xref: /openbmc/linux/net/core/fib_rules.c (revision 66495f30)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * net/core/fib_rules.c		Generic Routing Rules
4  *
5  * Authors:	Thomas Graf <tgraf@suug.ch>
6  */
7 
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/list.h>
12 #include <linux/module.h>
13 #include <net/net_namespace.h>
14 #include <net/sock.h>
15 #include <net/fib_rules.h>
16 #include <net/ip_tunnels.h>
17 #include <linux/indirect_call_wrapper.h>
18 
19 #if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES)
20 #ifdef CONFIG_IP_MULTIPLE_TABLES
21 #define INDIRECT_CALL_MT(f, f2, f1, ...) \
22 	INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__)
23 #else
24 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
25 #endif
26 #elif defined(CONFIG_IP_MULTIPLE_TABLES)
27 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
28 #else
29 #define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__)
30 #endif
31 
32 static const struct fib_kuid_range fib_kuid_range_unset = {
33 	KUIDT_INIT(0),
34 	KUIDT_INIT(~0),
35 };
36 
fib_rule_matchall(const struct fib_rule * rule)37 bool fib_rule_matchall(const struct fib_rule *rule)
38 {
39 	if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
40 	    rule->flags)
41 		return false;
42 	if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
43 		return false;
44 	if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
45 	    !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
46 		return false;
47 	if (fib_rule_port_range_set(&rule->sport_range))
48 		return false;
49 	if (fib_rule_port_range_set(&rule->dport_range))
50 		return false;
51 	return true;
52 }
53 EXPORT_SYMBOL_GPL(fib_rule_matchall);
54 
fib_default_rule_add(struct fib_rules_ops * ops,u32 pref,u32 table,u32 flags)55 int fib_default_rule_add(struct fib_rules_ops *ops,
56 			 u32 pref, u32 table, u32 flags)
57 {
58 	struct fib_rule *r;
59 
60 	r = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
61 	if (r == NULL)
62 		return -ENOMEM;
63 
64 	refcount_set(&r->refcnt, 1);
65 	r->action = FR_ACT_TO_TBL;
66 	r->pref = pref;
67 	r->table = table;
68 	r->flags = flags;
69 	r->proto = RTPROT_KERNEL;
70 	r->fr_net = ops->fro_net;
71 	r->uid_range = fib_kuid_range_unset;
72 
73 	r->suppress_prefixlen = -1;
74 	r->suppress_ifgroup = -1;
75 
76 	/* The lock is not required here, the list in unreacheable
77 	 * at the moment this function is called */
78 	list_add_tail(&r->list, &ops->rules_list);
79 	return 0;
80 }
81 EXPORT_SYMBOL(fib_default_rule_add);
82 
fib_default_rule_pref(struct fib_rules_ops * ops)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 
lookup_rules_ops(struct net * net,int family)104 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
105 {
106 	struct fib_rules_ops *ops;
107 
108 	rcu_read_lock();
109 	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
110 		if (ops->family == family) {
111 			if (!try_module_get(ops->owner))
112 				ops = NULL;
113 			rcu_read_unlock();
114 			return ops;
115 		}
116 	}
117 	rcu_read_unlock();
118 
119 	return NULL;
120 }
121 
rules_ops_put(struct fib_rules_ops * ops)122 static void rules_ops_put(struct fib_rules_ops *ops)
123 {
124 	if (ops)
125 		module_put(ops->owner);
126 }
127 
flush_route_cache(struct fib_rules_ops * ops)128 static void flush_route_cache(struct fib_rules_ops *ops)
129 {
130 	if (ops->flush_cache)
131 		ops->flush_cache(ops);
132 }
133 
__fib_rules_register(struct fib_rules_ops * ops)134 static int __fib_rules_register(struct fib_rules_ops *ops)
135 {
136 	int err = -EEXIST;
137 	struct fib_rules_ops *o;
138 	struct net *net;
139 
140 	net = ops->fro_net;
141 
142 	if (ops->rule_size < sizeof(struct fib_rule))
143 		return -EINVAL;
144 
145 	if (ops->match == NULL || ops->configure == NULL ||
146 	    ops->compare == NULL || ops->fill == NULL ||
147 	    ops->action == NULL)
148 		return -EINVAL;
149 
150 	spin_lock(&net->rules_mod_lock);
151 	list_for_each_entry(o, &net->rules_ops, list)
152 		if (ops->family == o->family)
153 			goto errout;
154 
155 	list_add_tail_rcu(&ops->list, &net->rules_ops);
156 	err = 0;
157 errout:
158 	spin_unlock(&net->rules_mod_lock);
159 
160 	return err;
161 }
162 
163 struct fib_rules_ops *
fib_rules_register(const struct fib_rules_ops * tmpl,struct net * net)164 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
165 {
166 	struct fib_rules_ops *ops;
167 	int err;
168 
169 	ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
170 	if (ops == NULL)
171 		return ERR_PTR(-ENOMEM);
172 
173 	INIT_LIST_HEAD(&ops->rules_list);
174 	ops->fro_net = net;
175 
176 	err = __fib_rules_register(ops);
177 	if (err) {
178 		kfree(ops);
179 		ops = ERR_PTR(err);
180 	}
181 
182 	return ops;
183 }
184 EXPORT_SYMBOL_GPL(fib_rules_register);
185 
fib_rules_cleanup_ops(struct fib_rules_ops * ops)186 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
187 {
188 	struct fib_rule *rule, *tmp;
189 
190 	list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
