Release 4.11 net/sched/act_api.c

/*
 * net/sched/act_api.c  Packet action API.
 *
 *              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; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Author:      Jamal Hadi Salim
 *
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/sch_generic.h>
#include <net/pkt_cls.h>
#include <net/act_api.h>
#include <net/netlink.h>



static void free_tcf(struct rcu_head *head)
{
	struct tc_action *p = container_of(head, struct tc_action, tcfa_rcu);

	free_percpu(p->cpu_bstats);
	free_percpu(p->cpu_qstats);

	if (p->act_cookie) {
		kfree(p->act_cookie->data);
		kfree(p->act_cookie);
	}

	kfree(p);
}

Contributors
Person
Tokens
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Commits
CommitProp
Eric Dumazet
42
60.87%
1
33.33%
Jamal Hadi Salim
24
34.78%
1
33.33%
Américo Wang
3
4.35%
1
33.33%
Total
69
100.00%
3
100.00%



static void tcf_hash_destroy(struct tcf_hashinfo *hinfo, struct tc_action *p)
{
	spin_lock_bh(&hinfo->lock);
	hlist_del(&p->tcfa_head);
	spin_unlock_bh(&hinfo->lock);
	gen_kill_estimator(&p->tcfa_rate_est);
	/*
         * gen_estimator est_timer() might access p->tcfa_lock
         * or bstats, wait a RCU grace period before freeing p
         */
	call_rcu(&p->tcfa_rcu, free_tcf);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
31
52.54%
1
12.50%
Américo Wang
22
37.29%
5
62.50%
Eric Dumazet
5
8.47%
1
12.50%
Alexei Starovoitov
1
1.69%
1
12.50%
Total
59
100.00%
8
100.00%



int __tcf_hash_release(struct tc_action *p, bool bind, bool strict)
{
	int ret = 0;

	if (p) {
		if (bind)
			p->tcfa_bindcnt--;
		else if (strict && p->tcfa_bindcnt > 0)
			return -EPERM;

		p->tcfa_refcnt--;
		if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
			if (p->ops->cleanup)
				p->ops->cleanup(p, bind);
			tcf_hash_destroy(p->hinfo, p);
			ret = ACT_P_DELETED;
		}
	}

	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
56
52.34%
1
12.50%
Américo Wang
44
41.12%
6
75.00%
Daniel Borkmann
7
6.54%
1
12.50%
Total
107
100.00%
8
100.00%


EXPORT_SYMBOL(__tcf_hash_release);



static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
			   struct netlink_callback *cb)
{
	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
	struct nlattr *nest;

	spin_lock_bh(&hinfo->lock);

	s_i = cb->args[0];

	for (i = 0; i < (hinfo->hmask + 1); i++) {
		struct hlist_head *head;
		struct tc_action *p;

		head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];

		hlist_for_each_entry_rcu(p, head, tcfa_head) {
			index++;
			if (index < s_i)
				continue;

			nest = nla_nest_start(skb, n_i);
			if (nest == NULL)
				goto nla_put_failure;
			err = tcf_action_dump_1(skb, p, 0, 0);
			if (err < 0) {
				index--;
				nlmsg_trim(skb, nest);
				goto done;
			}
			nla_nest_end(skb, nest);
			n_i++;
			if (n_i >= TCA_ACT_MAX_PRIO)
				goto done;
		}
	}
done:
	spin_unlock_bh(&hinfo->lock);
	if (n_i)
		cb->args[0] += n_i;
	return n_i;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	goto done;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
184
76.03%
1
8.33%
Américo Wang
33
13.64%
6
50.00%
Patrick McHardy
20
8.26%
2
16.67%
Arnaldo Carvalho de Melo
3
1.24%
2
16.67%
Jamal Hadi Salim
2
0.83%
1
8.33%
Total
242
100.00%
12
100.00%



static int tcf_del_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
			  const struct tc_action_ops *ops)
{
	struct nlattr *nest;
	int i = 0, n_i = 0;
	int ret = -EINVAL;

	nest = nla_nest_start(skb, 0);
	if (nest == NULL)
		goto nla_put_failure;
	if (nla_put_string(skb, TCA_KIND, ops->kind))
		goto nla_put_failure;
	for (i = 0; i < (hinfo->hmask + 1); i++) {
		struct hlist_head *head;
		struct hlist_node *n;
		struct tc_action *p;

