[net-next-2.6.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/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;

	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;
		nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ);
		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
14c0b97d TG	11	#include <linux/types.h>
	12	#include <linux/kernel.h>
	13	#include <linux/list.h>
	14	#include <net/fib_rules.h>
	15
	16	static LIST_HEAD(rules_ops);
	17	static DEFINE_SPINLOCK(rules_mod_lock);
	18
	19	static void notify_rule_change(int event, struct fib_rule *rule,
c17084d2 TG	20	struct fib_rules_ops ops, struct nlmsghdr nlh,
c17084d2 TG	21	u32 pid);
14c0b97d TG	22
	23	static struct fib_rules_ops *lookup_rules_ops(int family)
	24	{
	25	struct fib_rules_ops *ops;
	26
	27	rcu_read_lock();
	28	list_for_each_entry_rcu(ops, &rules_ops, list) {
	29	if (ops->family == family) {
	30	if (!try_module_get(ops->owner))
	31	ops = NULL;
	32	rcu_read_unlock();
	33	return ops;
	34	}
	35	}
	36	rcu_read_unlock();
	37
	38	return NULL;
	39	}
	40
	41	static void rules_ops_put(struct fib_rules_ops *ops)
	42	{
	43	if (ops)
	44	module_put(ops->owner);
	45	}
	46
	47	int fib_rules_register(struct fib_rules_ops *ops)
	48	{
	49	int err = -EEXIST;
	50	struct fib_rules_ops *o;
	51
	52	if (ops->rule_size < sizeof(struct fib_rule))
	53	return -EINVAL;
	54
	55	if (ops->match == NULL \|\| ops->configure == NULL \|\|
	56	ops->compare == NULL \|\| ops->fill == NULL \|\|
	57	ops->action == NULL)
	58	return -EINVAL;
	59
	60	spin_lock(&rules_mod_lock);
	61	list_for_each_entry(o, &rules_ops, list)
	62	if (ops->family == o->family)
	63	goto errout;
	64
	65	list_add_tail_rcu(&ops->list, &rules_ops);
	66	err = 0;
	67	errout:
	68	spin_unlock(&rules_mod_lock);
	69
	70	return err;
	71	}
	72
	73	EXPORT_SYMBOL_GPL(fib_rules_register);
	74
	75	static void cleanup_ops(struct fib_rules_ops *ops)
	76	{
	77	struct fib_rule rule, tmp;
	78
	79	list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
	80	list_del_rcu(&rule->list);
	81	fib_rule_put(rule);
	82	}
	83	}
	84
	85	int fib_rules_unregister(struct fib_rules_ops *ops)
86	{
87	int err = 0;
88	struct fib_rules_ops *o;
89
90	spin_lock(&rules_mod_lock);
91	list_for_each_entry(o, &rules_ops, list) {
92	if (o == ops) {
93	list_del_rcu(&o->list);
94	cleanup_ops(ops);
95	goto out;
96	}
97	}
98
99	err = -ENOENT;
100	out:
101	spin_unlock(&rules_mod_lock);
102
103	synchronize_rcu();
104
105	return err;
106	}
107
108	EXPORT_SYMBOL_GPL(fib_rules_unregister);
109
110	int fib_rules_lookup(struct fib_rules_ops ops, struct flowi fl,
111	int flags, struct fib_lookup_arg *arg)
112	{
113	struct fib_rule *rule;
114	int err;
115
116	rcu_read_lock();
117
118	list_for_each_entry_rcu(rule, ops->rules_list, list) {
119	if (rule->ifindex && (rule->ifindex != fl->iif))
120	continue;
121
122	if (!ops->match(rule, fl, flags))
123	continue;
124
125	err = ops->action(rule, fl, flags, arg);
126	if (err != -EAGAIN) {
127	fib_rule_get(rule);
128	arg->rule = rule;
129	goto out;
130	}
131	}
132
133	err = -ENETUNREACH;
134	out:
135	rcu_read_unlock();
136
137	return err;
138	}
139
140	EXPORT_SYMBOL_GPL(fib_rules_lookup);
141
142	int fib_nl_newrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
143	{
144	struct fib_rule_hdr *frh = nlmsg_data(nlh);
145	struct fib_rules_ops *ops = NULL;
146	struct fib_rule rule, r, *last = NULL;
147	struct nlattr *tb[FRA_MAX+1];
148	int err = -EINVAL;
