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gen_stats: Fix netlink stats dumping in the presence of padding
[mirror_ubuntu-bionic-kernel.git] / net / core / fib_rules.c
1 /*
2 * net/core/fib_rules.c Generic Routing Rules
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation, version 2.
7 *
8 * Authors: Thomas Graf <tgraf@suug.ch>
9 */
10
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/list.h>
15 #include <linux/module.h>
16 #include <net/net_namespace.h>
17 #include <net/sock.h>
18 #include <net/fib_rules.h>
19 #include <net/ip_tunnels.h>
20
21 static const struct fib_kuid_range fib_kuid_range_unset = {
22 KUIDT_INIT(0),
23 KUIDT_INIT(~0),
24 };
25
26 bool fib_rule_matchall(const struct fib_rule *rule)
27 {
28 if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
29 rule->flags)
30 return false;
31 if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
32 return false;
33 if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
34 !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
35 return false;
36 return true;
37 }
38 EXPORT_SYMBOL_GPL(fib_rule_matchall);
39
40 int fib_default_rule_add(struct fib_rules_ops *ops,
41 u32 pref, u32 table, u32 flags)
42 {
43 struct fib_rule *r;
44
45 r = kzalloc(ops->rule_size, GFP_KERNEL);
46 if (r == NULL)
47 return -ENOMEM;
48
49 refcount_set(&r->refcnt, 1);
50 r->action = FR_ACT_TO_TBL;
51 r->pref = pref;
52 r->table = table;
53 r->flags = flags;
54 r->fr_net = ops->fro_net;
55 r->uid_range = fib_kuid_range_unset;
56
57 r->suppress_prefixlen = -1;
58 r->suppress_ifgroup = -1;
59
60 /* The lock is not required here, the list in unreacheable
61 * at the moment this function is called */
62 list_add_tail(&r->list, &ops->rules_list);
63 return 0;
64 }
65 EXPORT_SYMBOL(fib_default_rule_add);
66
67 static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
68 {
69 struct list_head *pos;
70 struct fib_rule *rule;
71
72 if (!list_empty(&ops->rules_list)) {
73 pos = ops->rules_list.next;
74 if (pos->next != &ops->rules_list) {
75 rule = list_entry(pos->next, struct fib_rule, list);
76 if (rule->pref)
77 return rule->pref - 1;
78 }
79 }
80
81 return 0;
82 }
83
84 static void notify_rule_change(int event, struct fib_rule *rule,
85 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
86 u32 pid);
87
88 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
89 {
90 struct fib_rules_ops *ops;
91
92 rcu_read_lock();
93 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
94 if (ops->family == family) {
95 if (!try_module_get(ops->owner))
96 ops = NULL;
97 rcu_read_unlock();
98 return ops;
99 }
100 }
101 rcu_read_unlock();
102
103 return NULL;
104 }
105
106 static void rules_ops_put(struct fib_rules_ops *ops)
107 {
108 if (ops)
109 module_put(ops->owner);
110 }
111
112 static void flush_route_cache(struct fib_rules_ops *ops)
113 {
114 if (ops->flush_cache)
115 ops->flush_cache(ops);
116 }
117
118 static int __fib_rules_register(struct fib_rules_ops *ops)
119 {
120 int err = -EEXIST;
121 struct fib_rules_ops *o;
122 struct net *net;
123
124 net = ops->fro_net;
125
126 if (ops->rule_size < sizeof(struct fib_rule))
127 return -EINVAL;
128
129 if (ops->match == NULL || ops->configure == NULL ||
130 ops->compare == NULL || ops->fill == NULL ||
131 ops->action == NULL)
132 return -EINVAL;
133
134 spin_lock(&net->rules_mod_lock);
135 list_for_each_entry(o, &net->rules_ops, list)
136 if (ops->family == o->family)
137 goto errout;
138
139 list_add_tail_rcu(&ops->list, &net->rules_ops);
140 err = 0;
141 errout:
142 spin_unlock(&net->rules_mod_lock);
143
144 return err;
145 }
146
147 struct fib_rules_ops *
148 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
149 {
150 struct fib_rules_ops *ops;
151 int err;
152
153 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
154 if (ops == NULL)
155 return ERR_PTR(-ENOMEM);
156
157 INIT_LIST_HEAD(&ops->rules_list);
158 ops->fro_net = net;
159
160 err = __fib_rules_register(ops);
161 if (err) {
162 kfree(ops);
163 ops = ERR_PTR(err);
164 }
165
166 return ops;
167 }
