xref: /linux/net/core/fib_rules.c (revision 2f435137a0484f11b47554281091ef4908f8cb31)
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/inet_dscp.h>
15 #include <net/sock.h>
16 #include <net/fib_rules.h>
17 #include <net/ip_tunnels.h>
18 #include <linux/indirect_call_wrapper.h>
19 
20 #if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES)
21 #ifdef CONFIG_IP_MULTIPLE_TABLES
22 #define INDIRECT_CALL_MT(f, f2, f1, ...) \
23 	INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__)
24 #else
25 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
26 #endif
27 #elif defined(CONFIG_IP_MULTIPLE_TABLES)
28 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
29 #else
30 #define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__)
31 #endif
32 
33 static const struct fib_kuid_range fib_kuid_range_unset = {
34 	KUIDT_INIT(0),
35 	KUIDT_INIT(~0),
36 };
37 
38 bool fib_rule_matchall(const struct fib_rule *rule)
39 {
40 	if (READ_ONCE(rule->iifindex) || READ_ONCE(rule->oifindex) ||
41 	    rule->mark || rule->tun_id || rule->flags)
42 		return false;
43 	if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
44 		return false;
45 	if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
46 	    !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
47 		return false;
48 	if (fib_rule_port_range_set(&rule->sport_range))
49 		return false;
50 	if (fib_rule_port_range_set(&rule->dport_range))
51 		return false;
52 	return true;
53 }
54 EXPORT_SYMBOL_GPL(fib_rule_matchall);
55 
56 int fib_default_rule_add(struct fib_rules_ops *ops,
57 			 u32 pref, u32 table)
58 {
59 	struct fib_rule *r;
60 
61 	r = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
62 	if (r == NULL)
63 		return -ENOMEM;
64 
65 	refcount_set(&r->refcnt, 1);
66 	r->action = FR_ACT_TO_TBL;
67 	r->pref = pref;
68 	r->table = table;
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 unreachable
77 	 * at the moment this function is called */
78 	list_add_tail(&r->list, &ops->rules_list);
79 	return 0;
80 }
81 EXPORT_SYMBOL(fib_default_rule_add);
82 
83 static 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 
100 static void notify_rule_change(int event, struct fib_rule *rule,
101 			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
102 			       u32 pid);
103 
104 static struct fib_rules_ops *lookup_rules_ops(const struct net *net,
105 					      int family)
106 {
107 	struct fib_rules_ops *ops;
108 
109 	rcu_read_lock();
110 	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
111 		if (ops->family == family) {
112 			if (!try_module_get(ops->owner))
113 				ops = NULL;
114 			rcu_read_unlock();
115 			return ops;
116 		}
117 	}
118 	rcu_read_unlock();
119 
120 	return NULL;
121 }
122 
123 static void rules_ops_put(struct fib_rules_ops *ops)
124 {
125 	if (ops)
126 		module_put(ops->owner);
127 }
128 
129 static void flush_route_cache(struct fib_rules_ops *ops)
130 {
131 	if (ops->flush_cache)
132 		ops->flush_cache(ops);
133 }
134 
135 static int __fib_rules_register(struct fib_rules_ops *ops)
136 {
137 	int err = -EEXIST;
138 	struct fib_rules_ops *o;
139 	struct net *net;
140 
141 	net = ops->fro_net;
142 
143 	if (ops->rule_size < sizeof(struct fib_rule))
144 		return -EINVAL;
145 
146 	if (ops->match == NULL || ops->configure == NULL ||
147 	    ops->compare == NULL || ops->fill == NULL ||
148 	    ops->action == NULL)
149 		return -EINVAL;
150 
151 	spin_lock(&net->rules_mod_lock);
152 	list_for_each_entry(o, &net->rules_ops, list)
153 		if (ops->family == o->family)
154 			goto errout;
155 
156 	list_add_tail_rcu(&ops->list, &net->rules_ops);
157 	err = 0;
158 errout:
159 	spin_unlock(&net->rules_mod_lock);
160 
161 	return err;
162 }
163 
164 struct fib_rules_ops *
165 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
166 {
167 	struct fib_rules_ops *ops;
168 	int err;
169 
170 	ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
171 	if (ops == NULL)
172 		return ERR_PTR(-ENOMEM);
173 
174 	INIT_LIST_HEAD(&ops->rules_list);
175 	ops->fro_net = net;
176 
177 	err = __fib_rules_register(ops);
178 	if (err) {
179 		kfree(ops);
180 		ops = ERR_PTR(err);
181 	}
182 
183 	return ops;
184 }
185 EXPORT_SYMBOL_GPL(fib_rules_register);
186 
187 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
188 {
189 	struct fib_rule *rule, *tmp;
190 
191 	list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
192 		list_del_rcu(&rule->list);
193 		if (ops->delete)
194 			ops->delete(rule);
195 		fib_rule_put(rule);
196 	}
197 }
198 
199 void fib_rules_unregister(struct fib_rules_ops *ops)
200 {
201 	struct net *net = ops->fro_net;
202 
203 	spin_lock(&net->rules_mod_lock);
204 	list_del_rcu(&ops->list);
205 	spin_unlock(&net->rules_mod_lock);
206 
207 	fib_rules_cleanup_ops(ops);
208 	kfree_rcu(ops, rcu);
209 }
210 EXPORT_SYMBOL_GPL(fib_rules_unregister);
211 
212 static int uid_range_set(struct fib_kuid_range *range)
213 {
214 	return uid_valid(range->start) && uid_valid(range->end);
215 }
216 
