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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 <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
36
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->iif))
185 goto out;
186
187 if (rule->oifindex && (rule->oifindex != fl->oif))
188 goto out;
189
190 if ((rule->mark ^ fl->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
326
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
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
383
384
385 list_for_each_entry(r, &ops->rules_list, list) {
386 if (r->action == FR_ACT_GOTO &&
387 r->target == rule->pref) {
388 BUG_ON(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
481
482
483
484
485
486
487 if (ops->nr_goto_rules > 0) {
488 list_for_each_entry(tmp, &ops->rules_list, list) {
489 if (rtnl_dereference(tmp->ctarget) == rule) {
490 rcu_assign_pointer(tmp->ctarget, NULL);
491 ops->unresolved_rules++;
492 }
493 }
494 }
495
496 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
497 NETLINK_CB(skb).pid);
498 fib_rule_put(rule);
499 flush_route_cache(ops);
500 rules_ops_put(ops);
501 return 0;
502 }
503
504 err = -ENOENT;
505errout:
506 rules_ops_put(ops);
507 return err;
508}
509
510static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
511 struct fib_rule *rule)
512{
513 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
514 + nla_total_size(IFNAMSIZ)
515 + nla_total_size(IFNAMSIZ)
516 + nla_total_size(4)
517 + nla_total_size(4)
518 + nla_total_size(4)
519 + nla_total_size(4);
520
521 if (ops->nlmsg_payload)
522 payload += ops->nlmsg_payload(rule);
523
524 return payload;
525}
526
527static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
528 u32 pid, u32 seq, int type, int flags,
529 struct fib_rules_ops *ops)
530{
531 struct nlmsghdr *nlh;
532 struct fib_rule_hdr *frh;
533
534 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
535 if (nlh == NULL)
536 return -EMSGSIZE;
537
538 frh = nlmsg_data(nlh);
539 frh->family = ops->family;
540 frh->table = rule->table;
541 NLA_PUT_U32(skb, FRA_TABLE, rule->table);
542 frh->res1 = 0;
543 frh->res2 = 0;
544 frh->action = rule->action;
545 frh->flags = rule->flags;
546
547 if (rule->action == FR_ACT_GOTO &&
548 rcu_dereference_raw(rule->ctarget) == NULL)
549 frh->flags |= FIB_RULE_UNRESOLVED;
550
551 if (rule->iifname[0]) {
552 NLA_PUT_STRING(skb, FRA_IIFNAME, rule->iifname);
553
554 if (rule->iifindex == -1)
555 frh->flags |= FIB_RULE_IIF_DETACHED;
556 }
557
558 if (rule->oifname[0]) {
559 NLA_PUT_STRING(skb, FRA_OIFNAME, rule->oifname);
560
561 if (rule->oifindex == -1)
562 frh->flags |= FIB_RULE_OIF_DETACHED;
563 }
564
565 if (rule->pref)
566 NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
567
568 if (rule->mark)
569 NLA_PUT_U32(skb, FRA_FWMARK, rule->mark);
570
571 if (rule->mark_mask || rule->mark)
572 NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask);
573
574 if (rule->target)
575 NLA_PUT_U32(skb, FRA_GOTO, rule->target);
576
577 if (ops->fill(rule, skb, frh) < 0)
578 goto nla_put_failure;
579
580 return nlmsg_end(skb, nlh);
581
582nla_put_failure:
583 nlmsg_cancel(skb, nlh);
584 return -EMSGSIZE;
585}
586
587static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
588 struct fib_rules_ops *ops)
589{
590 int idx = 0;
591 struct fib_rule *rule;
592
593 list_for_each_entry(rule, &ops->rules_list, list) {
594 if (idx < cb->args[1])
595 goto skip;
596
597 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
598 cb->nlh->nlmsg_seq, RTM_NEWRULE,
599 NLM_F_MULTI, ops) < 0)
600 break;
601skip:
602 idx++;
603 }
604 cb->args[1] = idx;
605 rules_ops_put(ops);
606
607 return skb->len;
608}
609
610static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