168 EXPORT_SYMBOL_GPL(fib_rules_register);
169
170 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
171 {
172 struct fib_rule *rule, *tmp;
173
174 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
175 list_del_rcu(&rule->list);
176 if (ops->delete)
177 ops->delete(rule);
178 fib_rule_put(rule);
179 }
180 }
181
182 void fib_rules_unregister(struct fib_rules_ops *ops)
183 {
184 struct net *net = ops->fro_net;
185
186 spin_lock(&net->rules_mod_lock);
187 list_del_rcu(&ops->list);
188 spin_unlock(&net->rules_mod_lock);
189
190 fib_rules_cleanup_ops(ops);
191 kfree_rcu(ops, rcu);
192 }
193 EXPORT_SYMBOL_GPL(fib_rules_unregister);
194
195 static int uid_range_set(struct fib_kuid_range *range)
196 {
197 return uid_valid(range->start) && uid_valid(range->end);
198 }
199
200 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
201 {
202 struct fib_rule_uid_range *in;
203 struct fib_kuid_range out;
204
205 in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
206
207 out.start = make_kuid(current_user_ns(), in->start);
208 out.end = make_kuid(current_user_ns(), in->end);
209
210 return out;
211 }
212
213 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
214 {
215 struct fib_rule_uid_range out = {
216 from_kuid_munged(current_user_ns(), range->start),
217 from_kuid_munged(current_user_ns(), range->end)
218 };
219
220 return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
221 }
222
223 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
224 struct flowi *fl, int flags,
225 struct fib_lookup_arg *arg)
226 {
227 int ret = 0;
228
229 if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
230 goto out;
231
232 if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
233 goto out;
234
235 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
236 goto out;
237
238 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
239 goto out;
240
241 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
242 goto out;
243
244 if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
245 uid_gt(fl->flowi_uid, rule->uid_range.end))
246 goto out;
247
248 ret = ops->match(rule, fl, flags);
249 out:
250 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
251 }
252
253 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
254 int flags, struct fib_lookup_arg *arg)
255 {
256 struct fib_rule *rule;
257 int err;
258
259 rcu_read_lock();
260
261 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
262 jumped:
263 if (!fib_rule_match(rule, ops, fl, flags, arg))
264 continue;
265
266 if (rule->action == FR_ACT_GOTO) {
267 struct fib_rule *target;
268
269 target = rcu_dereference(rule->ctarget);
270 if (target == NULL) {
271 continue;
272 } else {
273 rule = target;
274 goto jumped;
275 }
276 } else if (rule->action == FR_ACT_NOP)
277 continue;
278 else
279 err = ops->action(rule, fl, flags, arg);
280
281 if (!err && ops->suppress && ops->suppress(rule, arg))
282 continue;
283
284 if (err != -EAGAIN) {
285 if ((arg->flags & FIB_LOOKUP_NOREF) ||
286 likely(refcount_inc_not_zero(&rule->refcnt))) {
287 arg->rule = rule;
288 goto out;
289 }
290 break;
291 }
292 }
293
294 err = -ESRCH;
295 out:
296 rcu_read_unlock();
297
298 return err;
299 }
300 EXPORT_SYMBOL_GPL(fib_rules_lookup);
301
302 static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
303 enum fib_event_type event_type,
304 struct fib_rule *rule, int family)
305 {
306 struct fib_rule_notifier_info info = {
307 .info.family = family,
308 .rule = rule,
309 };
310
311 return call_fib_notifier(nb, net, event_type, &info.info);
312 }
313
314 static int call_fib_rule_notifiers(struct net *net,
315 enum fib_event_type event_type,
316 struct fib_rule *rule,
317 struct fib_rules_ops *ops,
318 struct netlink_ext_ack *extack)
319 {
320 struct fib_rule_notifier_info info = {
321 .info.family = ops->family,
322 .info.extack = extack,
323 .rule = rule,
324 };
325
326 ops->fib_rules_seq++;
327 return call_fib_notifiers(net, event_type, &info.info);
328 }
329
330 /* Called with rcu_read_lock() */