191 		list_del_rcu(&rule->list);
192 		if (ops->delete)
193 			ops->delete(rule);
194 		fib_rule_put(rule);
195 	}
196 }
197 
fib_rules_unregister(struct fib_rules_ops * ops)198 void fib_rules_unregister(struct fib_rules_ops *ops)
199 {
200 	struct net *net = ops->fro_net;
201 
202 	spin_lock(&net->rules_mod_lock);
203 	list_del_rcu(&ops->list);
204 	spin_unlock(&net->rules_mod_lock);
205 
206 	fib_rules_cleanup_ops(ops);
207 	kfree_rcu(ops, rcu);
208 }
209 EXPORT_SYMBOL_GPL(fib_rules_unregister);
210 
uid_range_set(struct fib_kuid_range * range)211 static int uid_range_set(struct fib_kuid_range *range)
212 {
213 	return uid_valid(range->start) && uid_valid(range->end);
214 }
215 
nla_get_kuid_range(struct nlattr ** tb)216 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
217 {
218 	struct fib_rule_uid_range *in;
219 	struct fib_kuid_range out;
220 
221 	in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
222 
223 	out.start = make_kuid(current_user_ns(), in->start);
224 	out.end = make_kuid(current_user_ns(), in->end);
225 
226 	return out;
227 }
228 
nla_put_uid_range(struct sk_buff * skb,struct fib_kuid_range * range)229 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
230 {
231 	struct fib_rule_uid_range out = {
232 		from_kuid_munged(current_user_ns(), range->start),
233 		from_kuid_munged(current_user_ns(), range->end)
234 	};
235 
236 	return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
237 }
238 
nla_get_port_range(struct nlattr * pattr,struct fib_rule_port_range * port_range)239 static int nla_get_port_range(struct nlattr *pattr,
240 			      struct fib_rule_port_range *port_range)
241 {
242 	const struct fib_rule_port_range *pr = nla_data(pattr);
243 
244 	if (!fib_rule_port_range_valid(pr))
245 		return -EINVAL;
246 
247 	port_range->start = pr->start;
248 	port_range->end = pr->end;
249 
250 	return 0;
251 }
252 
nla_put_port_range(struct sk_buff * skb,int attrtype,struct fib_rule_port_range * range)253 static int nla_put_port_range(struct sk_buff *skb, int attrtype,
254 			      struct fib_rule_port_range *range)
255 {
256 	return nla_put(skb, attrtype, sizeof(*range), range);
257 }
258 
fib_rule_match(struct fib_rule * rule,struct fib_rules_ops * ops,struct flowi * fl,int flags,struct fib_lookup_arg * arg)259 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
260 			  struct flowi *fl, int flags,
261 			  struct fib_lookup_arg *arg)
262 {
263 	int ret = 0;
264 
265 	if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
266 		goto out;
267 
268 	if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
269 		goto out;
270 
271 	if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
272 		goto out;
273 
274 	if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
275 		goto out;
276 
277 	if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
278 		goto out;
279 
280 	if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
281 	    uid_gt(fl->flowi_uid, rule->uid_range.end))
282 		goto out;
283 
284 	ret = INDIRECT_CALL_MT(ops->match,
285 			       fib6_rule_match,
286 			       fib4_rule_match,
287 			       rule, fl, flags);
288 out:
289 	return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
290 }
291 
fib_rules_lookup(struct fib_rules_ops * ops,struct flowi * fl,int flags,struct fib_lookup_arg * arg)292 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
293 		     int flags, struct fib_lookup_arg *arg)
294 {
295 	struct fib_rule *rule;
296 	int err;
297 
298 	rcu_read_lock();
299 
300 	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
301 jumped:
302 		if (!fib_rule_match(rule, ops, fl, flags, arg))
303 			continue;
304 
305 		if (rule->action == FR_ACT_GOTO) {
306 			struct fib_rule *target;
307 
308 			target = rcu_dereference(rule->ctarget);
309 			if (target == NULL) {
310 				continue;
311 			} else {
312 				rule = target;
313 				goto jumped;
314 			}
315 		} else if (rule->action == FR_ACT_NOP)
316 			continue;
317 		else
318 			err = INDIRECT_CALL_MT(ops->action,
319 					       fib6_rule_action,
320 					       fib4_rule_action,
321 					       rule, fl, flags, arg);
322 
323 		if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress,
324 							      fib6_rule_suppress,
325 							      fib4_rule_suppress,
326 							      rule, flags, arg))
327 			continue;
328 
329 		if (err != -EAGAIN) {
330 			if ((arg->flags & FIB_LOOKUP_NOREF) ||
331 			    likely(refcount_inc_not_zero(&rule->refcnt))) {
332 				arg->rule = rule;
333 				goto out;
334 			}
335 			break;
336 		}
337 	}
338 
339 	err = -ESRCH;
340 out:
341 	rcu_read_unlock();
342 
343 	return err;
344 }
345 EXPORT_SYMBOL_GPL(fib_rules_lookup);
346 
call_fib_rule_notifier(struct notifier_block * nb,enum fib_event_type event_type,struct fib_rule * rule,int family,struct netlink_ext_ack * extack)347 static int call_fib_rule_notifier(struct notifier_block *nb,
348 				  enum fib_event_type event_type,
349 				  struct fib_rule *rule, int family,