217 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
218 {
219 	struct fib_rule_uid_range *in;
220 	struct fib_kuid_range out;
221 
222 	in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
223 
224 	out.start = make_kuid(current_user_ns(), in->start);
225 	out.end = make_kuid(current_user_ns(), in->end);
226 
227 	return out;
228 }
229 
230 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
231 {
232 	struct fib_rule_uid_range out = {
233 		from_kuid_munged(current_user_ns(), range->start),
234 		from_kuid_munged(current_user_ns(), range->end)
235 	};
236 
237 	return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
238 }
239 
240 static int nla_get_port_range(struct nlattr *pattr,
241 			      struct fib_rule_port_range *port_range)
242 {
243 	const struct fib_rule_port_range *pr = nla_data(pattr);
244 
245 	if (!fib_rule_port_range_valid(pr))
246 		return -EINVAL;
247 
248 	port_range->start = pr->start;
249 	port_range->end = pr->end;
250 
251 	return 0;
252 }
253 
254 static int nla_put_port_range(struct sk_buff *skb, int attrtype,
255 			      struct fib_rule_port_range *range)
256 {
257 	return nla_put(skb, attrtype, sizeof(*range), range);
258 }
259 
260 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
261 			  struct flowi *fl, int flags,
262 			  struct fib_lookup_arg *arg)
263 {
264 	int iifindex, oifindex, ret = 0;
265 
266 	iifindex = READ_ONCE(rule->iifindex);
267 	if (iifindex && (iifindex != fl->flowi_iif))
268 		goto out;
269 
270 	oifindex = READ_ONCE(rule->oifindex);
271 	if (oifindex && (oifindex != fl->flowi_oif))
272 		goto out;
273 
274 	if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
275 		goto out;
276 
277 	if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
278 		goto out;
279 
280 	if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
281 		goto out;
282 
283 	if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
284 	    uid_gt(fl->flowi_uid, rule->uid_range.end))
285 		goto out;
286 
287 	ret = INDIRECT_CALL_MT(ops->match,
288 			       fib6_rule_match,
289 			       fib4_rule_match,
290 			       rule, fl, flags);
291 out:
292 	return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
293 }
294 
295 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
296 		     int flags, struct fib_lookup_arg *arg)
297 {
298 	struct fib_rule *rule;
299 	int err;
300 
301 	rcu_read_lock();
302 
303 	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
304 jumped:
305 		if (!fib_rule_match(rule, ops, fl, flags, arg))
306 			continue;
307 
308 		if (rule->action == FR_ACT_GOTO) {
309 			struct fib_rule *target;
310 
311 			target = rcu_dereference(rule->ctarget);
312 			if (target == NULL) {
313 				continue;
314 			} else {
315 				rule = target;
316 				goto jumped;
317 			}
318 		} else if (rule->action == FR_ACT_NOP)
319 			continue;
320 		else
321 			err = INDIRECT_CALL_MT(ops->action,
322 					       fib6_rule_action,
323 					       fib4_rule_action,
324 					       rule, fl, flags, arg);
325 
326 		if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress,
327 							      fib6_rule_suppress,
328 							      fib4_rule_suppress,
329 							      rule, flags, arg))
330 			continue;
331 
332 		if (err != -EAGAIN) {
333 			if ((arg->flags & FIB_LOOKUP_NOREF) ||
334 			    likely(refcount_inc_not_zero(&rule->refcnt))) {
335 				arg->rule = rule;
336 				goto out;
337 			}
338 			break;
339 		}
340 	}
341 
342 	err = -ESRCH;
343 out:
344 	rcu_read_unlock();
345 
346 	return err;
347 }
348 EXPORT_SYMBOL_GPL(fib_rules_lookup);
349 
350 static int call_fib_rule_notifier(struct notifier_block *nb,
351 				  enum fib_event_type event_type,
352 				  struct fib_rule *rule, int family,
353 				  struct netlink_ext_ack *extack)
354 {
355 	struct fib_rule_notifier_info info = {
356 		.info.family = family,
357 		.info.extack = extack,
358 		.rule = rule,
359 	};
360 
361 	return call_fib_notifier(nb, event_type, &info.info);
362 }
363 
364 static int call_fib_rule_notifiers(struct net *net,
365 				   enum fib_event_type event_type,
366 				   struct fib_rule *rule,
367 				   struct fib_rules_ops *ops,
368 				   struct netlink_ext_ack *extack)
369 {
370 	struct fib_rule_notifier_info info = {
371 		.info.family = ops->family,
372 		.info.extack = extack,
373 		.rule = rule,
374 	};
375 
376 	ASSERT_RTNL_NET(net);
377 
378 	/* Paired with READ_ONCE() in fib_rules_seq() */
379 	WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1);
380 	return call_fib_notifiers(net, event_type, &info.info);
381 }
382 
383 /* Called with rcu_read_lock() */
384 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
385 		   struct netlink_ext_ack *extack)
386 {
387 	struct fib_rules_ops *ops;
388 	struct fib_rule *rule;
389 	int err = 0;
390 
391 	ops = lookup_rules_ops(net, family);
392 	if (!ops)
393 		return -EAFNOSUPPORT;
394 	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
395 		err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD,
396 					     rule, family, extack);