331 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family)
332 {
333 struct fib_rules_ops *ops;
334 struct fib_rule *rule;
335
336 ops = lookup_rules_ops(net, family);
337 if (!ops)
338 return -EAFNOSUPPORT;
339 list_for_each_entry_rcu(rule, &ops->rules_list, list)
340 call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule,
341 family);
342 rules_ops_put(ops);
343
344 return 0;
345 }
346 EXPORT_SYMBOL_GPL(fib_rules_dump);
347
348 unsigned int fib_rules_seq_read(struct net *net, int family)
349 {
350 unsigned int fib_rules_seq;
351 struct fib_rules_ops *ops;
352
353 ASSERT_RTNL();
354
355 ops = lookup_rules_ops(net, family);
356 if (!ops)
357 return 0;
358 fib_rules_seq = ops->fib_rules_seq;
359 rules_ops_put(ops);
360
361 return fib_rules_seq;
362 }
363 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
364
365 static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
366 struct fib_rules_ops *ops)
367 {
368 int err = -EINVAL;
369
370 if (frh->src_len)
371 if (tb[FRA_SRC] == NULL ||
372 frh->src_len > (ops->addr_size * 8) ||
373 nla_len(tb[FRA_SRC]) != ops->addr_size)
374 goto errout;
375
376 if (frh->dst_len)
377 if (tb[FRA_DST] == NULL ||
378 frh->dst_len > (ops->addr_size * 8) ||
379 nla_len(tb[FRA_DST]) != ops->addr_size)
380 goto errout;
381
382 err = 0;
383 errout:
384 return err;
385 }
386
387 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
388 struct nlattr **tb, struct fib_rule *rule)
389 {
390 struct fib_rule *r;
391
392 list_for_each_entry(r, &ops->rules_list, list) {
393 if (r->action != rule->action)
394 continue;
395
396 if (r->table != rule->table)
397 continue;
398
399 if (r->pref != rule->pref)
400 continue;
401
402 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
403 continue;
404
405 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
406 continue;
407
408 if (r->mark != rule->mark)
409 continue;
410
411 if (r->mark_mask != rule->mark_mask)
412 continue;
413
414 if (r->tun_id != rule->tun_id)
415 continue;
416
417 if (r->fr_net != rule->fr_net)
418 continue;
419
420 if (r->l3mdev != rule->l3mdev)
421 continue;
422
423 if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
424 !uid_eq(r->uid_range.end, rule->uid_range.end))
425 continue;
426
427 if (!ops->compare(r, frh, tb))
428 continue;
429 return 1;
430 }
431 return 0;
432 }
433
434 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
435 struct netlink_ext_ack *extack)
436 {
437 struct net *net = sock_net(skb->sk);
438 struct fib_rule_hdr *frh = nlmsg_data(nlh);
439 struct fib_rules_ops *ops = NULL;
440 struct fib_rule *rule, *r, *last = NULL;
441 struct nlattr *tb[FRA_MAX+1];
442 int err = -EINVAL, unresolved = 0;
443
444 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
445 goto errout;
446
447 ops = lookup_rules_ops(net, frh->family);
448 if (ops == NULL) {
449 err = -EAFNOSUPPORT;
450 goto errout;
451 }
452
453 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
454 if (err < 0)
455 goto errout;
456
457 err = validate_rulemsg(frh, tb, ops);
458 if (err < 0)
459 goto errout;
460
461 rule = kzalloc(ops->rule_size, GFP_KERNEL);
462 if (rule == NULL) {
463 err = -ENOMEM;
464 goto errout;
465 }
466 refcount_set(&rule->refcnt, 1);
467 rule->fr_net = net;
468
469 rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
470 : fib_default_rule_pref(ops);
471
472 if (tb[FRA_IIFNAME]) {
473 struct net_device *dev;
474
475 rule->iifindex = -1;
476 nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
477 dev = __dev_get_by_name(net, rule->iifname);
478 if (dev)
479 rule->iifindex = dev->ifindex;
480 }
481
482 if (tb[FRA_OIFNAME]) {
483 struct net_device *dev;
484
485 rule->oifindex = -1;
486 nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
487 dev = __dev_get_by_name(net, rule->oifname);
488 if (dev)
489 rule->oifindex = dev->ifindex;
490 }
491
492 if (tb[FRA_FWMARK]) {
493 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
494 if (rule->mark)
495 /* compatibility: if the mark value is non-zero all bits
496 * are compared unless a mask is explicitly specified.
