[deliverable/linux.git] / net / core / fib_rules.c

/*
 * net/core/fib_rules.c		Generic Routing Rules
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation, version 2.
 *
 * Authors:	Thomas Graf <tgraf@suug.ch>
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <net/fib_rules.h>

static LIST_HEAD(rules_ops);
static DEFINE_SPINLOCK(rules_mod_lock);

static void notify_rule_change(int event, struct fib_rule *rule,
			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
			       u32 pid);

static struct fib_rules_ops *lookup_rules_ops(int family)
{
	struct fib_rules_ops *ops;

	rcu_read_lock();
	list_for_each_entry_rcu(ops, &rules_ops, list) {
		if (ops->family == family) {
			if (!try_module_get(ops->owner))
				ops = NULL;
			rcu_read_unlock();
			return ops;
		}
	}
	rcu_read_unlock();

	return NULL;
}

static void rules_ops_put(struct fib_rules_ops *ops)
{
	if (ops)
		module_put(ops->owner);
}

int fib_rules_register(struct fib_rules_ops *ops)
{
	int err = -EEXIST;
	struct fib_rules_ops *o;

	if (ops->rule_size < sizeof(struct fib_rule))
		return -EINVAL;

	if (ops->match == NULL || ops->configure == NULL ||
	    ops->compare == NULL || ops->fill == NULL ||
	    ops->action == NULL)
		return -EINVAL;

	spin_lock(&rules_mod_lock);
	list_for_each_entry(o, &rules_ops, list)
		if (ops->family == o->family)
			goto errout;

	list_add_tail_rcu(&ops->list, &rules_ops);
	err = 0;
errout:
	spin_unlock(&rules_mod_lock);

	return err;
}

EXPORT_SYMBOL_GPL(fib_rules_register);

static void cleanup_ops(struct fib_rules_ops *ops)
{
	struct fib_rule *rule, *tmp;

	list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
		list_del_rcu(&rule->list);
		fib_rule_put(rule);
	}
}

int fib_rules_unregister(struct fib_rules_ops *ops)
{
	int err = 0;
	struct fib_rules_ops *o;

	spin_lock(&rules_mod_lock);
	list_for_each_entry(o, &rules_ops, list) {
		if (o == ops) {
			list_del_rcu(&o->list);
			cleanup_ops(ops);
			goto out;
		}
	}

	err = -ENOENT;
out:
	spin_unlock(&rules_mod_lock);

	synchronize_rcu();

	return err;
}

EXPORT_SYMBOL_GPL(fib_rules_unregister);

int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
		     int flags, struct fib_lookup_arg *arg)
{
	struct fib_rule *rule;
	int err;

	rcu_read_lock();

	list_for_each_entry_rcu(rule, ops->rules_list, list) {
		if (rule->ifindex && (rule->ifindex != fl->iif))
			continue;

		if (!ops->match(rule, fl, flags))
			continue;

		err = ops->action(rule, fl, flags, arg);
		if (err != -EAGAIN) {
			fib_rule_get(rule);
			arg->rule = rule;
			goto out;
		}
	}

	err = -ENETUNREACH;
out:
	rcu_read_unlock();

	return err;
}

EXPORT_SYMBOL_GPL(fib_rules_lookup);

int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
	struct fib_rule_hdr *frh = nlmsg_data(nlh);
	struct fib_rules_ops *ops = NULL;
	struct fib_rule *rule, *r, *last = NULL;
	struct nlattr *tb[FRA_MAX+1];
	int err = -EINVAL;

	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
		goto errout;

	ops = lookup_rules_ops(frh->family);
	if (ops == NULL) {
		err = EAFNOSUPPORT;
		goto errout;
	}

	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
	if (err < 0)
		goto errout;

	if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
		goto errout;

	rule = kzalloc(ops->rule_size, GFP_KERNEL);
	if (rule == NULL) {
		err = -ENOMEM;
		goto errout;
	}

	if (tb[FRA_PRIORITY])
		rule->pref = nla_get_u32(tb[FRA_PRIORITY]);

	if (tb[FRA_IFNAME]) {
		struct net_device *dev;

		rule->ifindex = -1;
		if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
				IFNAMSIZ) >= IFNAMSIZ)
			goto errout_free;

		dev = __dev_get_by_name(rule->ifname);
		if (dev)
			rule->ifindex = dev->ifindex;
	}

	rule->action = frh->action;
	rule->flags = frh->flags;
	rule->table = frh_get_table(frh, tb);

	if (!rule->pref && ops->default_pref)
		rule->pref = ops->default_pref();

	err = ops->configure(rule, skb, nlh, frh, tb);
	if (err < 0)
		goto errout_free;

	list_for_each_entry(r, ops->rules_list, list) {
		if (r->pref > rule->pref)
			break;
		last = r;
	}

	fib_rule_get(rule);

	if (last)
		list_add_rcu(&rule->list, &last->list);
	else
		list_add_rcu(&rule->list, ops->rules_list);