397 		if (err)
398 			break;
399 	}
400 	rules_ops_put(ops);
401 
402 	return err;
403 }
404 EXPORT_SYMBOL_GPL(fib_rules_dump);
405 
406 unsigned int fib_rules_seq_read(const struct net *net, int family)
407 {
408 	unsigned int fib_rules_seq;
409 	struct fib_rules_ops *ops;
410 
411 	ops = lookup_rules_ops(net, family);
412 	if (!ops)
413 		return 0;
414 	/* Paired with WRITE_ONCE() in call_fib_rule_notifiers() */
415 	fib_rules_seq = READ_ONCE(ops->fib_rules_seq);
416 	rules_ops_put(ops);
417 
418 	return fib_rules_seq;
419 }
420 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
421 
422 static struct fib_rule *rule_find(struct fib_rules_ops *ops,
423 				  struct fib_rule_hdr *frh,
424 				  struct nlattr **tb,
425 				  struct fib_rule *rule,
426 				  bool user_priority)
427 {
428 	struct fib_rule *r;
429 
430 	list_for_each_entry(r, &ops->rules_list, list) {
431 		if (rule->action && r->action != rule->action)
432 			continue;
433 
434 		if (rule->table && r->table != rule->table)
435 			continue;
436 
437 		if (user_priority && r->pref != rule->pref)
438 			continue;
439 
440 		if (rule->iifname[0] &&
441 		    memcmp(r->iifname, rule->iifname, IFNAMSIZ))
442 			continue;
443 
444 		if (rule->oifname[0] &&
445 		    memcmp(r->oifname, rule->oifname, IFNAMSIZ))
446 			continue;
447 
448 		if (rule->mark && r->mark != rule->mark)
449 			continue;
450 
451 		if (rule->suppress_ifgroup != -1 &&
452 		    r->suppress_ifgroup != rule->suppress_ifgroup)
453 			continue;
454 
455 		if (rule->suppress_prefixlen != -1 &&
456 		    r->suppress_prefixlen != rule->suppress_prefixlen)
457 			continue;
458 
459 		if (rule->mark_mask && r->mark_mask != rule->mark_mask)
460 			continue;
461 
462 		if (rule->tun_id && r->tun_id != rule->tun_id)
463 			continue;
464 
465 		if (rule->l3mdev && r->l3mdev != rule->l3mdev)
466 			continue;
467 
468 		if (uid_range_set(&rule->uid_range) &&
469 		    (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
470 		    !uid_eq(r->uid_range.end, rule->uid_range.end)))
471 			continue;
472 
473 		if (rule->ip_proto && r->ip_proto != rule->ip_proto)
474 			continue;
475 
476 		if (rule->proto && r->proto != rule->proto)
477 			continue;
478 
479 		if (fib_rule_port_range_set(&rule->sport_range) &&
480 		    !fib_rule_port_range_compare(&r->sport_range,
481 						 &rule->sport_range))
482 			continue;
483 
484 		if (fib_rule_port_range_set(&rule->dport_range) &&
485 		    !fib_rule_port_range_compare(&r->dport_range,
486 						 &rule->dport_range))
487 			continue;
488 
489 		if (!ops->compare(r, frh, tb))
490 			continue;
491 		return r;
492 	}
493 
494 	return NULL;
495 }
496 
497 #ifdef CONFIG_NET_L3_MASTER_DEV
498 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
499 			      struct netlink_ext_ack *extack)
500 {
501 	nlrule->l3mdev = nla_get_u8(nla);
502 	if (nlrule->l3mdev != 1) {
503 		NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
504 		return -1;
505 	}
506 
507 	return 0;
508 }
509 #else
510 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
511 			      struct netlink_ext_ack *extack)
512 {
513 	NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
514 	return -1;
515 }
516 #endif
517 
518 static int fib_nl2rule(struct net *net, struct nlmsghdr *nlh,
519 		       struct netlink_ext_ack *extack,
520 		       struct fib_rules_ops *ops,
521 		       struct nlattr *tb[],
522 		       struct fib_rule **rule,
523 		       bool *user_priority)
524 {
525 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
526 	struct fib_rule *nlrule = NULL;
527 	int err = -EINVAL;
528 
529 	if (frh->src_len)
530 		if (!tb[FRA_SRC] ||
531 		    frh->src_len > (ops->addr_size * 8) ||
532 		    nla_len(tb[FRA_SRC]) != ops->addr_size) {
533 			NL_SET_ERR_MSG(extack, "Invalid source address");
534 			goto errout;
535 	}
536 
537 	if (frh->dst_len)
538 		if (!tb[FRA_DST] ||
539 		    frh->dst_len > (ops->addr_size * 8) ||
540 		    nla_len(tb[FRA_DST]) != ops->addr_size) {
541 			NL_SET_ERR_MSG(extack, "Invalid dst address");
542 			goto errout;
543 	}
544 
545 	nlrule = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
546 	if (!nlrule) {
547 		err = -ENOMEM;
548 		goto errout;
549 	}
550 	refcount_set(&nlrule->refcnt, 1);
551 	nlrule->fr_net = net;
552 
553 	if (tb[FRA_PRIORITY]) {
554 		nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
555 		*user_priority = true;
556 	}
557 
558 	nlrule->proto = nla_get_u8_default(tb[FRA_PROTOCOL], RTPROT_UNSPEC);
559 
560 	if (tb[FRA_IIFNAME]) {
561 		nlrule->iifindex = -1;
562 		nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
563 	}
564 
565 	if (tb[FRA_OIFNAME]) {
566 		nlrule->oifindex = -1;
567 		nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
568 	}
569 
570 	if (tb[FRA_FWMARK]) {
571 		nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
572 		if (nlrule->mark)
573 			/* compatibility: if the mark value is non-zero all bits
574 			 * are compared unless a mask is explicitly specified.
