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11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/list.h>
15#include <linux/module.h>
16#include <net/net_namespace.h>
17#include <net/sock.h>
18#include <net/fib_rules.h>
19
20int fib_default_rule_add(struct fib_rules_ops *ops,
21 u32 pref, u32 table, u32 flags)
22{
23 struct fib_rule *r;
24
25 r = kzalloc(ops->rule_size, GFP_KERNEL);
26 if (r == NULL)
27 return -ENOMEM;
28
29 atomic_set(&r->refcnt, 1);
30 r->action = FR_ACT_TO_TBL;
31 r->pref = pref;
32 r->table = table;
33 r->flags = flags;
34 r->fr_net = hold_net(ops->fro_net);
35
36
37
38 list_add_tail(&r->list, &ops->rules_list);
39 return 0;
40}
41EXPORT_SYMBOL(fib_default_rule_add);
42
43u32 fib_default_rule_pref(struct fib_rules_ops *ops)
44{
45 struct list_head *pos;
46 struct fib_rule *rule;
47
48 if (!list_empty(&ops->rules_list)) {
49 pos = ops->rules_list.next;
50 if (pos->next != &ops->rules_list) {
51 rule = list_entry(pos->next, struct fib_rule, list);
52 if (rule->pref)
53 return rule->pref - 1;
54 }
55 }
56
57 return 0;
58}
59EXPORT_SYMBOL(fib_default_rule_pref);
60
61static void notify_rule_change(int event, struct fib_rule *rule,
62 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
63 u32 pid);
64
65static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
66{
67 struct fib_rules_ops *ops;
68
69 rcu_read_lock();
70 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
71 if (ops->family == family) {
72 if (!try_module_get(ops->owner))
73 ops = NULL;
74 rcu_read_unlock();
75 return ops;
76 }
77 }
78 rcu_read_unlock();
79
80 return NULL;
81}
82
83static void rules_ops_put(struct fib_rules_ops *ops)
84{
85 if (ops)
86 module_put(ops->owner);
87}
88
89static void flush_route_cache(struct fib_rules_ops *ops)
90{
91 if (ops->flush_cache)
92 ops->flush_cache(ops);
93}
94
95static int __fib_rules_register(struct fib_rules_ops *ops)
96{
97 int err = -EEXIST;
98 struct fib_rules_ops *o;
99 struct net *net;
100
101 net = ops->fro_net;
102
103 if (ops->rule_size < sizeof(struct fib_rule))
104 return -EINVAL;
105
106 if (ops->match == NULL || ops->configure == NULL ||
107 ops->compare == NULL || ops->fill == NULL ||
108 ops->action == NULL)
109 return -EINVAL;
110
111 spin_lock(&net->rules_mod_lock);
112 list_for_each_entry(o, &net->rules_ops, list)
113 if (ops->family == o->family)
114 goto errout;
115
116 hold_net(net);
117 list_add_tail_rcu(&ops->list, &net->rules_ops);
118 err = 0;
119errout:
120 spin_unlock(&net->rules_mod_lock);
121
122 return err;
123}
124
125struct fib_rules_ops *
126fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
127{
128 struct fib_rules_ops *ops;
129 int err;
130
131 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
132 if (ops == NULL)
133 return ERR_PTR(-ENOMEM);
134
135 INIT_LIST_HEAD(&ops->rules_list);
136 ops->fro_net = net;
137
138 err = __fib_rules_register(ops);
139 if (err) {
140 kfree(ops);
141 ops = ERR_PTR(err);
142 }
143
144 return ops;
145}
146EXPORT_SYMBOL_GPL(fib_rules_register);
147
148static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
149{
150 struct fib_rule *rule, *tmp;
151
152 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
153 list_del_rcu(&rule->list);
154 fib_rule_put(rule);
155 }
156}
157
158static void fib_rules_put_rcu(struct rcu_head *head)
159{
160 struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu);
161 struct net *net = ops->fro_net;
162
163 release_net(net);
164 kfree(ops);
165}
166
167void fib_rules_unregister(struct fib_rules_ops *ops)
168{