	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
	rules_ops_put(ops);
	return 0;

errout_free:
	kfree(rule);
errout:
	rules_ops_put(ops);
	return err;
}

int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
	struct fib_rule_hdr *frh = nlmsg_data(nlh);
	struct fib_rules_ops *ops = NULL;
	struct fib_rule *rule;
	struct nlattr *tb[FRA_MAX+1];
	int err = -EINVAL;

	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
		goto errout;

	ops = lookup_rules_ops(frh->family);
	if (ops == NULL) {
		err = EAFNOSUPPORT;
		goto errout;
	}

	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
	if (err < 0)
		goto errout;

	list_for_each_entry(rule, ops->rules_list, list) {
		if (frh->action && (frh->action != rule->action))
			continue;

		if (frh->table && (frh_get_table(frh, tb) != rule->table))
			continue;

		if (tb[FRA_PRIORITY] &&
		    (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
			continue;

		if (tb[FRA_IFNAME] &&
		    nla_strcmp(tb[FRA_IFNAME], rule->ifname))
			continue;

		if (!ops->compare(rule, frh, tb))
			continue;

		if (rule->flags & FIB_RULE_PERMANENT) {
			err = -EPERM;
			goto errout;
		}

		list_del_rcu(&rule->list);
		synchronize_rcu();
		notify_rule_change(RTM_DELRULE, rule, ops, nlh,
				   NETLINK_CB(skb).pid);
		fib_rule_put(rule);
		rules_ops_put(ops);
		return 0;
	}

	err = -ENOENT;
errout:
	rules_ops_put(ops);
	return err;
}

static int 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)
{
	struct nlmsghdr *nlh;
	struct fib_rule_hdr *frh;

	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
	if (nlh == NULL)
		return -1;

	frh = nlmsg_data(nlh);
	frh->table = rule->table;
	NLA_PUT_U32(skb, FRA_TABLE, rule->table);
	frh->res1 = 0;
	frh->res2 = 0;
	frh->action = rule->action;
	frh->flags = rule->flags;

	if (rule->ifname[0])
		NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);

	if (rule->pref)
		NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);

	if (ops->fill(rule, skb, nlh, frh) < 0)
		goto nla_put_failure;

	return nlmsg_end(skb, nlh);

nla_put_failure:
	return nlmsg_cancel(skb, nlh);
}

int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
{
	int idx = 0;
	struct fib_rule *rule;
	struct fib_rules_ops *ops;

	ops = lookup_rules_ops(family);
	if (ops == NULL)
		return -EAFNOSUPPORT;

	rcu_read_lock();
	list_for_each_entry(rule, ops->rules_list, list) {
		if (idx < cb->args[0])
			goto skip;

		if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
				     cb->nlh->nlmsg_seq, RTM_NEWRULE,
				     NLM_F_MULTI, ops) < 0)
			break;
skip:
		idx++;
	}
	rcu_read_unlock();
	cb->args[0] = idx;
	rules_ops_put(ops);

	return skb->len;
}

EXPORT_SYMBOL_GPL(fib_rules_dump);

static void notify_rule_change(int event, struct fib_rule *rule,
			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
			       u32 pid)
{
	struct sk_buff *skb;
	int err = -ENOBUFS;

	skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (skb == NULL)
		goto errout;

	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
	if (err < 0) {
		kfree_skb(skb);
		goto errout;
	}

	err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
errout:
	if (err < 0)
		rtnl_set_sk_err(ops->nlgroup, err);
}

static void attach_rules(struct list_head *rules, struct net_device *dev)
{
	struct fib_rule *rule;

	list_for_each_entry(rule, rules, list) {
		if (rule->ifindex == -1 &&
		    strcmp(dev->name, rule->ifname) == 0)
			rule->ifindex = dev->ifindex;
	}
}

static void detach_rules(struct list_head *rules, struct net_device *dev)
{
	struct fib_rule *rule;

	list_for_each_entry(rule, rules, list)
		if (rule->ifindex == dev->ifindex)
			rule->ifindex = -1;
}


static int fib_rules_event(struct notifier_block *this, unsigned long event,
			    void *ptr)
{
	struct net_device *dev = ptr;
	struct fib_rules_ops *ops;