575 			 */
576 			nlrule->mark_mask = 0xFFFFFFFF;
577 	}
578 
579 	if (tb[FRA_FWMASK])
580 		nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
581 
582 	if (tb[FRA_TUN_ID])
583 		nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
584 
585 	if (tb[FRA_L3MDEV] &&
586 	    fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
587 		goto errout_free;
588 
589 	nlrule->action = frh->action;
590 	nlrule->flags = frh->flags;
591 	nlrule->table = frh_get_table(frh, tb);
592 	if (tb[FRA_SUPPRESS_PREFIXLEN])
593 		nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
594 	else
595 		nlrule->suppress_prefixlen = -1;
596 
597 	if (tb[FRA_SUPPRESS_IFGROUP])
598 		nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
599 	else
600 		nlrule->suppress_ifgroup = -1;
601 
602 	if (tb[FRA_GOTO]) {
603 		if (nlrule->action != FR_ACT_GOTO) {
604 			NL_SET_ERR_MSG(extack, "Unexpected goto");
605 			goto errout_free;
606 		}
607 
608 		nlrule->target = nla_get_u32(tb[FRA_GOTO]);
609 	} else if (nlrule->action == FR_ACT_GOTO) {
610 		NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
611 		goto errout_free;
612 	}
613 
614 	if (nlrule->l3mdev && nlrule->table) {
615 		NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
616 		goto errout_free;
617 	}
618 
619 	if (tb[FRA_UID_RANGE]) {
620 		if (current_user_ns() != net->user_ns) {
621 			err = -EPERM;
622 			NL_SET_ERR_MSG(extack, "No permission to set uid");
623 			goto errout_free;
624 		}
625 
626 		nlrule->uid_range = nla_get_kuid_range(tb);
627 
628 		if (!uid_range_set(&nlrule->uid_range) ||
629 		    !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
630 			NL_SET_ERR_MSG(extack, "Invalid uid range");
631 			goto errout_free;
632 		}
633 	} else {
634 		nlrule->uid_range = fib_kuid_range_unset;
635 	}
636 
637 	if (tb[FRA_IP_PROTO])
638 		nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
639 
640 	if (tb[FRA_SPORT_RANGE]) {
641 		err = nla_get_port_range(tb[FRA_SPORT_RANGE],
642 					 &nlrule->sport_range);
643 		if (err) {
644 			NL_SET_ERR_MSG(extack, "Invalid sport range");
645 			goto errout_free;
646 		}
647 	}
648 
649 	if (tb[FRA_DPORT_RANGE]) {
650 		err = nla_get_port_range(tb[FRA_DPORT_RANGE],
651 					 &nlrule->dport_range);
652 		if (err) {
653 			NL_SET_ERR_MSG(extack, "Invalid dport range");
654 			goto errout_free;
655 		}
656 	}
657 
658 	*rule = nlrule;
659 
660 	return 0;
661 
662 errout_free:
663 	kfree(nlrule);
664 errout:
665 	return err;
666 }
667 
668 static int fib_nl2rule_rtnl(struct fib_rule *nlrule,
669 			    struct fib_rules_ops *ops,
670 			    struct nlattr *tb[],
671 			    struct netlink_ext_ack *extack)
672 {
673 	if (!tb[FRA_PRIORITY])
674 		nlrule->pref = fib_default_rule_pref(ops);
675 
676 	/* Backward jumps are prohibited to avoid endless loops */
677 	if (tb[FRA_GOTO] && nlrule->target <= nlrule->pref) {
678 		NL_SET_ERR_MSG(extack, "Backward goto not supported");
679 		return -EINVAL;
680 	}
681 
682 	if (tb[FRA_IIFNAME]) {
683 		struct net_device *dev;
684 
685 		dev = __dev_get_by_name(nlrule->fr_net, nlrule->iifname);
686 		if (dev)
687 			nlrule->iifindex = dev->ifindex;
688 	}
689 
690 	if (tb[FRA_OIFNAME]) {
691 		struct net_device *dev;
692 
693 		dev = __dev_get_by_name(nlrule->fr_net, nlrule->oifname);
694 		if (dev)
695 			nlrule->oifindex = dev->ifindex;
696 	}
697 
698 	return 0;
699 }
700 
701 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
702 		       struct nlattr **tb, struct fib_rule *rule)
703 {
704 	struct fib_rule *r;
705 
706 	list_for_each_entry(r, &ops->rules_list, list) {
707 		if (r->action != rule->action)
708 			continue;
709 
710 		if (r->table != rule->table)
711 			continue;
712 
713 		if (r->pref != rule->pref)
714 			continue;
715 
716 		if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
717 			continue;
718 
719 		if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
720 			continue;
721 
722 		if (r->mark != rule->mark)
723 			continue;
724 
725 		if (r->suppress_ifgroup != rule->suppress_ifgroup)
726 			continue;
727 
728 		if (r->suppress_prefixlen != rule->suppress_prefixlen)
729 			continue;
730 
731 		if (r->mark_mask != rule->mark_mask)