497 */
498 rule->mark_mask = 0xFFFFFFFF;
499 }
500
501 if (tb[FRA_FWMASK])
502 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
503
504 if (tb[FRA_TUN_ID])
505 rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
506
507 err = -EINVAL;
508 if (tb[FRA_L3MDEV]) {
509 #ifdef CONFIG_NET_L3_MASTER_DEV
510 rule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]);
511 if (rule->l3mdev != 1)
512 #endif
513 goto errout_free;
514 }
515
516 rule->action = frh->action;
517 rule->flags = frh->flags;
518 rule->table = frh_get_table(frh, tb);
519 if (tb[FRA_SUPPRESS_PREFIXLEN])
520 rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
521 else
522 rule->suppress_prefixlen = -1;
523
524 if (tb[FRA_SUPPRESS_IFGROUP])
525 rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
526 else
527 rule->suppress_ifgroup = -1;
528
529 if (tb[FRA_GOTO]) {
530 if (rule->action != FR_ACT_GOTO)
531 goto errout_free;
532
533 rule->target = nla_get_u32(tb[FRA_GOTO]);
534 /* Backward jumps are prohibited to avoid endless loops */
535 if (rule->target <= rule->pref)
536 goto errout_free;
537
538 list_for_each_entry(r, &ops->rules_list, list) {
539 if (r->pref == rule->target) {
540 RCU_INIT_POINTER(rule->ctarget, r);
541 break;
542 }
543 }
544
545 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
546 unresolved = 1;
547 } else if (rule->action == FR_ACT_GOTO)
548 goto errout_free;
549
550 if (rule->l3mdev && rule->table)
551 goto errout_free;
552
553 if (tb[FRA_UID_RANGE]) {
554 if (current_user_ns() != net->user_ns) {
555 err = -EPERM;
556 goto errout_free;
557 }
558
559 rule->uid_range = nla_get_kuid_range(tb);
560
561 if (!uid_range_set(&rule->uid_range) ||
562 !uid_lte(rule->uid_range.start, rule->uid_range.end))
563 goto errout_free;
564 } else {
565 rule->uid_range = fib_kuid_range_unset;
566 }
567
568 if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
569 rule_exists(ops, frh, tb, rule)) {
570 err = -EEXIST;
571 goto errout_free;
572 }
573
574 err = ops->configure(rule, skb, frh, tb);
575 if (err < 0)
576 goto errout_free;
577
578 list_for_each_entry(r, &ops->rules_list, list) {
579 if (r->pref > rule->pref)
580 break;
581 last = r;
582 }
583
584 if (last)
585 list_add_rcu(&rule->list, &last->list);
586 else
587 list_add_rcu(&rule->list, &ops->rules_list);
588
589 if (ops->unresolved_rules) {
590 /*
591 * There are unresolved goto rules in the list, check if
592 * any of them are pointing to this new rule.