350 				  struct netlink_ext_ack *extack)
351 {
352 	struct fib_rule_notifier_info info = {
353 		.info.family = family,
354 		.info.extack = extack,
355 		.rule = rule,
356 	};
357 
358 	return call_fib_notifier(nb, event_type, &info.info);
359 }
360 
call_fib_rule_notifiers(struct net * net,enum fib_event_type event_type,struct fib_rule * rule,struct fib_rules_ops * ops,struct netlink_ext_ack * extack)361 static int call_fib_rule_notifiers(struct net *net,
362 				   enum fib_event_type event_type,
363 				   struct fib_rule *rule,
364 				   struct fib_rules_ops *ops,
365 				   struct netlink_ext_ack *extack)
366 {
367 	struct fib_rule_notifier_info info = {
368 		.info.family = ops->family,
369 		.info.extack = extack,
370 		.rule = rule,
371 	};
372 
373 	ops->fib_rules_seq++;
374 	return call_fib_notifiers(net, event_type, &info.info);
375 }
376 
377 /* Called with rcu_read_lock() */
fib_rules_dump(struct net * net,struct notifier_block * nb,int family,struct netlink_ext_ack * extack)378 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
379 		   struct netlink_ext_ack *extack)
380 {
381 	struct fib_rules_ops *ops;
382 	struct fib_rule *rule;
383 	int err = 0;
384 
385 	ops = lookup_rules_ops(net, family);
386 	if (!ops)
387 		return -EAFNOSUPPORT;
388 	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
389 		err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD,
390 					     rule, family, extack);
391 		if (err)
392 			break;
393 	}
394 	rules_ops_put(ops);
395 
396 	return err;
397 }
398 EXPORT_SYMBOL_GPL(fib_rules_dump);
399 
fib_rules_seq_read(struct net * net,int family)400 unsigned int fib_rules_seq_read(struct net *net, int family)
401 {
402 	unsigned int fib_rules_seq;
403 	struct fib_rules_ops *ops;
404 
405 	ASSERT_RTNL();
406 
407 	ops = lookup_rules_ops(net, family);
408 	if (!ops)
409 		return 0;
410 	fib_rules_seq = ops->fib_rules_seq;
411 	rules_ops_put(ops);
412 
413 	return fib_rules_seq;
414 }
415 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
416 
rule_find(struct fib_rules_ops * ops,struct fib_rule_hdr * frh,struct nlattr ** tb,struct fib_rule * rule,bool user_priority)417 static struct fib_rule *rule_find(struct fib_rules_ops *ops,
418 				  struct fib_rule_hdr *frh,
419 				  struct nlattr **tb,
420 				  struct fib_rule *rule,
421 				  bool user_priority)
422 {
423 	struct fib_rule *r;
424 
425 	list_for_each_entry(r, &ops->rules_list, list) {
426 		if (rule->action && r->action != rule->action)
427 			continue;
428 
429 		if (rule->table && r->table != rule->table)
430 			continue;
431 
432 		if (user_priority && r->pref != rule->pref)
433 			continue;
434 
435 		if (rule->iifname[0] &&
436 		    memcmp(r->iifname, rule->iifname, IFNAMSIZ))
437 			continue;
438 
439 		if (rule->oifname[0] &&
440 		    memcmp(r->oifname, rule->oifname, IFNAMSIZ))
441 			continue;
442 
443 		if (rule->mark && r->mark != rule->mark)
444 			continue;
445 
446 		if (rule->suppress_ifgroup != -1 &&
447 		    r->suppress_ifgroup != rule->suppress_ifgroup)
448 			continue;
449 
450 		if (rule->suppress_prefixlen != -1 &&
451 		    r->suppress_prefixlen != rule->suppress_prefixlen)
452 			continue;
453 
454 		if (rule->mark_mask && r->mark_mask != rule->mark_mask)
455 			continue;
456 
457 		if (rule->tun_id && r->tun_id != rule->tun_id)
458 			continue;
459 
460 		if (r->fr_net != rule->fr_net)
461 			continue;
462 
463 		if (rule->l3mdev && r->l3mdev != rule->l3mdev)
464 			continue;
465 
466 		if (uid_range_set(&rule->uid_range) &&
467 		    (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
468 		    !uid_eq(r->uid_range.end, rule->uid_range.end)))
469 			continue;
470 
471 		if (rule->ip_proto && r->ip_proto != rule->ip_proto)
472 			continue;
473 
474 		if (rule->proto && r->proto != rule->proto)
475 			continue;
476 
477 		if (fib_rule_port_range_set(&rule->sport_range) &&
478 		    !fib_rule_port_range_compare(&r->sport_range,
479 						 &rule->sport_range))
480 			continue;
481 
482 		if (fib_rule_port_range_set(&rule->dport_range) &&
483 		    !fib_rule_port_range_compare(&r->dport_range,
484 						 &rule->dport_range))
485 			continue;
486 
487 		if (!ops->compare(r, frh, tb))
488 			continue;
489 		return r;
490 	}
491 
492 	return NULL;
493 }
494 
495 #ifdef CONFIG_NET_L3_MASTER_DEV
fib_nl2rule_l3mdev(struct nlattr * nla,struct fib_rule * nlrule,struct netlink_ext_ack * extack)496 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
497 			      struct netlink_ext_ack *extack)
498 {
499 	nlrule->l3mdev = nla_get_u8(nla);
500 	if (nlrule->l3mdev != 1) {
501 		NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
502 		return -1;
503 	}
504 
505 	return 0;
506 }
507 #else
fib_nl2rule_l3mdev(struct nlattr * nla,struct fib_rule * nlrule,struct netlink_ext_ack * extack)508 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
509 			      struct netlink_ext_ack *extack)
510 {
511 	NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
512 	return -1;