732 			continue;
733 
734 		if (r->tun_id != rule->tun_id)
735 			continue;
736 
737 		if (r->l3mdev != rule->l3mdev)
738 			continue;
739 
740 		if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
741 		    !uid_eq(r->uid_range.end, rule->uid_range.end))
742 			continue;
743 
744 		if (r->ip_proto != rule->ip_proto)
745 			continue;
746 
747 		if (r->proto != rule->proto)
748 			continue;
749 
750 		if (!fib_rule_port_range_compare(&r->sport_range,
751 						 &rule->sport_range))
752 			continue;
753 
754 		if (!fib_rule_port_range_compare(&r->dport_range,
755 						 &rule->dport_range))
756 			continue;
757 
758 		if (!ops->compare(r, frh, tb))
759 			continue;
760 		return 1;
761 	}
762 	return 0;
763 }
764 
765 static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = {
766 	[FRA_UNSPEC]	= { .strict_start_type = FRA_DPORT_RANGE + 1 },
767 	[FRA_IIFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
768 	[FRA_OIFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
769 	[FRA_PRIORITY]	= { .type = NLA_U32 },
770 	[FRA_FWMARK]	= { .type = NLA_U32 },
771 	[FRA_FLOW]	= { .type = NLA_U32 },
772 	[FRA_TUN_ID]	= { .type = NLA_U64 },
773 	[FRA_FWMASK]	= { .type = NLA_U32 },
774 	[FRA_TABLE]     = { .type = NLA_U32 },
775 	[FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 },
776 	[FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 },
777 	[FRA_GOTO]	= { .type = NLA_U32 },
778 	[FRA_L3MDEV]	= { .type = NLA_U8 },
779 	[FRA_UID_RANGE]	= { .len = sizeof(struct fib_rule_uid_range) },
780 	[FRA_PROTOCOL]  = { .type = NLA_U8 },
781 	[FRA_IP_PROTO]  = { .type = NLA_U8 },
782 	[FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
783 	[FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
784 	[FRA_DSCP]	= NLA_POLICY_MAX(NLA_U8, INET_DSCP_MASK >> 2),
785 	[FRA_FLOWLABEL] = { .type = NLA_BE32 },
786 	[FRA_FLOWLABEL_MASK] = { .type = NLA_BE32 },
787 };
788 
789 int fib_newrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
790 		struct netlink_ext_ack *extack, bool rtnl_held)
791 {
792 	struct fib_rule *rule = NULL, *r, *last = NULL;
793 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
794 	int err = -EINVAL, unresolved = 0;
795 	struct fib_rules_ops *ops = NULL;
796 	struct nlattr *tb[FRA_MAX + 1];
797 	bool user_priority = false;
798 
799 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
800 		NL_SET_ERR_MSG(extack, "Invalid msg length");
801 		goto errout;
802 	}
803 
804 	ops = lookup_rules_ops(net, frh->family);
805 	if (!ops) {
806 		err = -EAFNOSUPPORT;
807 		NL_SET_ERR_MSG(extack, "Rule family not supported");
808 		goto errout;
809 	}
810 
811 	err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
812 				     fib_rule_policy, extack);
813 	if (err < 0) {
814 		NL_SET_ERR_MSG(extack, "Error parsing msg");
815 		goto errout;
816 	}
817 
818 	err = fib_nl2rule(net, nlh, extack, ops, tb, &rule, &user_priority);
819 	if (err)
820 		goto errout;
821 
822 	if (!rtnl_held)
823 		rtnl_net_lock(net);
824 
825 	err = fib_nl2rule_rtnl(rule, ops, tb, extack);
826 	if (err)
827 		goto errout_free;
828 
829 	if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
830 	    rule_exists(ops, frh, tb, rule)) {
831 		err = -EEXIST;
832 		goto errout_free;
833 	}
834 
835 	err = ops->configure(rule, skb, frh, tb, extack);
836 	if (err < 0)
837 		goto errout_free;
838 
839 	err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
840 				      extack);
841 	if (err < 0)
842 		goto errout_free;
843 
844 	list_for_each_entry(r, &ops->rules_list, list) {
845 		if (r->pref == rule->target) {
846 			RCU_INIT_POINTER(rule->ctarget, r);
847 			break;
848 		}
849 	}
850 
851 	if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
852 		unresolved = 1;
853 
854 	list_for_each_entry(r, &ops->rules_list, list) {
855 		if (r->pref > rule->pref)
856 			break;
857 		last = r;
858 	}
859 
860 	if (last)
861 		list_add_rcu(&rule->list, &last->list);
862 	else
863 		list_add_rcu(&rule->list, &ops->rules_list);
864 
865 	if (ops->unresolved_rules) {
866 		/*
867 		 * There are unresolved goto rules in the list, check if
868 		 * any of them are pointing to this new rule.