169 struct net *net = ops->fro_net;
170
171 spin_lock(&net->rules_mod_lock);
172 list_del_rcu(&ops->list);
173 fib_rules_cleanup_ops(ops);
174 spin_unlock(&net->rules_mod_lock);
175
176 call_rcu(&ops->rcu, fib_rules_put_rcu);
177}
178EXPORT_SYMBOL_GPL(fib_rules_unregister);
179
180static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
181 struct flowi *fl, int flags)
182{
183 int ret = 0;
184
185 if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
186 goto out;
187
188 if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
189 goto out;
190
191 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
192 goto out;
193
194 ret = ops->match(rule, fl, flags);
195out:
196 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
197}
198
199int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
200 int flags, struct fib_lookup_arg *arg)
201{
202 struct fib_rule *rule;
203 int err;
204
205 rcu_read_lock();
206
207 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
208jumped:
209 if (!fib_rule_match(rule, ops, fl, flags))
210 continue;
211
212 if (rule->action == FR_ACT_GOTO) {
213 struct fib_rule *target;
214
215 target = rcu_dereference(rule->ctarget);
216 if (target == NULL) {
217 continue;
218 } else {
219 rule = target;
220 goto jumped;
221 }
222 } else if (rule->action == FR_ACT_NOP)
223 continue;
224 else
225 err = ops->action(rule, fl, flags, arg);
226
227 if (err != -EAGAIN) {
228 if ((arg->flags & FIB_LOOKUP_NOREF) ||
229 likely(atomic_inc_not_zero(&rule->refcnt))) {
230 arg->rule = rule;
231 goto out;
232 }
233 break;
234 }
235 }
236
237 err = -ESRCH;
238out:
239 rcu_read_unlock();
240
241 return err;
242}
243EXPORT_SYMBOL_GPL(fib_rules_lookup);
244
245static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
246 struct fib_rules_ops *ops)
247{
248 int err = -EINVAL;
249
250 if (frh->src_len)
251 if (tb[FRA_SRC] == NULL ||
252 frh->src_len > (ops->addr_size * 8) ||
253 nla_len(tb[FRA_SRC]) != ops->addr_size)
254 goto errout;
255
256 if (frh->dst_len)
257 if (tb[FRA_DST] == NULL ||
258 frh->dst_len > (ops->addr_size * 8) ||
259 nla_len(tb[FRA_DST]) != ops->addr_size)
260 goto errout;
261
262 err = 0;
263errout:
264 return err;
265}
266
267static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
268{
269 struct net *net = sock_net(skb->sk);
270 struct fib_rule_hdr *frh = nlmsg_data(nlh);
271 struct fib_rules_ops *ops = NULL;
272 struct fib_rule *rule, *r, *last = NULL;
273 struct nlattr *tb[FRA_MAX+1];
274 int err = -EINVAL, unresolved = 0;
275
276 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
277 goto errout;
278
279 ops = lookup_rules_ops(net, frh->family);
280 if (ops == NULL) {
281 err = -EAFNOSUPPORT;
282 goto errout;
283 }
284
285 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
286 if (err < 0)
287 goto errout;
288
289 err = validate_rulemsg(frh, tb, ops);
290 if (err < 0)
291 goto errout;
292
293 rule = kzalloc(ops->rule_size, GFP_KERNEL);
294 if (rule == NULL) {
295 err = -ENOMEM;
296 goto errout;
297 }
298 rule->fr_net = hold_net(net);
299
300 if (tb[FRA_PRIORITY])
301 rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
302
303 if (tb[FRA_IIFNAME]) {
304 struct net_device *dev;
305
306 rule->iifindex = -1;
307 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
308 dev = __dev_get_by_name(net, rule->iifname);
309 if (dev)
310 rule->iifindex = dev->ifindex;
311 }
312
313 if (tb[FRA_OIFNAME]) {
314 struct net_device *dev;
315
316 rule->oifindex = -1;
317 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
318 dev = __dev_get_by_name(net, rule->oifname);