593 */
594 list_for_each_entry(r, &ops->rules_list, list) {
595 if (r->action == FR_ACT_GOTO &&
596 r->target == rule->pref &&
597 rtnl_dereference(r->ctarget) == NULL) {
598 rcu_assign_pointer(r->ctarget, rule);
599 if (--ops->unresolved_rules == 0)
600 break;
601 }
602 }
603 }
604
605 if (rule->action == FR_ACT_GOTO)
606 ops->nr_goto_rules++;
607
608 if (unresolved)
609 ops->unresolved_rules++;
610
611 if (rule->tun_id)
612 ip_tunnel_need_metadata();
613
614 call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, extack);
615 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
616 flush_route_cache(ops);
617 rules_ops_put(ops);
618 return 0;
619
620 errout_free:
621 kfree(rule);
622 errout:
623 rules_ops_put(ops);
624 return err;
625 }
626 EXPORT_SYMBOL_GPL(fib_nl_newrule);
627
628 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
629 struct netlink_ext_ack *extack)
630 {
631 struct net *net = sock_net(skb->sk);
632 struct fib_rule_hdr *frh = nlmsg_data(nlh);
633 struct fib_rules_ops *ops = NULL;
634 struct fib_rule *rule, *r;
635 struct nlattr *tb[FRA_MAX+1];
636 struct fib_kuid_range range;
637 int err = -EINVAL;
638
639 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
640 goto errout;
641
642 ops = lookup_rules_ops(net, frh->family);
643 if (ops == NULL) {
644 err = -EAFNOSUPPORT;
645 goto errout;
646 }
647
648 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
649 if (err < 0)
650 goto errout;
651
652 err = validate_rulemsg(frh, tb, ops);
653 if (err < 0)
654 goto errout;
655
656 if (tb[FRA_UID_RANGE]) {
657 range = nla_get_kuid_range(tb);
658 if (!uid_range_set(&range)) {
659 err = -EINVAL;
660 goto errout;
661 }
662 } else {
663 range = fib_kuid_range_unset;
664 }
665
666 list_for_each_entry(rule, &ops->rules_list, list) {
667 if (frh->action && (frh->action != rule->action))
668 continue;
669
670 if (frh_get_table(frh, tb) &&
671 (frh_get_table(frh, tb) != rule->table))
672 continue;
673
674 if (tb[FRA_PRIORITY] &&
675 (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
676 continue;
677
678 if (tb[FRA_IIFNAME] &&
679 nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
680 continue;
681
682 if (tb[FRA_OIFNAME] &&
683 nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
684 continue;
685
686 if (tb[FRA_FWMARK] &&
687 (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
688 continue;
689
690 if (tb[FRA_FWMASK] &&
691 (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
692 continue;
693
694 if (tb[FRA_TUN_ID] &&
695 (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID])))
696 continue;
697
698 if (tb[FRA_L3MDEV] &&
699 (rule->l3mdev != nla_get_u8(tb[FRA_L3MDEV])))
700 continue;
701
702 if (uid_range_set(&range) &&
703 (!uid_eq(rule->uid_range.start, range.start) ||
704 !uid_eq(rule->uid_range.end, range.end)))
705 continue;
706
707 if (!ops->compare(rule, frh, tb))
708 continue;
709
710 if (rule->flags & FIB_RULE_PERMANENT) {
711 err = -EPERM;
712 goto errout;
713 }
714
715 if (ops->delete) {
716 err = ops->delete(rule);
717 if (err)
718 goto errout;
719 }
720
721 if (rule->tun_id)
722 ip_tunnel_unneed_metadata();
723
724 list_del_rcu(&rule->list);
725
726 if (rule->action == FR_ACT_GOTO) {
727 ops->nr_goto_rules--;
728 if (rtnl_dereference(rule->ctarget) == NULL)
729 ops->unresolved_rules--;
730 }
731
732 /*
733 * Check if this rule is a target to any of them. If so,
734 * adjust to the next one with the same preference or
735 * disable them. As this operation is eventually very
736 * expensive, it is only performed if goto rules, except
737 * current if it is goto rule, have actually been added.