869 		 */
870 		list_for_each_entry(r, &ops->rules_list, list) {
871 			if (r->action == FR_ACT_GOTO &&
872 			    r->target == rule->pref &&
873 			    rtnl_dereference(r->ctarget) == NULL) {
874 				rcu_assign_pointer(r->ctarget, rule);
875 				if (--ops->unresolved_rules == 0)
876 					break;
877 			}
878 		}
879 	}
880 
881 	if (rule->action == FR_ACT_GOTO)
882 		ops->nr_goto_rules++;
883 
884 	if (unresolved)
885 		ops->unresolved_rules++;
886 
887 	if (rule->tun_id)
888 		ip_tunnel_need_metadata();
889 
890 	fib_rule_get(rule);
891 
892 	if (!rtnl_held)
893 		rtnl_net_unlock(net);
894 
895 	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
896 	fib_rule_put(rule);
897 	flush_route_cache(ops);
898 	rules_ops_put(ops);
899 	return 0;
900 
901 errout_free:
902 	if (!rtnl_held)
903 		rtnl_net_unlock(net);
904 	kfree(rule);
905 errout:
906 	rules_ops_put(ops);
907 	return err;
908 }
909 EXPORT_SYMBOL_GPL(fib_newrule);
910 
911 static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
912 			  struct netlink_ext_ack *extack)
913 {
914 	return fib_newrule(sock_net(skb->sk), skb, nlh, extack, false);
915 }
916 
917 int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
918 		struct netlink_ext_ack *extack, bool rtnl_held)
919 {
920 	struct fib_rule *rule = NULL, *nlrule = NULL;
921 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
922 	struct fib_rules_ops *ops = NULL;
923 	struct nlattr *tb[FRA_MAX+1];
924 	bool user_priority = false;
925 	int err = -EINVAL;
926 
927 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
928 		NL_SET_ERR_MSG(extack, "Invalid msg length");
929 		goto errout;
930 	}
931 
932 	ops = lookup_rules_ops(net, frh->family);
933 	if (ops == NULL) {
934 		err = -EAFNOSUPPORT;
935 		NL_SET_ERR_MSG(extack, "Rule family not supported");
936 		goto errout;
937 	}
938 
939 	err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
940 				     fib_rule_policy, extack);
941 	if (err < 0) {
942 		NL_SET_ERR_MSG(extack, "Error parsing msg");
943 		goto errout;
944 	}
945 
946 	err = fib_nl2rule(net, nlh, extack, ops, tb, &nlrule, &user_priority);
947 	if (err)
948 		goto errout;
949 
950 	if (!rtnl_held)
951 		rtnl_net_lock(net);
952 
953 	err = fib_nl2rule_rtnl(nlrule, ops, tb, extack);
954 	if (err)
955 		goto errout_free;
956 
957 	rule = rule_find(ops, frh, tb, nlrule, user_priority);
958 	if (!rule) {
959 		err = -ENOENT;
960 		goto errout_free;
961 	}
962 
963 	if (rule->flags & FIB_RULE_PERMANENT) {
964 		err = -EPERM;
965 		goto errout_free;
966 	}
967 
968 	if (ops->delete) {
969 		err = ops->delete(rule);
970 		if (err)
971 			goto errout_free;
972 	}
973 
974 	if (rule->tun_id)
975 		ip_tunnel_unneed_metadata();
976 
977 	list_del_rcu(&rule->list);
978 
979 	if (rule->action == FR_ACT_GOTO) {
980 		ops->nr_goto_rules--;
981 		if (rtnl_dereference(rule->ctarget) == NULL)
982 			ops->unresolved_rules--;
983 	}
984 
985 	/*
986 	 * Check if this rule is a target to any of them. If so,
987 	 * adjust to the next one with the same preference or
988 	 * disable them. As this operation is eventually very
989 	 * expensive, it is only performed if goto rules, except
990 	 * current if it is goto rule, have actually been added.
991 	 */
992 	if (ops->nr_goto_rules > 0) {
993 		struct fib_rule *n, *r;
994 
995 		n = list_next_entry(rule, list);
996 		if (&n->list == &ops->rules_list || n->pref != rule->pref)
997 			n = NULL;
998 		list_for_each_entry(r, &ops->rules_list, list) {
999 			if (rtnl_dereference(r->ctarget) != rule)
1000 				continue;
1001 			rcu_assign_pointer(r->ctarget, n);
1002 			if (!n)
1003 				ops->unresolved_rules++;
1004 		}
1005 	}
1006 
1007 	call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, NULL);
1008 
1009 	if (!rtnl_held)
1010 		rtnl_net_unlock(net);
1011 
1012 	notify_rule_change(RTM_DELRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
1013 	fib_rule_put(rule);
1014 	flush_route_cache(ops);
1015 	rules_ops_put(ops);
1016 	kfree(nlrule);
1017 	return 0;
1018 
1019 errout_free:
1020 	if (!rtnl_held)
1021 		rtnl_net_unlock(net);
1022 	kfree(nlrule);
1023 errout:
1024 	rules_ops_put(ops);
1025 	return err;
1026 }
1027 EXPORT_SYMBOL_GPL(fib_delrule);
1028 
1029 static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
1030 			  struct netlink_ext_ack *extack)
1031 {
1032 	return fib_delrule(sock_net(skb->sk), skb, nlh, extack, false);
1033 }
1034 
1035 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
1036 					 struct fib_rule *rule)
1037 {
1038 	size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
1039 			 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
1040 			 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
1041 			 + nla_total_size(4) /* FRA_PRIORITY */
1042 			 + nla_total_size(4) /* FRA_TABLE */
1043 			 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
1044 			 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