319 if (dev)
320 rule->oifindex = dev->ifindex;
321 }
322
323 if (tb[FRA_FWMARK]) {
324 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
325 if (rule->mark)
326
327
328
329 rule->mark_mask = 0xFFFFFFFF;
330 }
331
332 if (tb[FRA_FWMASK])
333 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
334
335 rule->action = frh->action;
336 rule->flags = frh->flags;
337 rule->table = frh_get_table(frh, tb);
338
339 if (!tb[FRA_PRIORITY] && ops->default_pref)
340 rule->pref = ops->default_pref(ops);
341
342 err = -EINVAL;
343 if (tb[FRA_GOTO]) {
344 if (rule->action != FR_ACT_GOTO)
345 goto errout_free;
346
347 rule->target = nla_get_u32(tb[FRA_GOTO]);
348
349 if (rule->target <= rule->pref)
350 goto errout_free;
351
352 list_for_each_entry(r, &ops->rules_list, list) {
353 if (r->pref == rule->target) {
354 RCU_INIT_POINTER(rule->ctarget, r);
355 break;
356 }
357 }
358
359 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
360 unresolved = 1;
361 } else if (rule->action == FR_ACT_GOTO)
362 goto errout_free;
363
364 err = ops->configure(rule, skb, frh, tb);
365 if (err < 0)
366 goto errout_free;
367
368 list_for_each_entry(r, &ops->rules_list, list) {
369 if (r->pref > rule->pref)
370 break;
371 last = r;
372 }
373
374 fib_rule_get(rule);
375
376 if (last)
377 list_add_rcu(&rule->list, &last->list);
378 else
379 list_add_rcu(&rule->list, &ops->rules_list);
380
381 if (ops->unresolved_rules) {
382
383
384
385
386 list_for_each_entry(r, &ops->rules_list, list) {
387 if (r->action == FR_ACT_GOTO &&
388 r->target == rule->pref &&
389 rtnl_dereference(r->ctarget) == NULL) {
390 rcu_assign_pointer(r->ctarget, rule);
391 if (--ops->unresolved_rules == 0)
392 break;
393 }
394 }
395 }
396
397 if (rule->action == FR_ACT_GOTO)
398 ops->nr_goto_rules++;
399
400 if (unresolved)
401 ops->unresolved_rules++;
402
403 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
404 flush_route_cache(ops);
405 rules_ops_put(ops);
406 return 0;
407
408errout_free:
409 release_net(rule->fr_net);
410 kfree(rule);
411errout:
412 rules_ops_put(ops);
413 return err;
414}
415
416static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
417{
418 struct net *net = sock_net(skb->sk);
419 struct fib_rule_hdr *frh = nlmsg_data(nlh);
420 struct fib_rules_ops *ops = NULL;
421 struct fib_rule *rule, *tmp;
422 struct nlattr *tb[FRA_MAX+1];
423 int err = -EINVAL;
424
425 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
426 goto errout;
427
428 ops = lookup_rules_ops(net, frh->family);
429 if (ops == NULL) {
430 err = -EAFNOSUPPORT;
431 goto errout;
432 }
433
434 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
435 if (err < 0)
436 goto errout;
437
438 err = validate_rulemsg(frh, tb, ops);
439 if (err < 0)
440 goto errout;
441
442 list_for_each_entry(rule, &ops->rules_list, list) {
443 if (frh->action && (frh->action != rule->action))
444 continue;
445
446 if (frh->table && (frh_get_table(frh, tb) != rule->table))
447 continue;
448
449 if (tb[FRA_PRIORITY] &&
450 (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
451 continue;
452
453 if (tb[FRA_IIFNAME] &&
454 nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
455 continue;
456
457 if (tb[FRA_OIFNAME] &&
458 nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
459 continue;
460
461 if (tb[FRA_FWMARK] &&
462 (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
463 continue;
464
465 if (tb[FRA_FWMASK] &&
466 (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
467 continue;
468
469 if (!ops->compare(rule, frh, tb))