149
150	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
151	goto errout;
152
153	ops = lookup_rules_ops(frh->family);
154	if (ops == NULL) {
155	err = EAFNOSUPPORT;
156	goto errout;
157	}
158
159	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
160	if (err < 0)
161	goto errout;
162
14c0b97d TG	163	rule = kzalloc(ops->rule_size, GFP_KERNEL);
	164	if (rule == NULL) {
	165	err = -ENOMEM;
	166	goto errout;
	167	}
	168
	169	if (tb[FRA_PRIORITY])
	170	rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
	171
	172	if (tb[FRA_IFNAME]) {
	173	struct net_device *dev;
	174
	175	rule->ifindex = -1;
5176f91e	176	nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ);
14c0b97d TG	177	dev = __dev_get_by_name(rule->ifname);
	178	if (dev)
	179	rule->ifindex = dev->ifindex;
	180	}
	181
	182	rule->action = frh->action;
	183	rule->flags = frh->flags;
9e762a4a	184	rule->table = frh_get_table(frh, tb);
14c0b97d TG	185
	186	if (!rule->pref && ops->default_pref)
	187	rule->pref = ops->default_pref();
	188
	189	err = ops->configure(rule, skb, nlh, frh, tb);
	190	if (err < 0)
	191	goto errout_free;
	192
	193	list_for_each_entry(r, ops->rules_list, list) {
	194	if (r->pref > rule->pref)
	195	break;
	196	last = r;
	197	}
	198
	199	fib_rule_get(rule);
	200
	201	if (last)
	202	list_add_rcu(&rule->list, &last->list);
	203	else
	204	list_add_rcu(&rule->list, ops->rules_list);
	205
c17084d2	206	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
14c0b97d TG	207	rules_ops_put(ops);
	208	return 0;
	209
	210	errout_free:
	211	kfree(rule);
	212	errout:
	213	rules_ops_put(ops);
	214	return err;
	215	}
	216
	217	int fib_nl_delrule(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	218	{
	219	struct fib_rule_hdr *frh = nlmsg_data(nlh);
	220	struct fib_rules_ops *ops = NULL;
	221	struct fib_rule *rule;
	222	struct nlattr *tb[FRA_MAX+1];
	223	int err = -EINVAL;
	224
	225	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
	226	goto errout;
	227
	228	ops = lookup_rules_ops(frh->family);
	229	if (ops == NULL) {
	230	err = EAFNOSUPPORT;
	231	goto errout;
	232	}
	233
	234	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
	235	if (err < 0)
	236	goto errout;
	237
	238	list_for_each_entry(rule, ops->rules_list, list) {
	239	if (frh->action && (frh->action != rule->action))
	240	continue;
	241
9e762a4a	242	if (frh->table && (frh_get_table(frh, tb) != rule->table))
14c0b97d TG	243	continue;
	244
	245	if (tb[FRA_PRIORITY] &&
	246	(rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
	247	continue;
	248
	249	if (tb[FRA_IFNAME] &&
	250	nla_strcmp(tb[FRA_IFNAME], rule->ifname))
	251	continue;
	252
	253	if (!ops->compare(rule, frh, tb))
	254	continue;
	255
	256	if (rule->flags & FIB_RULE_PERMANENT) {
	257	err = -EPERM;
	258	goto errout;
	259	}
	260
	261	list_del_rcu(&rule->list);
	262	synchronize_rcu();
c17084d2 TG	263	notify_rule_change(RTM_DELRULE, rule, ops, nlh,
c17084d2 TG	264	NETLINK_CB(skb).pid);
14c0b97d TG	265	fib_rule_put(rule);
	266	rules_ops_put(ops);
	267	return 0;
	268	}
	269
	270	err = -ENOENT;
	271	errout:
	272	rules_ops_put(ops);
	273	return err;
	274	}
	275
	276	static int fib_nl_fill_rule(struct sk_buff skb, struct fib_rule rule,
	277	u32 pid, u32 seq, int type, int flags,
	278	struct fib_rules_ops *ops)
	279	{
	280	struct nlmsghdr *nlh;
	281	struct fib_rule_hdr *frh;
	282
	283	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
	284	if (nlh == NULL)
	285	return -1;
