
710
711 ASSERT_RTNL();
712
713 switch (event) {
714 case NETDEV_REGISTER:
715 list_for_each_entry(ops, &net->rules_ops, list)
716 attach_rules(&ops->rules_list, dev);
717 break;
718
719 case NETDEV_UNREGISTER:
720 list_for_each_entry(ops, &net->rules_ops, list)
721 detach_rules(&ops->rules_list, dev);
722 break;
723 }
724
725 return NOTIFY_DONE;
726}
727
728static struct notifier_block fib_rules_notifier = {
729 .notifier_call = fib_rules_event,
730};
731
732static int __net_init fib_rules_net_init(struct net *net)
733{
734 INIT_LIST_HEAD(&net->rules_ops);
735 spin_lock_init(&net->rules_mod_lock);
736 return 0;
737}
738
739static struct pernet_operations fib_rules_net_ops = {
740 .init = fib_rules_net_init,
741};
742
743static int __init fib_rules_init(void)
744{
745 int err;
746 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
747 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
748 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
749
750 err = register_pernet_subsys(&fib_rules_net_ops);
751 if (err < 0)
752 goto fail;
753
754 err = register_netdevice_notifier(&fib_rules_notifier);
755 if (err < 0)
756 goto fail_unregister;
757
758 return 0;
759
760fail_unregister:
761 unregister_pernet_subsys(&fib_rules_net_ops);
762fail:
763 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
764 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
765 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
766 return err;
767}
768
769subsys_initcall(fib_rules_init);