738 */
739 if (ops->nr_goto_rules > 0) {
740 struct fib_rule *n;
741
742 n = list_next_entry(rule, list);
743 if (&n->list == &ops->rules_list || n->pref != rule->pref)
744 n = NULL;
745 list_for_each_entry(r, &ops->rules_list, list) {
746 if (rtnl_dereference(r->ctarget) != rule)
747 continue;
748 rcu_assign_pointer(r->ctarget, n);
749 if (!n)
750 ops->unresolved_rules++;
751 }
752 }
753
754 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
755 NULL);
756 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
757 NETLINK_CB(skb).portid);
758 fib_rule_put(rule);
759 flush_route_cache(ops);
760 rules_ops_put(ops);
761 return 0;
762 }
763
764 err = -ENOENT;
765 errout:
766 rules_ops_put(ops);
767 return err;
768 }
769 EXPORT_SYMBOL_GPL(fib_nl_delrule);
770
771 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
772 struct fib_rule *rule)
773 {
774 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
775 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
776 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
777 + nla_total_size(4) /* FRA_PRIORITY */
778 + nla_total_size(4) /* FRA_TABLE */
779 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
780 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
781 + nla_total_size(4) /* FRA_FWMARK */
782 + nla_total_size(4) /* FRA_FWMASK */
783 + nla_total_size_64bit(8) /* FRA_TUN_ID */
784 + nla_total_size(sizeof(struct fib_kuid_range));
785
786 if (ops->nlmsg_payload)
787 payload += ops->nlmsg_payload(rule);
788
789 return payload;
790 }
791
792 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
793 u32 pid, u32 seq, int type, int flags,
794 struct fib_rules_ops *ops)
795 {
796 struct nlmsghdr *nlh;
797 struct fib_rule_hdr *frh;
798
799 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
800 if (nlh == NULL)
801 return -EMSGSIZE;
802
803 frh = nlmsg_data(nlh);
804 frh->family = ops->family;
805 frh->table = rule->table;
806 if (nla_put_u32(skb, FRA_TABLE, rule->table))
807 goto nla_put_failure;
808 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
809 goto nla_put_failure;
810 frh->res1 = 0;
811 frh->res2 = 0;
812 frh->action = rule->action;
813 frh->flags = rule->flags;
814
815 if (rule->action == FR_ACT_GOTO &&
816 rcu_access_pointer(rule->ctarget) == NULL)
817 frh->flags |= FIB_RULE_UNRESOLVED;
818
819 if (rule->iifname[0]) {
820 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
821 goto nla_put_failure;
822 if (rule->iifindex == -1)
823 frh->flags |= FIB_RULE_IIF_DETACHED;
824 }
825
826 if (rule->oifname[0]) {
827 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
828 goto nla_put_failure;
829 if (rule->oifindex == -1)
830 frh->flags |= FIB_RULE_OIF_DETACHED;
831 }
832
833 if ((rule->pref &&
834 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
835 (rule->mark &&
836 nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
837 ((rule->mark_mask || rule->mark) &&
838 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
839 (rule->target &&
840 nla_put_u32(skb, FRA_GOTO, rule->target)) ||
841 (rule->tun_id &&
842 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
843 (rule->l3mdev &&
844 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
845 (uid_range_set(&rule->uid_range) &&
846 nla_put_uid_range(skb, &rule->uid_range)))
847 goto nla_put_failure;
848
849 if (rule->suppress_ifgroup != -1) {
850 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
851 goto nla_put_failure;
852 }
853
854 if (ops->fill(rule, skb, frh) < 0)
855 goto nla_put_failure;
856
857 nlmsg_end(skb, nlh);
858 return 0;
859
860 nla_put_failure:
861 nlmsg_cancel(skb, nlh);
862 return -EMSGSIZE;
863 }
864
865 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
866 struct fib_rules_ops *ops)
867 {
868 int idx = 0;
869 struct fib_rule *rule;
870 int err = 0;
871
872 rcu_read_lock();
873 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
874 if (idx < cb->args[1])
875 goto skip;
876
877 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
878 cb->nlh->nlmsg_seq, RTM_NEWRULE,
879 NLM_F_MULTI, ops);
880 if (err)
881 break;
882 skip:
883 idx++;
884 }
885 rcu_read_unlock();
886 cb->args[1] = idx;
887 rules_ops_put(ops);
888
889 return err;
890 }
891
892 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
893 {
894 struct net *net = sock_net(skb->sk);