611{
612 struct net *net = sock_net(skb->sk);
613 struct fib_rules_ops *ops;
614 int idx = 0, family;
615
616 family = rtnl_msg_family(cb->nlh);
617 if (family != AF_UNSPEC) {
618
619 ops = lookup_rules_ops(net, family);
620 if (ops == NULL)
621 return -EAFNOSUPPORT;
622
623 return dump_rules(skb, cb, ops);
624 }
625
626 rcu_read_lock();
627 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
628 if (idx < cb->args[0] || !try_module_get(ops->owner))
629 goto skip;
630
631 if (dump_rules(skb, cb, ops) < 0)
632 break;
633
634 cb->args[1] = 0;
635skip:
636 idx++;
637 }
638 rcu_read_unlock();
639 cb->args[0] = idx;
640
641 return skb->len;
642}
643
644static void notify_rule_change(int event, struct fib_rule *rule,
645 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
646 u32 pid)
647{
648 struct net *net;
649 struct sk_buff *skb;
650 int err = -ENOBUFS;
651
652 net = ops->fro_net;
653 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
654 if (skb == NULL)
655 goto errout;
656
657 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
658 if (err < 0) {
659
660 WARN_ON(err == -EMSGSIZE);
661 kfree_skb(skb);
662 goto errout;
663 }
664
665 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
666 return;
667errout:
668 if (err < 0)
669 rtnl_set_sk_err(net, ops->nlgroup, err);
670}
671
672static void attach_rules(struct list_head *rules, struct net_device *dev)
673{
674 struct fib_rule *rule;
675
676 list_for_each_entry(rule, rules, list) {
677 if (rule->iifindex == -1 &&
678 strcmp(dev->name, rule->iifname) == 0)
679 rule->iifindex = dev->ifindex;
680 if (rule->oifindex == -1 &&
681 strcmp(dev->name, rule->oifname) == 0)
682 rule->oifindex = dev->ifindex;
683 }
684}
685
686static void detach_rules(struct list_head *rules, struct net_device *dev)
687{
688 struct fib_rule *rule;
689
690 list_for_each_entry(rule, rules, list) {
691 if (rule->iifindex == dev->ifindex)
692 rule->iifindex = -1;
693 if (rule->oifindex == dev->ifindex)
694 rule->oifindex = -1;
695 }
696}
697
698
699static int fib_rules_event(struct notifier_block *this, unsigned long event,
700 void *ptr)
701{
702 struct net_device *dev = ptr;
703 struct net *net = dev_net(dev);
704 struct fib_rules_ops *ops;
705
706 ASSERT_RTNL();
707
708 switch (event) {
709 case NETDEV_REGISTER:
710 list_for_each_entry(ops, &net->rules_ops, list)
711 attach_rules(&ops->rules_list, dev);
712 break;
713
714 case NETDEV_UNREGISTER:
715 list_for_each_entry(ops, &net->rules_ops, list)
716 detach_rules(&ops->rules_list, dev);
717 break;
718 }
719
720 return NOTIFY_DONE;
721}
722
723static struct notifier_block fib_rules_notifier = {
724 .notifier_call = fib_rules_event,
725};
726
727static int __net_init fib_rules_net_init(struct net *net)
728{
729 INIT_LIST_HEAD(&net->rules_ops);
730 spin_lock_init(&net->rules_mod_lock);
731 return 0;
732}
733
734static struct pernet_operations fib_rules_net_ops = {
735 .init = fib_rules_net_init,
736};
737
738static int __init fib_rules_init(void)
739{
740 int err;
741 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL);
742 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL);
743 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule);
744
745 err = register_pernet_subsys(&fib_rules_net_ops);
746 if (err < 0)
747 goto fail;
748
749 err = register_netdevice_notifier(&fib_rules_notifier);
750 if (err < 0)
751 goto fail_unregister;
752
753 return 0;
754
755fail_unregister:
756 unregister_pernet_subsys(&fib_rules_net_ops);
757fail:
758 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
759 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
760 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
761 return err;
762}
763
764subsys_initcall(fib_rules_init);
765