513 }
514 #endif
515 
fib_nl2rule(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack,struct fib_rules_ops * ops,struct nlattr * tb[],struct fib_rule ** rule,bool * user_priority)516 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
517 		       struct netlink_ext_ack *extack,
518 		       struct fib_rules_ops *ops,
519 		       struct nlattr *tb[],
520 		       struct fib_rule **rule,
521 		       bool *user_priority)
522 {
523 	struct net *net = sock_net(skb->sk);
524 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
525 	struct fib_rule *nlrule = NULL;
526 	int err = -EINVAL;
527 
528 	if (frh->src_len)
529 		if (!tb[FRA_SRC] ||
530 		    frh->src_len > (ops->addr_size * 8) ||
531 		    nla_len(tb[FRA_SRC]) != ops->addr_size) {
532 			NL_SET_ERR_MSG(extack, "Invalid source address");
533 			goto errout;
534 	}
535 
536 	if (frh->dst_len)
537 		if (!tb[FRA_DST] ||
538 		    frh->dst_len > (ops->addr_size * 8) ||
539 		    nla_len(tb[FRA_DST]) != ops->addr_size) {
540 			NL_SET_ERR_MSG(extack, "Invalid dst address");
541 			goto errout;
542 	}
543 
544 	nlrule = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
545 	if (!nlrule) {
546 		err = -ENOMEM;
547 		goto errout;
548 	}
549 	refcount_set(&nlrule->refcnt, 1);
550 	nlrule->fr_net = net;
551 
552 	if (tb[FRA_PRIORITY]) {
553 		nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
554 		*user_priority = true;
555 	} else {
556 		nlrule->pref = fib_default_rule_pref(ops);
557 	}
558 
559 	nlrule->proto = tb[FRA_PROTOCOL] ?
560 		nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
561 
562 	if (tb[FRA_IIFNAME]) {
563 		struct net_device *dev;
564 
565 		nlrule->iifindex = -1;
566 		nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
567 		dev = __dev_get_by_name(net, nlrule->iifname);
568 		if (dev)
569 			nlrule->iifindex = dev->ifindex;
570 	}
571 
572 	if (tb[FRA_OIFNAME]) {
573 		struct net_device *dev;
574 
575 		nlrule->oifindex = -1;
576 		nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
577 		dev = __dev_get_by_name(net, nlrule->oifname);
578 		if (dev)
579 			nlrule->oifindex = dev->ifindex;
580 	}
581 
582 	if (tb[FRA_FWMARK]) {
583 		nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
584 		if (nlrule->mark)
585 			/* compatibility: if the mark value is non-zero all bits
586 			 * are compared unless a mask is explicitly specified.
587 			 */
588 			nlrule->mark_mask = 0xFFFFFFFF;
589 	}
590 
591 	if (tb[FRA_FWMASK])
592 		nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
593 
594 	if (tb[FRA_TUN_ID])
595 		nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
596 
597 	err = -EINVAL;
598 	if (tb[FRA_L3MDEV] &&
599 	    fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
600 		goto errout_free;
601 
602 	nlrule->action = frh->action;
603 	nlrule->flags = frh->flags;
604 	nlrule->table = frh_get_table(frh, tb);
605 	if (tb[FRA_SUPPRESS_PREFIXLEN])
606 		nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
607 	else
608 		nlrule->suppress_prefixlen = -1;
609 
610 	if (tb[FRA_SUPPRESS_IFGROUP])
611 		nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
612 	else
613 		nlrule->suppress_ifgroup = -1;
614 
615 	if (tb[FRA_GOTO]) {
616 		if (nlrule->action != FR_ACT_GOTO) {
617 			NL_SET_ERR_MSG(extack, "Unexpected goto");
618 			goto errout_free;
619 		}
620 
621 		nlrule->target = nla_get_u32(tb[FRA_GOTO]);
622 		/* Backward jumps are prohibited to avoid endless loops */
623 		if (nlrule->target <= nlrule->pref) {
624 			NL_SET_ERR_MSG(extack, "Backward goto not supported");
625 			goto errout_free;
626 		}
627 	} else if (nlrule->action == FR_ACT_GOTO) {
628 		NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
629 		goto errout_free;
630 	}
631 
632 	if (nlrule->l3mdev && nlrule->table) {
633 		NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
634 		goto errout_free;
635 	}
636 
637 	if (tb[FRA_UID_RANGE]) {
638 		if (current_user_ns() != net->user_ns) {
639 			err = -EPERM;
640 			NL_SET_ERR_MSG(extack, "No permission to set uid");
641 			goto errout_free;
642 		}
643 
644 		nlrule->uid_range = nla_get_kuid_range(tb);
645 
646 		if (!uid_range_set(&nlrule->uid_range) ||
647 		    !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
648 			NL_SET_ERR_MSG(extack, "Invalid uid range");
649 			goto errout_free;
650 		}
651 	} else {
652 		nlrule->uid_range = fib_kuid_range_unset;
653 	}
654 
655 	if (tb[FRA_IP_PROTO])
656 		nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
657 
658 	if (tb[FRA_SPORT_RANGE]) {
659 		err = nla_get_port_range(tb[FRA_SPORT_RANGE],
660 					 &nlrule->sport_range);
661 		if (err) {
662 			NL_SET_ERR_MSG(extack, "Invalid sport range");
663 			goto errout_free;
664 		}
665 	}
666 
667 	if (tb[FRA_DPORT_RANGE]) {
668 		err = nla_get_port_range(tb[FRA_DPORT_RANGE],
669 					 &nlrule->dport_range);
670 		if (err) {
671 			NL_SET_ERR_MSG(extack, "Invalid dport range");
672 			goto errout_free;
673 		}
674 	}
675 
676 	*rule = nlrule;
677 