	ASSERT_RTNL();
	rcu_read_lock();

	switch (event) {
	case NETDEV_REGISTER:
		list_for_each_entry(ops, &rules_ops, list)
			attach_rules(ops->rules_list, dev);
		break;

	case NETDEV_UNREGISTER:
		list_for_each_entry(ops, &rules_ops, list)
			detach_rules(ops->rules_list, dev);
		break;
	}

	rcu_read_unlock();

	return NOTIFY_DONE;
}

static struct notifier_block fib_rules_notifier = {
	.notifier_call = fib_rules_event,
};

static int __init fib_rules_init(void)
{
	return register_netdevice_notifier(&fib_rules_notifier);
}

subsys_initcall(fib_rules_init);
Commit	Line	Data
14c0b97d TG	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/config.h>
	12	#include <linux/types.h>
	13	#include <linux/kernel.h>
	14	#include <linux/list.h>
	15	#include <net/fib_rules.h>
	16
	17	static LIST_HEAD(rules_ops);
	18	static DEFINE_SPINLOCK(rules_mod_lock);
	19
	20	static void notify_rule_change(int event, struct fib_rule *rule,
c17084d2 TG	21	struct fib_rules_ops ops, struct nlmsghdr nlh,
c17084d2 TG	22	u32 pid);
14c0b97d TG	23
	24	static struct fib_rules_ops *lookup_rules_ops(int family)
	25	{
	26	struct fib_rules_ops *ops;
	27
	28	rcu_read_lock();
	29	list_for_each_entry_rcu(ops, &rules_ops, list) {
	30	if (ops->family == family) {
	31	if (!try_module_get(ops->owner))
	32	ops = NULL;
	33	rcu_read_unlock();
	34	return ops;
	35	}
	36	}
	37	rcu_read_unlock();
	38
	39	return NULL;
	40	}
	41
	42	static void rules_ops_put(struct fib_rules_ops *ops)
	43	{
	44	if (ops)
	45	module_put(ops->owner);
	46	}
	47
	48	int fib_rules_register(struct fib_rules_ops *ops)
	49	{
	50	int err = -EEXIST;
	51	struct fib_rules_ops *o;
	52
	53	if (ops->rule_size < sizeof(struct fib_rule))
	54	return -EINVAL;
	55
	56	if (ops->match == NULL \|\| ops->configure == NULL \|\|
	57	ops->compare == NULL \|\| ops->fill == NULL \|\|
	58	ops->action == NULL)
	59	return -EINVAL;
	60
	61	spin_lock(&rules_mod_lock);
	62	list_for_each_entry(o, &rules_ops, list)
	63	if (ops->family == o->family)
	64	goto errout;
	65
	66	list_add_tail_rcu(&ops->list, &rules_ops);
	67	err = 0;
	68	errout:
	69	spin_unlock(&rules_mod_lock);
	70
	71	return err;
	72	}
	73
	74	EXPORT_SYMBOL_GPL(fib_rules_register);
	75
	76	static void cleanup_ops(struct fib_rules_ops *ops)
	77	{
	78	struct fib_rule rule, tmp;
	79
	80	list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
	81	list_del_rcu(&rule->list);
	82	fib_rule_put(rule);
	83	}
	84	}
	85
	86	int fib_rules_unregister(struct fib_rules_ops *ops)
87	{
88	int err = 0;
89	struct fib_rules_ops *o;
90
91	spin_lock(&rules_mod_lock);
92	list_for_each_entry(o, &rules_ops, list) {
93	if (o == ops) {
94	list_del_rcu(&o->list);
95	cleanup_ops(ops);
96	goto out;
97	}
98	}
99
100	err = -ENOENT;
101	out:
102	spin_unlock(&rules_mod_lock);
103
104	synchronize_rcu();
105
106	return err;
107	}
108
109	EXPORT_SYMBOL_GPL(fib_rules_unregister);
110
111	int fib_rules_lookup(struct fib_rules_ops ops, struct flowi fl,
112	int flags, struct fib_lookup_arg *arg)
113	{
114	struct fib_rule *rule;
115	int err;
116
117	rcu_read_lock();
118
119	list_for_each_entry_rcu(rule, ops->rules_list, list) {
120	if (rule->ifindex && (rule->ifindex != fl->iif))
121	continue;
122
123	if (!ops->match(rule, fl, flags))
124	continue;
125
126	err = ops->action(rule, fl, flags, arg);
127	if (err != -EAGAIN) {
128	fib_rule_get(rule);
129	arg->rule = rule;
130	goto out;
131	}
132	}
133
134	err = -ENETUNREACH;
135	out:
136	rcu_read_unlock();
137
138	return err;
139	}
140
141	EXPORT_SYMBOL_GPL(fib_rules_lookup);
142
143	int fib_nl_newrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