		head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
		hlist_for_each_entry_safe(p, n, head, tcfa_head) {
			ret = __tcf_hash_release(p, false, true);
			if (ret == ACT_P_DELETED) {
				module_put(p->ops->owner);
				n_i++;
			} else if (ret < 0)
				goto nla_put_failure;
		}
	}
	if (nla_put_u32(skb, TCA_FCNT, n_i))
		goto nla_put_failure;
	nla_nest_end(skb, nest);

	return n_i;
nla_put_failure:
	nla_nest_cancel(skb, nest);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
126
57.80%
2
15.38%
Américo Wang
65
29.82%
6
46.15%
Patrick McHardy
19
8.72%
2
15.38%
Daniel Borkmann
4
1.83%
1
7.69%
Jamal Hadi Salim
2
0.92%
1
7.69%
Arnaldo Carvalho de Melo
2
0.92%
1
7.69%
Total
218
100.00%
13
100.00%



int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
		       struct netlink_callback *cb, int type,
		       const struct tc_action_ops *ops)
{
	struct tcf_hashinfo *hinfo = tn->hinfo;

	if (type == RTM_DELACTION) {
		return tcf_del_walker(hinfo, skb, ops);
	} else if (type == RTM_GETACTION) {
		return tcf_dump_walker(hinfo, skb, cb);
	} else {
		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
		return -EINVAL;
	}
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
66
72.53%
1
25.00%
Américo Wang
22
24.18%
2
50.00%
Stephen Hemminger
3
3.30%
1
25.00%
Total
91
100.00%
4
100.00%


EXPORT_SYMBOL(tcf_generic_walker);



static struct tc_action *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
{
	struct tc_action *p = NULL;
	struct hlist_head *head;

	spin_lock_bh(&hinfo->lock);
	head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
	hlist_for_each_entry_rcu(p, head, tcfa_head)
		if (p->tcfa_index == index)
			break;
	spin_unlock_bh(&hinfo->lock);

	return p;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
55
67.90%
1
20.00%
Américo Wang
26
32.10%
4
80.00%
Total
81
100.00%
5
100.00%



u32 tcf_hash_new_index(struct tc_action_net *tn)
{
	struct tcf_hashinfo *hinfo = tn->hinfo;
	u32 val = hinfo->index;

	do {
		if (++val == 0)
			val = 1;
	} while (tcf_hash_lookup(val, hinfo));

	hinfo->index = val;
	return val;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
39
66.10%
1
25.00%
Américo Wang
17
28.81%
2
50.00%
Yang Yingliang
3
5.08%
1
25.00%
Total
59
100.00%
4
100.00%


EXPORT_SYMBOL(tcf_hash_new_index);



int tcf_hash_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
{
	struct tcf_hashinfo *hinfo = tn->hinfo;
	struct tc_action *p = tcf_hash_lookup(index, hinfo);

	if (p) {
		*a = p;
		return 1;
	}
	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
47
82.46%
1
25.00%
Américo Wang
10
17.54%
3
75.00%
Total
57
100.00%
4
100.00%


EXPORT_SYMBOL(tcf_hash_search);



bool tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
		    int bind)
{
	struct tcf_hashinfo *hinfo = tn->hinfo;
	struct tc_action *p = NULL;

	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
		if (bind)
			p->tcfa_bindcnt++;
		p->tcfa_refcnt++;
		*a = p;
		return true;
	}
	return false;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
59
71.95%
1
14.29%
Américo Wang
23
28.05%
6
85.71%
Total
82
100.00%
7
100.00%


EXPORT_SYMBOL(tcf_hash_check);



void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
{
	if (est)
		gen_kill_estimator(&a->tcfa_rate_est);
	call_rcu(&a->tcfa_rcu, free_tcf);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Américo Wang
32
86.49%
2
66.67%
Eric Dumazet
5
13.51%
1
33.33%
Total
37
100.00%
3
100.00%