678 	return 0;
679 
680 errout_free:
681 	kfree(nlrule);
682 errout:
683 	return err;
684 }
685 
rule_exists(struct fib_rules_ops * ops,struct fib_rule_hdr * frh,struct nlattr ** tb,struct fib_rule * rule)686 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
687 		       struct nlattr **tb, struct fib_rule *rule)
688 {
689 	struct fib_rule *r;
690 
691 	list_for_each_entry(r, &ops->rules_list, list) {
692 		if (r->action != rule->action)
693 			continue;
694 
695 		if (r->table != rule->table)
696 			continue;
697 
698 		if (r->pref != rule->pref)
699 			continue;
700 
701 		if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
702 			continue;
703 
704 		if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
705 			continue;
706 
707 		if (r->mark != rule->mark)
708 			continue;
709 
710 		if (r->suppress_ifgroup != rule->suppress_ifgroup)
711 			continue;
712 
713 		if (r->suppress_prefixlen != rule->suppress_prefixlen)
714 			continue;
715 
716 		if (r->mark_mask != rule->mark_mask)
717 			continue;
718 
719 		if (r->tun_id != rule->tun_id)
720 			continue;
721 
722 		if (r->fr_net != rule->fr_net)
723 			continue;
724 
725 		if (r->l3mdev != rule->l3mdev)
726 			continue;
727 
728 		if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
729 		    !uid_eq(r->uid_range.end, rule->uid_range.end))
730 			continue;
731 
732 		if (r->ip_proto != rule->ip_proto)
733 			continue;
734 
735 		if (r->proto != rule->proto)
736 			continue;
737 
738 		if (!fib_rule_port_range_compare(&r->sport_range,
739 						 &rule->sport_range))
740 			continue;
741 
742 		if (!fib_rule_port_range_compare(&r->dport_range,
743 						 &rule->dport_range))
744 			continue;
745 
746 		if (!ops->compare(r, frh, tb))
747 			continue;
748 		return 1;
749 	}
750 	return 0;
751 }
752 
753 static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = {
754 	[FRA_UNSPEC]	= { .strict_start_type = FRA_DPORT_RANGE + 1 },
755 	[FRA_IIFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
756 	[FRA_OIFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
757 	[FRA_PRIORITY]	= { .type = NLA_U32 },
758 	[FRA_FWMARK]	= { .type = NLA_U32 },
759 	[FRA_FLOW]	= { .type = NLA_U32 },
760 	[FRA_TUN_ID]	= { .type = NLA_U64 },
761 	[FRA_FWMASK]	= { .type = NLA_U32 },
762 	[FRA_TABLE]     = { .type = NLA_U32 },
763 	[FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 },
764 	[FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 },
765 	[FRA_GOTO]	= { .type = NLA_U32 },
766 	[FRA_L3MDEV]	= { .type = NLA_U8 },
767 	[FRA_UID_RANGE]	= { .len = sizeof(struct fib_rule_uid_range) },
768 	[FRA_PROTOCOL]  = { .type = NLA_U8 },
769 	[FRA_IP_PROTO]  = { .type = NLA_U8 },
770 	[FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
771 	[FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) }
772 };
773 
fib_nl_newrule(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)774 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
775 		   struct netlink_ext_ack *extack)
776 {
777 	struct net *net = sock_net(skb->sk);
778 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
779 	struct fib_rules_ops *ops = NULL;
780 	struct fib_rule *rule = NULL, *r, *last = NULL;
781 	struct nlattr *tb[FRA_MAX + 1];
782 	int err = -EINVAL, unresolved = 0;
783 	bool user_priority = false;
784 
785 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
786 		NL_SET_ERR_MSG(extack, "Invalid msg length");
787 		goto errout;
788 	}
789 
790 	ops = lookup_rules_ops(net, frh->family);
791 	if (!ops) {
792 		err = -EAFNOSUPPORT;
793 		NL_SET_ERR_MSG(extack, "Rule family not supported");
794 		goto errout;
795 	}
796 
797 	err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
798 				     fib_rule_policy, extack);
799 	if (err < 0) {
800 		NL_SET_ERR_MSG(extack, "Error parsing msg");
801 		goto errout;
802 	}
803 
804 	err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
805 	if (err)
806 		goto errout;
807 
808 	if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
809 	    rule_exists(ops, frh, tb, rule)) {
810 		err = -EEXIST;
811 		goto errout_free;
812 	}
813 
814 	err = ops->configure(rule, skb, frh, tb, extack);
815 	if (err < 0)
816 		goto errout_free;
817 
818 	err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
819 				      extack);
820 	if (err < 0)
821 		goto errout_free;
822 
823 	list_for_each_entry(r, &ops->rules_list, list) {
824 		if (r->pref == rule->target) {
825 			RCU_INIT_POINTER(rule->ctarget, r);
826 			break;
827 		}
828 	}
829 
830 	if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
831 		unresolved = 1;
832 
833 	list_for_each_entry(r, &ops->rules_list, list) {
834 		if (r->pref > rule->pref)
835 			break;
836 		last = r;
837 	}
838 
839 	if (last)
840 		list_add_rcu(&rule->list, &last->list);
841 	else
842 		list_add_rcu(&rule->list, &ops->rules_list);
843 
844 	if (ops->unresolved_rules) {
845 		/*
846 		 * There are unresolved goto rules in the list, check if
847 		 * any of them are pointing to this new rule.