1045 			 + nla_total_size(4) /* FRA_FWMARK */
1046 			 + nla_total_size(4) /* FRA_FWMASK */
1047 			 + nla_total_size_64bit(8) /* FRA_TUN_ID */
1048 			 + nla_total_size(sizeof(struct fib_kuid_range))
1049 			 + nla_total_size(1) /* FRA_PROTOCOL */
1050 			 + nla_total_size(1) /* FRA_IP_PROTO */
1051 			 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
1052 			 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
1053 
1054 	if (ops->nlmsg_payload)
1055 		payload += ops->nlmsg_payload(rule);
1056 
1057 	return payload;
1058 }
1059 
1060 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
1061 			    u32 pid, u32 seq, int type, int flags,
1062 			    struct fib_rules_ops *ops)
1063 {
1064 	struct nlmsghdr *nlh;
1065 	struct fib_rule_hdr *frh;
1066 
1067 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
1068 	if (nlh == NULL)
1069 		return -EMSGSIZE;
1070 
1071 	frh = nlmsg_data(nlh);
1072 	frh->family = ops->family;
1073 	frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT;
1074 	if (nla_put_u32(skb, FRA_TABLE, rule->table))
1075 		goto nla_put_failure;
1076 	if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
1077 		goto nla_put_failure;
1078 	frh->res1 = 0;
1079 	frh->res2 = 0;
1080 	frh->action = rule->action;
1081 	frh->flags = rule->flags;
1082 
1083 	if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
1084 		goto nla_put_failure;
1085 
1086 	if (rule->action == FR_ACT_GOTO &&
1087 	    rcu_access_pointer(rule->ctarget) == NULL)
1088 		frh->flags |= FIB_RULE_UNRESOLVED;
1089 
1090 	if (rule->iifname[0]) {
1091 		if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
1092 			goto nla_put_failure;
1093 		if (READ_ONCE(rule->iifindex) == -1)
1094 			frh->flags |= FIB_RULE_IIF_DETACHED;
1095 	}
1096 
1097 	if (rule->oifname[0]) {
1098 		if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
1099 			goto nla_put_failure;
1100 		if (READ_ONCE(rule->oifindex) == -1)
1101 			frh->flags |= FIB_RULE_OIF_DETACHED;
1102 	}
1103 
1104 	if ((rule->pref &&
1105 	     nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
1106 	    (rule->mark &&
1107 	     nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
1108 	    ((rule->mark_mask || rule->mark) &&
1109 	     nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
1110 	    (rule->target &&
1111 	     nla_put_u32(skb, FRA_GOTO, rule->target)) ||
1112 	    (rule->tun_id &&
1113 	     nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
1114 	    (rule->l3mdev &&
1115 	     nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
1116 	    (uid_range_set(&rule->uid_range) &&
1117 	     nla_put_uid_range(skb, &rule->uid_range)) ||
1118 	    (fib_rule_port_range_set(&rule->sport_range) &&
1119 	     nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
1120 	    (fib_rule_port_range_set(&rule->dport_range) &&
1121 	     nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
1122 	    (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
1123 		goto nla_put_failure;
1124 
1125 	if (rule->suppress_ifgroup != -1) {
1126 		if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
1127 			goto nla_put_failure;
1128 	}
1129 
1130 	if (ops->fill(rule, skb, frh) < 0)
1131 		goto nla_put_failure;
1132 
1133 	nlmsg_end(skb, nlh);
1134 	return 0;
1135 
1136 nla_put_failure:
1137 	nlmsg_cancel(skb, nlh);
1138 	return -EMSGSIZE;
1139 }
1140 
1141 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
1142 		      struct fib_rules_ops *ops)
1143 {
1144 	int idx = 0;
1145 	struct fib_rule *rule;
1146 	int err = 0;
1147 
1148 	rcu_read_lock();
1149 	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
1150 		if (idx < cb->args[1])
1151 			goto skip;
1152 
1153 		err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
1154 				       cb->nlh->nlmsg_seq, RTM_NEWRULE,
1155 				       NLM_F_MULTI, ops);
1156 		if (err)
1157 			break;
1158 skip:
1159 		idx++;
1160 	}
1161 	rcu_read_unlock();
1162 	cb->args[1] = idx;
1163 	rules_ops_put(ops);
1164 
1165 	return err;
1166 }
1167 
1168 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
1169 				   struct netlink_ext_ack *extack)
1170 {
1171 	struct fib_rule_hdr *frh;
1172 
1173 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1174 		NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
1175 		return -EINVAL;
1176 	}
1177 
1178 	frh = nlmsg_data(nlh);
1179 	if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
1180 	    frh->res1 || frh->res2 || frh->action || frh->flags) {
1181 		NL_SET_ERR_MSG(extack,
1182 			       "Invalid values in header for fib rule dump request");
1183 		return -EINVAL;
1184 	}
1185 
1186 	if (nlmsg_attrlen(nlh, sizeof(*frh))) {
1187 		NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
1188 		return -EINVAL;
1189 	}
1190 
1191 	return 0;
1192 }
1193 
1194 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
1195 {
1196 	const struct nlmsghdr *nlh = cb->nlh;