144	{
145	struct fib_rule_hdr *frh = nlmsg_data(nlh);
146	struct fib_rules_ops *ops = NULL;
147	struct fib_rule rule, r, *last = NULL;
148	struct nlattr *tb[FRA_MAX+1];
149	int err = -EINVAL;
150
151	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
152	goto errout;
153
154	ops = lookup_rules_ops(frh->family);
155	if (ops == NULL) {
156	err = EAFNOSUPPORT;
157	goto errout;
158	}
159
160	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
161	if (err < 0)
162	goto errout;
163
164	if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
165	goto errout;
166
167	rule = kzalloc(ops->rule_size, GFP_KERNEL);
168	if (rule == NULL) {
169	err = -ENOMEM;
170	goto errout;
171	}
172
173	if (tb[FRA_PRIORITY])
174	rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
175
176	if (tb[FRA_IFNAME]) {
177	struct net_device *dev;
178
179	rule->ifindex = -1;
180	if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
181	IFNAMSIZ) >= IFNAMSIZ)
182	goto errout_free;
183
184	dev = __dev_get_by_name(rule->ifname);
185	if (dev)
186	rule->ifindex = dev->ifindex;
187	}
188
189	rule->action = frh->action;
190	rule->flags = frh->flags;
9e762a4a	191	rule->table = frh_get_table(frh, tb);
14c0b97d TG	192
	193	if (!rule->pref && ops->default_pref)
	194	rule->pref = ops->default_pref();
	195
	196	err = ops->configure(rule, skb, nlh, frh, tb);
	197	if (err < 0)
	198	goto errout_free;
	199
	200	list_for_each_entry(r, ops->rules_list, list) {
	201	if (r->pref > rule->pref)
	202	break;
	203	last = r;
	204	}
	205
	206	fib_rule_get(rule);
	207
	208	if (last)
	209	list_add_rcu(&rule->list, &last->list);
	210	else
	211	list_add_rcu(&rule->list, ops->rules_list);
	212
c17084d2	213	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
14c0b97d TG	214	rules_ops_put(ops);
	215	return 0;
	216
	217	errout_free:
	218	kfree(rule);
	219	errout:
	220	rules_ops_put(ops);
	221	return err;
	222	}
	223
	224	int fib_nl_delrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	225	{
	226	struct fib_rule_hdr *frh = nlmsg_data(nlh);
	227	struct fib_rules_ops *ops = NULL;
	228	struct fib_rule *rule;
	229	struct nlattr *tb[FRA_MAX+1];
	230	int err = -EINVAL;
	231
	232	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
	233	goto errout;
	234
	235	ops = lookup_rules_ops(frh->family);
	236	if (ops == NULL) {
	237	err = EAFNOSUPPORT;
	238	goto errout;
	239	}
	240
	241	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
	242	if (err < 0)
	243	goto errout;
	244
	245	list_for_each_entry(rule, ops->rules_list, list) {
	246	if (frh->action && (frh->action != rule->action))
	247	continue;
	248
9e762a4a	249	if (frh->table && (frh_get_table(frh, tb) != rule->table))
14c0b97d TG	250	continue;
	251
	252	if (tb[FRA_PRIORITY] &&
	253	(rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
	254	continue;
	255
	256	if (tb[FRA_IFNAME] &&
	257	nla_strcmp(tb[FRA_IFNAME], rule->ifname))
	258	continue;
	259
	260	if (!ops->compare(rule, frh, tb))
	261	continue;
	262
	263	if (rule->flags & FIB_RULE_PERMANENT) {
	264	err = -EPERM;
	265	goto errout;
	266	}
	267
	268	list_del_rcu(&rule->list);
	269	synchronize_rcu();
c17084d2 TG	270	notify_rule_change(RTM_DELRULE, rule, ops, nlh,
c17084d2 TG	271	NETLINK_CB(skb).pid);
14c0b97d TG	272	fib_rule_put(rule);
	273	rules_ops_put(ops);
	274	return 0;
	275	}
	276
	277	err = -ENOENT;
	278	errout:
	279	rules_ops_put(ops);
	280	return err;
	281	}
	282
	283	static int fib_nl_fill_rule(struct sk_buff skb, struct fib_rule rule,
	284	u32 pid, u32 seq, int type, int flags,
	285	struct fib_rules_ops *ops)
	286	{