848 		 */
849 		list_for_each_entry(r, &ops->rules_list, list) {
850 			if (r->action == FR_ACT_GOTO &&
851 			    r->target == rule->pref &&
852 			    rtnl_dereference(r->ctarget) == NULL) {
853 				rcu_assign_pointer(r->ctarget, rule);
854 				if (--ops->unresolved_rules == 0)
855 					break;
856 			}
857 		}
858 	}
859 
860 	if (rule->action == FR_ACT_GOTO)
861 		ops->nr_goto_rules++;
862 
863 	if (unresolved)
864 		ops->unresolved_rules++;
865 
866 	if (rule->tun_id)
867 		ip_tunnel_need_metadata();
868 
869 	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
870 	flush_route_cache(ops);
871 	rules_ops_put(ops);
872 	return 0;
873 
874 errout_free:
875 	kfree(rule);
876 errout:
877 	rules_ops_put(ops);
878 	return err;
879 }
880 EXPORT_SYMBOL_GPL(fib_nl_newrule);
881 
fib_nl_delrule(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)882 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
883 		   struct netlink_ext_ack *extack)
884 {
885 	struct net *net = sock_net(skb->sk);
886 	struct fib_rule_hdr *frh = nlmsg_data(nlh);
887 	struct fib_rules_ops *ops = NULL;
888 	struct fib_rule *rule = NULL, *r, *nlrule = NULL;
889 	struct nlattr *tb[FRA_MAX+1];
890 	int err = -EINVAL;
891 	bool user_priority = false;
892 
893 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
894 		NL_SET_ERR_MSG(extack, "Invalid msg length");
895 		goto errout;
896 	}
897 
898 	ops = lookup_rules_ops(net, frh->family);
899 	if (ops == NULL) {
900 		err = -EAFNOSUPPORT;
901 		NL_SET_ERR_MSG(extack, "Rule family not supported");
902 		goto errout;
903 	}
904 
905 	err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
906 				     fib_rule_policy, extack);
907 	if (err < 0) {
908 		NL_SET_ERR_MSG(extack, "Error parsing msg");
909 		goto errout;
910 	}
911 
912 	err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
913 	if (err)
914 		goto errout;
915 
916 	rule = rule_find(ops, frh, tb, nlrule, user_priority);
917 	if (!rule) {
918 		err = -ENOENT;
919 		goto errout;
920 	}
921 
922 	if (rule->flags & FIB_RULE_PERMANENT) {
923 		err = -EPERM;
924 		goto errout;
925 	}
926 
927 	if (ops->delete) {
928 		err = ops->delete(rule);
929 		if (err)
930 			goto errout;
931 	}
932 
933 	if (rule->tun_id)
934 		ip_tunnel_unneed_metadata();
935 
936 	list_del_rcu(&rule->list);
937 
938 	if (rule->action == FR_ACT_GOTO) {
939 		ops->nr_goto_rules--;
940 		if (rtnl_dereference(rule->ctarget) == NULL)
941 			ops->unresolved_rules--;
942 	}
943 
944 	/*
945 	 * Check if this rule is a target to any of them. If so,
946 	 * adjust to the next one with the same preference or
947 	 * disable them. As this operation is eventually very
948 	 * expensive, it is only performed if goto rules, except
949 	 * current if it is goto rule, have actually been added.
950 	 */
951 	if (ops->nr_goto_rules > 0) {
952 		struct fib_rule *n;
953 
954 		n = list_next_entry(rule, list);
955 		if (&n->list == &ops->rules_list || n->pref != rule->pref)
956 			n = NULL;
957 		list_for_each_entry(r, &ops->rules_list, list) {
958 			if (rtnl_dereference(r->ctarget) != rule)
959 				continue;
960 			rcu_assign_pointer(r->ctarget, n);
961 			if (!n)
962 				ops->unresolved_rules++;
963 		}
964 	}
965 
966 	call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
967 				NULL);
968 	notify_rule_change(RTM_DELRULE, rule, ops, nlh,
969 			   NETLINK_CB(skb).portid);
970 	fib_rule_put(rule);
971 	flush_route_cache(ops);
972 	rules_ops_put(ops);
973 	kfree(nlrule);
974 	return 0;
975 
976 errout:
977 	kfree(nlrule);
978 	rules_ops_put(ops);
979 	return err;
980 }
981 EXPORT_SYMBOL_GPL(fib_nl_delrule);
982 
fib_rule_nlmsg_size(struct fib_rules_ops * ops,struct fib_rule * rule)983 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
984 					 struct fib_rule *rule)
985 {
986 	size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
987 			 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
988 			 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
989 			 + nla_total_size(4) /* FRA_PRIORITY */
990 			 + nla_total_size(4) /* FRA_TABLE */
991 			 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
992 			 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
993 			 + nla_total_size(4) /* FRA_FWMARK */
994 			 + nla_total_size(4) /* FRA_FWMASK */
995 			 + nla_total_size_64bit(8) /* FRA_TUN_ID */
996 			 + nla_total_size(sizeof(struct fib_kuid_range))
997 			 + nla_total_size(1) /* FRA_PROTOCOL */
998 			 + nla_total_size(1) /* FRA_IP_PROTO */
999 			 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
1000 			 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
1001 
1002 	if (ops->nlmsg_payload)
1003 		payload += ops->nlmsg_payload(rule);
1004 
1005 	return payload;
1006 }
1007 
fib_nl_fill_rule(struct sk_buff * skb,struct fib_rule * rule,u32 pid,u32 seq,int type,int flags,struct fib_rules_ops * ops)1008 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