1197 	struct net *net = sock_net(skb->sk);
1198 	struct fib_rules_ops *ops;
1199 	int err, idx = 0, family;
1200 
1201 	if (cb->strict_check) {
1202 		err = fib_valid_dumprule_req(nlh, cb->extack);
1203 
1204 		if (err < 0)
1205 			return err;
1206 	}
1207 
1208 	family = rtnl_msg_family(nlh);
1209 	if (family != AF_UNSPEC) {
1210 		/* Protocol specific dump request */
1211 		ops = lookup_rules_ops(net, family);
1212 		if (ops == NULL)
1213 			return -EAFNOSUPPORT;
1214 
1215 		return dump_rules(skb, cb, ops);
1216 	}
1217 
1218 	err = 0;
1219 	rcu_read_lock();
1220 	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1221 		if (idx < cb->args[0] || !try_module_get(ops->owner))
1222 			goto skip;
1223 
1224 		err = dump_rules(skb, cb, ops);
1225 		if (err < 0)
1226 			break;
1227 
1228 		cb->args[1] = 0;
1229 skip:
1230 		idx++;
1231 	}
1232 	rcu_read_unlock();
1233 	cb->args[0] = idx;
1234 
1235 	return err;
1236 }
1237 
1238 static void notify_rule_change(int event, struct fib_rule *rule,
1239 			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1240 			       u32 pid)
1241 {
1242 	struct net *net;
1243 	struct sk_buff *skb;
1244 	int err = -ENOMEM;
1245 
1246 	net = ops->fro_net;
1247 	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1248 	if (skb == NULL)
1249 		goto errout;
1250 
1251 	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1252 	if (err < 0) {
1253 		/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1254 		WARN_ON(err == -EMSGSIZE);
1255 		kfree_skb(skb);
1256 		goto errout;
1257 	}
1258 
1259 	rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1260 	return;
1261 errout:
1262 	rtnl_set_sk_err(net, ops->nlgroup, err);
1263 }
1264 
1265 static void attach_rules(struct list_head *rules, struct net_device *dev)
1266 {
1267 	struct fib_rule *rule;
1268 
1269 	list_for_each_entry(rule, rules, list) {
1270 		if (rule->iifindex == -1 &&
1271 		    strcmp(dev->name, rule->iifname) == 0)
1272 			WRITE_ONCE(rule->iifindex, dev->ifindex);
1273 		if (rule->oifindex == -1 &&
1274 		    strcmp(dev->name, rule->oifname) == 0)
1275 			WRITE_ONCE(rule->oifindex, dev->ifindex);
1276 	}
1277 }
1278 
1279 static void detach_rules(struct list_head *rules, struct net_device *dev)
1280 {
1281 	struct fib_rule *rule;
1282 
1283 	list_for_each_entry(rule, rules, list) {
1284 		if (rule->iifindex == dev->ifindex)
1285 			WRITE_ONCE(rule->iifindex, -1);
1286 		if (rule->oifindex == dev->ifindex)
1287 			WRITE_ONCE(rule->oifindex, -1);
1288 	}
1289 }
1290 
1291 
1292 static int fib_rules_event(struct notifier_block *this, unsigned long event,
1293 			   void *ptr)
1294 {
1295 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1296 	struct net *net = dev_net(dev);
1297 	struct fib_rules_ops *ops;
1298 
1299 	ASSERT_RTNL();
1300 
1301 	switch (event) {
1302 	case NETDEV_REGISTER:
1303 		list_for_each_entry(ops, &net->rules_ops, list)
1304 			attach_rules(&ops->rules_list, dev);
1305 		break;
1306 
1307 	case NETDEV_CHANGENAME:
1308 		list_for_each_entry(ops, &net->rules_ops, list) {
1309 			detach_rules(&ops->rules_list, dev);
1310 			attach_rules(&ops->rules_list, dev);
1311 		}
1312 		break;
1313 
1314 	case NETDEV_UNREGISTER:
1315 		list_for_each_entry(ops, &net->rules_ops, list)
1316 			detach_rules(&ops->rules_list, dev);
1317 		break;
1318 	}
1319 
1320 	return NOTIFY_DONE;
1321 }
1322 
1323 static struct notifier_block fib_rules_notifier = {
1324 	.notifier_call = fib_rules_event,
1325 };
1326 
1327 static int __net_init fib_rules_net_init(struct net *net)
1328 {
1329 	INIT_LIST_HEAD(&net->rules_ops);
1330 	spin_lock_init(&net->rules_mod_lock);
1331 	return 0;
1332 }
1333 
1334 static void __net_exit fib_rules_net_exit(struct net *net)
1335 {
1336 	WARN_ON_ONCE(!list_empty(&net->rules_ops));
1337 }
1338 
1339 static struct pernet_operations fib_rules_net_ops = {
1340 	.init = fib_rules_net_init,
1341 	.exit = fib_rules_net_exit,
1342 };
1343 
1344 static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = {
1345 	{.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule,
1346 	 .flags = RTNL_FLAG_DOIT_PERNET},
1347 	{.msgtype = RTM_DELRULE, .doit = fib_nl_delrule,
1348 	 .flags = RTNL_FLAG_DOIT_PERNET},
1349 	{.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule,
1350 	 .flags = RTNL_FLAG_DUMP_UNLOCKED},
1351 };
1352 
1353 static int __init fib_rules_init(void)
1354 {
1355 	int err;
1356 
1357 	rtnl_register_many(fib_rules_rtnl_msg_handlers);
1358 
1359 	err = register_pernet_subsys(&fib_rules_net_ops);
1360 	if (err < 0)
1361 		goto fail;
1362 
1363 	err = register_netdevice_notifier(&fib_rules_notifier);
1364 	if (err < 0)
1365 		goto fail_unregister;
1366 
1367 	return 0;
1368 
1369 fail_unregister:
1370 	unregister_pernet_subsys(&fib_rules_net_ops);
1371 fail:
1372 	rtnl_unregister_many(fib_rules_rtnl_msg_handlers);
1373 	return err;
1374 }
1375 
1376 subsys_initcall(fib_rules_init);
1377