470 continue;
471
472 if (rule->flags & FIB_RULE_PERMANENT) {
473 err = -EPERM;
474 goto errout;
475 }
476
477 list_del_rcu(&rule->list);
478
479 if (rule->action == FR_ACT_GOTO) {
480 ops->nr_goto_rules--;
481 if (rtnl_dereference(rule->ctarget) == NULL)
482 ops->unresolved_rules--;
483 }
484
485
486
487
488
489
490
491 if (ops->nr_goto_rules > 0) {
492 list_for_each_entry(tmp, &ops->rules_list, list) {
493 if (rtnl_dereference(tmp->ctarget) == rule) {
494 RCU_INIT_POINTER(tmp->ctarget, NULL);
495 ops->unresolved_rules++;
496 }
497 }
498 }
499
500 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
501 NETLINK_CB(skb).pid);
502 fib_rule_put(rule);
503 flush_route_cache(ops);
504 rules_ops_put(ops);
505 return 0;
506 }
507
508 err = -ENOENT;
509errout:
510 rules_ops_put(ops);
511 return err;
512}
513
514static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
515 struct fib_rule *rule)
516{
517 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
518 + nla_total_size(IFNAMSIZ)
519 + nla_total_size(IFNAMSIZ)
520 + nla_total_size(4)
521 + nla_total_size(4)
522 + nla_total_size(4)
523 + nla_total_size(4);
524
525 if (ops->nlmsg_payload)
526 payload += ops->nlmsg_payload(rule);
527
528 return payload;
529}
530
531static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
532 u32 pid, u32 seq, int type, int flags,
533 struct fib_rules_ops *ops)
534{
535 struct nlmsghdr *nlh;
536 struct fib_rule_hdr *frh;
537
538 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
539 if (nlh == NULL)
540 return -EMSGSIZE;
541
542 frh = nlmsg_data(nlh);
543 frh->family = ops->family;
544 frh->table = rule->table;
545 NLA_PUT_U32(skb, FRA_TABLE, rule->table);
546 frh->res1 = 0;
547 frh->res2 = 0;
548 frh->action = rule->action;
549 frh->flags = rule->flags;
550
551 if (rule->action == FR_ACT_GOTO &&
552 rcu_access_pointer(rule->ctarget) == NULL)
553 frh->flags |= FIB_RULE_UNRESOLVED;
554
555 if (rule->iifname[0]) {
556 NLA_PUT_STRING(skb, FRA_IIFNAME, rule->iifname);
557
558 if (rule->iifindex == -1)
559 frh->flags |= FIB_RULE_IIF_DETACHED;
560 }
561
562 if (rule->oifname[0]) {
563 NLA_PUT_STRING(skb, FRA_OIFNAME, rule->oifname);
564
565 if (rule->oifindex == -1)
566 frh->flags |= FIB_RULE_OIF_DETACHED;
567 }
568
569 if (rule->pref)
570 NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
571
572 if (rule->mark)
573 NLA_PUT_U32(skb, FRA_FWMARK, rule->mark);
574
575 if (rule->mark_mask || rule->mark)
576 NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask);
577
578 if (rule->target)
579 NLA_PUT_U32(skb, FRA_GOTO, rule->target);
580
581 if (ops->fill(rule, skb, frh) < 0)
582 goto nla_put_failure;
583
584 return nlmsg_end(skb, nlh);
585
586nla_put_failure:
587 nlmsg_cancel(skb, nlh);
588 return -EMSGSIZE;
589}
590
591static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
592 struct fib_rules_ops *ops)
593{
594 int idx = 0;
595 struct fib_rule *rule;
596
597 rcu_read_lock();
598 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
599 if (idx < cb->args[1])
600 goto skip;
601
602 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
603 cb->nlh->nlmsg_seq, RTM_NEWRULE,
604 NLM_F_MULTI, ops) < 0)
605 break;
606skip:
607 idx++;
608 }
609 rcu_read_unlock();
610 cb->args[1] = idx;
611 rules_ops_put(ops);
612
613 return skb->len;
614}
615
616static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
617{
618 struct net *net = sock_net(skb->sk);
619 struct fib_rules_ops *ops;
620 int idx = 0, family;
621
622 family = rtnl_msg_family(cb->nlh);
623 if (family != AF_UNSPEC) {