1009 			    u32 pid, u32 seq, int type, int flags,
1010 			    struct fib_rules_ops *ops)
1011 {
1012 	struct nlmsghdr *nlh;
1013 	struct fib_rule_hdr *frh;
1014 
1015 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
1016 	if (nlh == NULL)
1017 		return -EMSGSIZE;
1018 
1019 	frh = nlmsg_data(nlh);
1020 	frh->family = ops->family;
1021 	frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT;
1022 	if (nla_put_u32(skb, FRA_TABLE, rule->table))
1023 		goto nla_put_failure;
1024 	if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
1025 		goto nla_put_failure;
1026 	frh->res1 = 0;
1027 	frh->res2 = 0;
1028 	frh->action = rule->action;
1029 	frh->flags = rule->flags;
1030 
1031 	if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
1032 		goto nla_put_failure;
1033 
1034 	if (rule->action == FR_ACT_GOTO &&
1035 	    rcu_access_pointer(rule->ctarget) == NULL)
1036 		frh->flags |= FIB_RULE_UNRESOLVED;
1037 
1038 	if (rule->iifname[0]) {
1039 		if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
1040 			goto nla_put_failure;
1041 		if (rule->iifindex == -1)
1042 			frh->flags |= FIB_RULE_IIF_DETACHED;
1043 	}
1044 
1045 	if (rule->oifname[0]) {
1046 		if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
1047 			goto nla_put_failure;
1048 		if (rule->oifindex == -1)
1049 			frh->flags |= FIB_RULE_OIF_DETACHED;
1050 	}
1051 
1052 	if ((rule->pref &&
1053 	     nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
1054 	    (rule->mark &&
1055 	     nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
1056 	    ((rule->mark_mask || rule->mark) &&
1057 	     nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
1058 	    (rule->target &&
1059 	     nla_put_u32(skb, FRA_GOTO, rule->target)) ||
1060 	    (rule->tun_id &&
1061 	     nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
1062 	    (rule->l3mdev &&
1063 	     nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
1064 	    (uid_range_set(&rule->uid_range) &&
1065 	     nla_put_uid_range(skb, &rule->uid_range)) ||
1066 	    (fib_rule_port_range_set(&rule->sport_range) &&
1067 	     nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
1068 	    (fib_rule_port_range_set(&rule->dport_range) &&
1069 	     nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
1070 	    (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
1071 		goto nla_put_failure;
1072 
1073 	if (rule->suppress_ifgroup != -1) {
1074 		if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
1075 			goto nla_put_failure;
1076 	}
1077 
1078 	if (ops->fill(rule, skb, frh) < 0)
1079 		goto nla_put_failure;
1080 
1081 	nlmsg_end(skb, nlh);
1082 	return 0;
1083 
1084 nla_put_failure:
1085 	nlmsg_cancel(skb, nlh);
1086 	return -EMSGSIZE;
1087 }
1088 
dump_rules(struct sk_buff * skb,struct netlink_callback * cb,struct fib_rules_ops * ops)1089 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
1090 		      struct fib_rules_ops *ops)
1091 {
1092 	int idx = 0;
1093 	struct fib_rule *rule;
1094 	int err = 0;
1095 
1096 	rcu_read_lock();
1097 	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
1098 		if (idx < cb->args[1])
1099 			goto skip;
1100 
1101 		err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
1102 				       cb->nlh->nlmsg_seq, RTM_NEWRULE,
1103 				       NLM_F_MULTI, ops);
1104 		if (err)
1105 			break;
1106 skip:
1107 		idx++;
1108 	}
1109 	rcu_read_unlock();
1110 	cb->args[1] = idx;
1111 	rules_ops_put(ops);
1112 
1113 	return err;
1114 }
1115 
fib_valid_dumprule_req(const struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1116 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
1117 				   struct netlink_ext_ack *extack)
1118 {
1119 	struct fib_rule_hdr *frh;
1120 
1121 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1122 		NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
1123 		return -EINVAL;
1124 	}
1125 
1126 	frh = nlmsg_data(nlh);
1127 	if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
1128 	    frh->res1 || frh->res2 || frh->action || frh->flags) {
1129 		NL_SET_ERR_MSG(extack,
1130 			       "Invalid values in header for fib rule dump request");
1131 		return -EINVAL;
1132 	}
1133 
1134 	if (nlmsg_attrlen(nlh, sizeof(*frh))) {
1135 		NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
1136 		return -EINVAL;
1137 	}
1138 
1139 	return 0;
1140 }
1141 
fib_nl_dumprule(struct sk_buff * skb,struct netlink_callback * cb)1142 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
1143 {
1144 	const struct nlmsghdr *nlh = cb->nlh;
1145 	struct net *net = sock_net(skb->sk);
1146 	struct fib_rules_ops *ops;
1147 	int idx = 0, family;
1148 
1149 	if (cb->strict_check) {
1150 		int err = fib_valid_dumprule_req(nlh, cb->extack);
1151 
1152 		if (err < 0)
1153 			return err;
1154 	}
1155 
1156 	family = rtnl_msg_family(nlh);