	286
	287	frh = nlmsg_data(nlh);
	288	frh->table = rule->table;
9e762a4a	289	NLA_PUT_U32(skb, FRA_TABLE, rule->table);
14c0b97d TG	290	frh->res1 = 0;
	291	frh->res2 = 0;
	292	frh->action = rule->action;
	293	frh->flags = rule->flags;
	294
	295	if (rule->ifname[0])
	296	NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);
	297
	298	if (rule->pref)
	299	NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
	300
	301	if (ops->fill(rule, skb, nlh, frh) < 0)
	302	goto nla_put_failure;
	303
	304	return nlmsg_end(skb, nlh);
	305
	306	nla_put_failure:
	307	return nlmsg_cancel(skb, nlh);
	308	}
	309
	310	int fib_rules_dump(struct sk_buff skb, struct netlink_callback cb, int family)
	311	{
	312	int idx = 0;
	313	struct fib_rule *rule;
	314	struct fib_rules_ops *ops;
	315
	316	ops = lookup_rules_ops(family);
	317	if (ops == NULL)
	318	return -EAFNOSUPPORT;
	319
	320	rcu_read_lock();
	321	list_for_each_entry(rule, ops->rules_list, list) {
	322	if (idx < cb->args[0])
	323	goto skip;
	324
	325	if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
	326	cb->nlh->nlmsg_seq, RTM_NEWRULE,
	327	NLM_F_MULTI, ops) < 0)
	328	break;
	329	skip:
	330	idx++;
	331	}
	332	rcu_read_unlock();
	333	cb->args[0] = idx;
	334	rules_ops_put(ops);
	335
	336	return skb->len;
	337	}
	338
	339	EXPORT_SYMBOL_GPL(fib_rules_dump);
	340
	341	static void notify_rule_change(int event, struct fib_rule *rule,
c17084d2 TG	342	struct fib_rules_ops ops, struct nlmsghdr nlh,
c17084d2 TG	343	u32 pid)
14c0b97d	344	{
c17084d2 TG	345	struct sk_buff *skb;
c17084d2 TG	346	int err = -ENOBUFS;
14c0b97d	347
c17084d2	348	skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
14c0b97d	349	if (skb == NULL)
c17084d2 TG	350	goto errout;
	351
	352	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
	353	if (err < 0) {
14c0b97d	354	kfree_skb(skb);
c17084d2 TG	355	goto errout;
	356	}
	357
	358	err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
	359	errout:
	360	if (err < 0)
	361	rtnl_set_sk_err(ops->nlgroup, err);
14c0b97d TG	362	}
	363
	364	static void attach_rules(struct list_head rules, struct net_device dev)
	365	{
	366	struct fib_rule *rule;
	367
	368	list_for_each_entry(rule, rules, list) {
	369	if (rule->ifindex == -1 &&
	370	strcmp(dev->name, rule->ifname) == 0)
	371	rule->ifindex = dev->ifindex;
	372	}
	373	}
	374
	375	static void detach_rules(struct list_head rules, struct net_device dev)
	376	{
	377	struct fib_rule *rule;
	378
	379	list_for_each_entry(rule, rules, list)
	380	if (rule->ifindex == dev->ifindex)
	381	rule->ifindex = -1;
	382	}
	383
	384
	385	static int fib_rules_event(struct notifier_block *this, unsigned long event,
	386	void *ptr)
	387	{
	388	struct net_device *dev = ptr;
	389	struct fib_rules_ops *ops;
	390
	391	ASSERT_RTNL();
	392	rcu_read_lock();
	393
	394	switch (event) {
	395	case NETDEV_REGISTER:
	396	list_for_each_entry(ops, &rules_ops, list)
	397	attach_rules(ops->rules_list, dev);
	398	break;
	399
	400	case NETDEV_UNREGISTER:
	401	list_for_each_entry(ops, &rules_ops, list)
	402	detach_rules(ops->rules_list, dev);
	403	break;
	404	}
	405
	406	rcu_read_unlock();
	407
	408	return NOTIFY_DONE;
	409	}
	410
	411	static struct notifier_block fib_rules_notifier = {
	412	.notifier_call = fib_rules_event,
	413	};
	414
	415	static int __init fib_rules_init(void)
	416	{
	417	return register_netdevice_notifier(&fib_rules_notifier);
	418	}
	419
	420	subsys_initcall(fib_rules_init);