624
625 ops = lookup_rules_ops(net, family);
626 if (ops == NULL)
627 return -EAFNOSUPPORT;
628
629 return dump_rules(skb, cb, ops);
630 }
631
632 rcu_read_lock();
633 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
634 if (idx < cb->args[0] || !try_module_get(ops->owner))
635 goto skip;
636
637 if (dump_rules(skb, cb, ops) < 0)
638 break;
639
640 cb->args[1] = 0;
641skip:
642 idx++;
643 }
644 rcu_read_unlock();
645 cb->args[0] = idx;
646
647 return skb->len;
648}
649
650static void notify_rule_change(int event, struct fib_rule *rule,
651 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
652 u32 pid)
653{
654 struct net *net;
655 struct sk_buff *skb;
656 int err = -ENOBUFS;
657
658 net = ops->fro_net;
659 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
660 if (skb == NULL)
661 goto errout;
662
663 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
664 if (err < 0) {
665
666 WARN_ON(err == -EMSGSIZE);
667 kfree_skb(skb);
668 goto errout;
669 }
670
671 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
672 return;
673errout:
674 if (err < 0)
675 rtnl_set_sk_err(net, ops->nlgroup, err);
676}
677
678static void attach_rules(struct list_head *rules, struct net_device *dev)
679{
680 struct fib_rule *rule;
681
682 list_for_each_entry(rule, rules, list) {
683 if (rule->iifindex == -1 &&
684 strcmp(dev->name, rule->iifname) == 0)
685 rule->iifindex = dev->ifindex;
686 if (rule->oifindex == -1 &&
687 strcmp(dev->name, rule->oifname) == 0)
688 rule->oifindex = dev->ifindex;
689 }
690}
691
692static void detach_rules(struct list_head *rules, struct net_device *dev)
693{
694 struct fib_rule *rule;
695
696 list_for_each_entry(rule, rules, list) {
697 if (rule->iifindex == dev->ifindex)
698 rule->iifindex = -1;
699 if (rule->oifindex == dev->ifindex)
700 rule->oifindex = -1;
701 }
702}
703
704
705static int fib_rules_event(struct notifier_block *this, unsigned long event,
706 void *ptr)
707{
708 struct net_device *dev = ptr;
709 struct net *net = dev_net(dev);
710 struct fib_rules_ops *ops;
711
712 ASSERT_RTNL();
713
714 switch (event) {
715 case NETDEV_REGISTER:
716 list_for_each_entry(ops, &net->rules_ops, list)
717 attach_rules(&ops->rules_list, dev);
718 break;
719
720 case NETDEV_UNREGISTER:
721 list_for_each_entry(ops, &net->rules_ops, list)
722 detach_rules(&ops->rules_list, dev);
723 break;
724 }
725
726 return NOTIFY_DONE;
727}
728
729static struct notifier_block fib_rules_notifier = {
730 .notifier_call = fib_rules_event,
731};
732
733static int __net_init fib_rules_net_init(struct net *net)
734{
735 INIT_LIST_HEAD(&net->rules_ops);
736 spin_lock_init(&net->rules_mod_lock);
737 return 0;
738}
739
740static struct pernet_operations fib_rules_net_ops = {
741 .init = fib_rules_net_init,
742};
743
744static int __init fib_rules_init(void)
745{
746 int err;
747 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
748 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
749 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
750
751 err = register_pernet_subsys(&fib_rules_net_ops);
752 if (err < 0)
753 goto fail;
754
755 err = register_netdevice_notifier(&fib_rules_notifier);
756 if (err < 0)
757 goto fail_unregister;
758
759 return 0;
760
761fail_unregister:
762 unregister_pernet_subsys(&fib_rules_net_ops);
763fail:
764 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
765 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
766 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
767 return err;
768}
769
770subsys_initcall(fib_rules_init);
771