	287	struct nlmsghdr *nlh;
	288	struct fib_rule_hdr *frh;
	289
	290	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
	291	if (nlh == NULL)
	292	return -1;
	293
	294	frh = nlmsg_data(nlh);
	295	frh->table = rule->table;
9e762a4a	296	NLA_PUT_U32(skb, FRA_TABLE, rule->table);
14c0b97d TG	297	frh->res1 = 0;
	298	frh->res2 = 0;
	299	frh->action = rule->action;
	300	frh->flags = rule->flags;
	301
	302	if (rule->ifname[0])
	303	NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);
	304
	305	if (rule->pref)
	306	NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
	307
	308	if (ops->fill(rule, skb, nlh, frh) < 0)
	309	goto nla_put_failure;
	310
	311	return nlmsg_end(skb, nlh);
	312
	313	nla_put_failure:
	314	return nlmsg_cancel(skb, nlh);
	315	}
	316
	317	int fib_rules_dump(struct sk_buff skb, struct netlink_callback cb, int family)
	318	{
	319	int idx = 0;
	320	struct fib_rule *rule;
	321	struct fib_rules_ops *ops;
	322
	323	ops = lookup_rules_ops(family);
	324	if (ops == NULL)
	325	return -EAFNOSUPPORT;
	326
	327	rcu_read_lock();
	328	list_for_each_entry(rule, ops->rules_list, list) {
	329	if (idx < cb->args[0])
	330	goto skip;
	331
	332	if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
	333	cb->nlh->nlmsg_seq, RTM_NEWRULE,
	334	NLM_F_MULTI, ops) < 0)
	335	break;
	336	skip:
	337	idx++;
	338	}
	339	rcu_read_unlock();
	340	cb->args[0] = idx;
	341	rules_ops_put(ops);
	342
	343	return skb->len;
	344	}
	345
	346	EXPORT_SYMBOL_GPL(fib_rules_dump);
	347
	348	static void notify_rule_change(int event, struct fib_rule *rule,
c17084d2 TG	349	struct fib_rules_ops ops, struct nlmsghdr nlh,
c17084d2 TG	350	u32 pid)
14c0b97d	351	{
c17084d2 TG	352	struct sk_buff *skb;
c17084d2 TG	353	int err = -ENOBUFS;
14c0b97d	354
c17084d2	355	skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
14c0b97d	356	if (skb == NULL)
c17084d2 TG	357	goto errout;
	358
	359	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
	360	if (err < 0) {
14c0b97d	361	kfree_skb(skb);
c17084d2 TG	362	goto errout;
	363	}
	364
	365	err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
	366	errout:
	367	if (err < 0)
	368	rtnl_set_sk_err(ops->nlgroup, err);
14c0b97d TG	369	}
	370
	371	static void attach_rules(struct list_head rules, struct net_device dev)
	372	{
	373	struct fib_rule *rule;
	374
	375	list_for_each_entry(rule, rules, list) {
	376	if (rule->ifindex == -1 &&
	377	strcmp(dev->name, rule->ifname) == 0)
	378	rule->ifindex = dev->ifindex;
	379	}
	380	}
	381
	382	static void detach_rules(struct list_head rules, struct net_device dev)
	383	{
	384	struct fib_rule *rule;
	385
	386	list_for_each_entry(rule, rules, list)
	387	if (rule->ifindex == dev->ifindex)
	388	rule->ifindex = -1;
	389	}
	390
	391
	392	static int fib_rules_event(struct notifier_block *this, unsigned long event,
	393	void *ptr)
	394	{
	395	struct net_device *dev = ptr;
	396	struct fib_rules_ops *ops;
	397
	398	ASSERT_RTNL();
	399	rcu_read_lock();
	400
	401	switch (event) {
	402	case NETDEV_REGISTER:
	403	list_for_each_entry(ops, &rules_ops, list)
	404	attach_rules(ops->rules_list, dev);
	405	break;
	406
	407	case NETDEV_UNREGISTER:
	408	list_for_each_entry(ops, &rules_ops, list)
	409	detach_rules(ops->rules_list, dev);
	410	break;
	411	}
	412
	413	rcu_read_unlock();
	414
	415	return NOTIFY_DONE;
	416	}
	417
	418	static struct notifier_block fib_rules_notifier = {
	419	.notifier_call = fib_rules_event,
	420	};
	421
	422	static int __init fib_rules_init(void)
	423	{
	424	return register_netdevice_notifier(&fib_rules_notifier);
	425	}
	426
	427	subsys_initcall(fib_rules_init);