1157 	if (family != AF_UNSPEC) {
1158 		/* Protocol specific dump request */
1159 		ops = lookup_rules_ops(net, family);
1160 		if (ops == NULL)
1161 			return -EAFNOSUPPORT;
1162 
1163 		dump_rules(skb, cb, ops);
1164 
1165 		return skb->len;
1166 	}
1167 
1168 	rcu_read_lock();
1169 	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1170 		if (idx < cb->args[0] || !try_module_get(ops->owner))
1171 			goto skip;
1172 
1173 		if (dump_rules(skb, cb, ops) < 0)
1174 			break;
1175 
1176 		cb->args[1] = 0;
1177 skip:
1178 		idx++;
1179 	}
1180 	rcu_read_unlock();
1181 	cb->args[0] = idx;
1182 
1183 	return skb->len;
1184 }
1185 
notify_rule_change(int event,struct fib_rule * rule,struct fib_rules_ops * ops,struct nlmsghdr * nlh,u32 pid)1186 static void notify_rule_change(int event, struct fib_rule *rule,
1187 			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1188 			       u32 pid)
1189 {
1190 	struct net *net;
1191 	struct sk_buff *skb;
1192 	int err = -ENOMEM;
1193 
1194 	net = ops->fro_net;
1195 	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1196 	if (skb == NULL)
1197 		goto errout;
1198 
1199 	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1200 	if (err < 0) {
1201 		/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1202 		WARN_ON(err == -EMSGSIZE);
1203 		kfree_skb(skb);
1204 		goto errout;
1205 	}
1206 
1207 	rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1208 	return;
1209 errout:
1210 	if (err < 0)
1211 		rtnl_set_sk_err(net, ops->nlgroup, err);
1212 }
1213 
attach_rules(struct list_head * rules,struct net_device * dev)1214 static void attach_rules(struct list_head *rules, struct net_device *dev)
1215 {
1216 	struct fib_rule *rule;
1217 
1218 	list_for_each_entry(rule, rules, list) {
1219 		if (rule->iifindex == -1 &&
1220 		    strcmp(dev->name, rule->iifname) == 0)
1221 			rule->iifindex = dev->ifindex;
1222 		if (rule->oifindex == -1 &&
1223 		    strcmp(dev->name, rule->oifname) == 0)
1224 			rule->oifindex = dev->ifindex;
1225 	}
1226 }
1227 
detach_rules(struct list_head * rules,struct net_device * dev)1228 static void detach_rules(struct list_head *rules, struct net_device *dev)
1229 {
1230 	struct fib_rule *rule;
1231 
1232 	list_for_each_entry(rule, rules, list) {
1233 		if (rule->iifindex == dev->ifindex)
1234 			rule->iifindex = -1;
1235 		if (rule->oifindex == dev->ifindex)
1236 			rule->oifindex = -1;
1237 	}
1238 }
1239 
1240 
fib_rules_event(struct notifier_block * this,unsigned long event,void * ptr)1241 static int fib_rules_event(struct notifier_block *this, unsigned long event,
1242 			   void *ptr)
1243 {
1244 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1245 	struct net *net = dev_net(dev);
1246 	struct fib_rules_ops *ops;
1247 
1248 	ASSERT_RTNL();
1249 
1250 	switch (event) {
1251 	case NETDEV_REGISTER:
1252 		list_for_each_entry(ops, &net->rules_ops, list)
1253 			attach_rules(&ops->rules_list, dev);
1254 		break;
1255 
1256 	case NETDEV_CHANGENAME:
1257 		list_for_each_entry(ops, &net->rules_ops, list) {
1258 			detach_rules(&ops->rules_list, dev);
1259 			attach_rules(&ops->rules_list, dev);
1260 		}
1261 		break;
1262 
1263 	case NETDEV_UNREGISTER:
1264 		list_for_each_entry(ops, &net->rules_ops, list)
1265 			detach_rules(&ops->rules_list, dev);
1266 		break;
1267 	}
1268 
1269 	return NOTIFY_DONE;
1270 }
1271 
1272 static struct notifier_block fib_rules_notifier = {
1273 	.notifier_call = fib_rules_event,
1274 };
1275 
fib_rules_net_init(struct net * net)1276 static int __net_init fib_rules_net_init(struct net *net)
1277 {
1278 	INIT_LIST_HEAD(&net->rules_ops);
1279 	spin_lock_init(&net->rules_mod_lock);
1280 	return 0;
1281 }
1282 
fib_rules_net_exit(struct net * net)1283 static void __net_exit fib_rules_net_exit(struct net *net)
1284 {
1285 	WARN_ON_ONCE(!list_empty(&net->rules_ops));
1286 }
1287 
1288 static struct pernet_operations fib_rules_net_ops = {
1289 	.init = fib_rules_net_init,
1290 	.exit = fib_rules_net_exit,
1291 };
1292 
fib_rules_init(void)1293 static int __init fib_rules_init(void)
1294 {
1295 	int err;
1296 	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1297 	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1298 	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1299 
1300 	err = register_pernet_subsys(&fib_rules_net_ops);
1301 	if (err < 0)
1302 		goto fail;
1303 
1304 	err = register_netdevice_notifier(&fib_rules_notifier);
1305 	if (err < 0)
1306 		goto fail_unregister;
1307 
1308 	return 0;
1309 
1310 fail_unregister:
1311 	unregister_pernet_subsys(&fib_rules_net_ops);
1312 fail:
1313 	rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1314 	rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1315 	rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1316 	return err;
1317 }
1318 
1319 subsys_initcall(fib_rules_init);
1320