895 struct fib_rules_ops *ops;
896 int idx = 0, family;
897
898 family = rtnl_msg_family(cb->nlh);
899 if (family != AF_UNSPEC) {
900 /* Protocol specific dump request */
901 ops = lookup_rules_ops(net, family);
902 if (ops == NULL)
903 return -EAFNOSUPPORT;
904
905 dump_rules(skb, cb, ops);
906
907 return skb->len;
908 }
909
910 rcu_read_lock();
911 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
912 if (idx < cb->args[0] || !try_module_get(ops->owner))
913 goto skip;
914
915 if (dump_rules(skb, cb, ops) < 0)
916 break;
917
918 cb->args[1] = 0;
919 skip:
920 idx++;
921 }
922 rcu_read_unlock();
923 cb->args[0] = idx;
924
925 return skb->len;
926 }
927
928 static void notify_rule_change(int event, struct fib_rule *rule,
929 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
930 u32 pid)
931 {
932 struct net *net;
933 struct sk_buff *skb;
934 int err = -ENOBUFS;
935
936 net = ops->fro_net;
937 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
938 if (skb == NULL)
939 goto errout;
940
941 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
942 if (err < 0) {
943 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
944 WARN_ON(err == -EMSGSIZE);
945 kfree_skb(skb);
946 goto errout;
947 }
948
949 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
950 return;
951 errout:
952 if (err < 0)
953 rtnl_set_sk_err(net, ops->nlgroup, err);
954 }
955
956 static void attach_rules(struct list_head *rules, struct net_device *dev)
957 {
958 struct fib_rule *rule;
959
960 list_for_each_entry(rule, rules, list) {
961 if (rule->iifindex == -1 &&
962 strcmp(dev->name, rule->iifname) == 0)
963 rule->iifindex = dev->ifindex;
964 if (rule->oifindex == -1 &&
965 strcmp(dev->name, rule->oifname) == 0)
966 rule->oifindex = dev->ifindex;
967 }
968 }
969
970 static void detach_rules(struct list_head *rules, struct net_device *dev)
971 {
972 struct fib_rule *rule;
973
974 list_for_each_entry(rule, rules, list) {
975 if (rule->iifindex == dev->ifindex)
976 rule->iifindex = -1;
977 if (rule->oifindex == dev->ifindex)
978 rule->oifindex = -1;
979 }
980 }
981
982
983 static int fib_rules_event(struct notifier_block *this, unsigned long event,
984 void *ptr)
985 {
986 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
987 struct net *net = dev_net(dev);
988 struct fib_rules_ops *ops;
989
990 ASSERT_RTNL();
991
992 switch (event) {
993 case NETDEV_REGISTER:
994 list_for_each_entry(ops, &net->rules_ops, list)
995 attach_rules(&ops->rules_list, dev);
996 break;
997
998 case NETDEV_CHANGENAME:
999 list_for_each_entry(ops, &net->rules_ops, list) {
1000 detach_rules(&ops->rules_list, dev);
1001 attach_rules(&ops->rules_list, dev);
1002 }
1003 break;
1004
1005 case NETDEV_UNREGISTER:
1006 list_for_each_entry(ops, &net->rules_ops, list)
1007 detach_rules(&ops->rules_list, dev);
1008 break;
1009 }
1010
1011 return NOTIFY_DONE;
1012 }
1013
1014 static struct notifier_block fib_rules_notifier = {
1015 .notifier_call = fib_rules_event,
1016 };
1017
1018 static int __net_init fib_rules_net_init(struct net *net)
1019 {
1020 INIT_LIST_HEAD(&net->rules_ops);
1021 spin_lock_init(&net->rules_mod_lock);
1022 return 0;
1023 }
1024
1025 static void __net_exit fib_rules_net_exit(struct net *net)
1026 {
1027 WARN_ON_ONCE(!list_empty(&net->rules_ops));
1028 }
1029
1030 static struct pernet_operations fib_rules_net_ops = {
1031 .init = fib_rules_net_init,
1032 .exit = fib_rules_net_exit,
1033 };
1034
1035 static int __init fib_rules_init(void)
1036 {
1037 int err;
1038 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1039 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1040 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1041
1042 err = register_pernet_subsys(&fib_rules_net_ops);
1043 if (err < 0)
1044 goto fail;
1045
1046 err = register_netdevice_notifier(&fib_rules_notifier);
1047 if (err < 0)
1048 goto fail_unregister;
1049
1050 return 0;
1051
1052 fail_unregister:
1053 unregister_pernet_subsys(&fib_rules_net_ops);
1054 fail:
1055 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1056 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1057 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1058 return err;
1059 }
1060
1061 subsys_initcall(fib_rules_init);
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