EXPORT_SYMBOL(tcf_hash_cleanup);



int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
		    struct tc_action **a, const struct tc_action_ops *ops,
		    int bind, bool cpustats)
{
	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
	struct tcf_hashinfo *hinfo = tn->hinfo;
	int err = -ENOMEM;

	if (unlikely(!p))
		return -ENOMEM;
	p->tcfa_refcnt = 1;
	if (bind)
		p->tcfa_bindcnt = 1;

	if (cpustats) {
		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
		if (!p->cpu_bstats) {
err1:
			kfree(p);
			return err;
		}
		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
		if (!p->cpu_qstats) {
err2:
			free_percpu(p->cpu_bstats);
			goto err1;
		}
	}
	spin_lock_init(&p->tcfa_lock);
	INIT_HLIST_NODE(&p->tcfa_head);
	p->tcfa_index = index ? index : tcf_hash_new_index(tn);
	p->tcfa_tm.install = jiffies;
	p->tcfa_tm.lastuse = jiffies;
	p->tcfa_tm.firstuse = 0;
	if (est) {
		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
					&p->tcfa_rate_est,
					&p->tcfa_lock, NULL, est);
		if (err) {
			free_percpu(p->cpu_qstats);
			goto err2;
		}
	}

	p->hinfo = hinfo;
	p->ops = ops;
	INIT_LIST_HEAD(&p->list);
	*a = p;
	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
109
37.59%
1
6.67%
Eric Dumazet
88
30.34%
2
13.33%
Américo Wang
67
23.10%
6
40.00%
Stephen Hemminger
14
4.83%
1
6.67%
Jamal Hadi Salim
9
3.10%
2
13.33%
Patrick McHardy
2
0.69%
2
13.33%
John Fastabend
1
0.34%
1
6.67%
Total
290
100.00%
15
100.00%


EXPORT_SYMBOL(tcf_hash_create);



void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a)
{
	struct tcf_hashinfo *hinfo = tn->hinfo;
	unsigned int h = tcf_hash(a->tcfa_index, hinfo->hmask);

	spin_lock_bh(&hinfo->lock);
	hlist_add_head(&a->tcfa_head, &hinfo->htab[h]);
	spin_unlock_bh(&hinfo->lock);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David S. Miller
40
56.34%
1
14.29%
Américo Wang
30
42.25%
5
71.43%
Jamal Hadi Salim
1
1.41%
1
14.29%
Total
71
100.00%
7
100.00%


EXPORT_SYMBOL(tcf_hash_insert);



void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
			  struct tcf_hashinfo *hinfo)
{
	int i;

	for (i = 0; i < hinfo->hmask + 1; i++) {
		struct tc_action *p;
		struct hlist_node *n;

		hlist_for_each_entry_safe(p, n, &hinfo->htab[i], tcfa_head) {
			int ret;

			ret = __tcf_hash_release(p, false, true);
			if (ret == ACT_P_DELETED)
				module_put(ops->owner);
			else if (ret < 0)
				return;
		}
	}
	kfree(hinfo->htab);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Américo Wang
102
100.00%
4
100.00%
Total
102
100.00%
4
100.00%


EXPORT_SYMBOL(tcf_hashinfo_destroy);

static LIST_HEAD(act_base);
static DEFINE_RWLOCK(act_mod_lock);



int tcf_register_action(struct tc_action_ops *act,
			struct pernet_operations *ops)
{
	struct tc_action_ops *a;
	int ret;

	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
		return -EINVAL;

	/* We have to register pernet ops before making the action ops visible,
         * otherwise tcf_action_init_1() could get a partially initialized
         * netns.
         */
	ret = register_pernet_subsys(ops);
	if (ret)
		return ret;

	write_lock(&act_mod_lock);
	list_for_each_entry(a, &act_base, head) {
		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
			write_unlock(&act_mod_lock);
			unregister_pernet_subsys(ops);
			return -EEXIST;
		}
	}
	list_add_tail(&act->head, &act_base);
	write_unlock(&act_mod_lock);

	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
92
62.59%
4
50.00%
Américo Wang
55
37.41%
4
50.00%
Total
147
100.00%
8
100.00%


EXPORT_SYMBOL(tcf_register_action);



int tcf_unregister_action(struct tc_action_ops *act,
			  struct pernet_operations *ops)
{
	struct tc_action_ops *a;
	int err = -ENOENT;

	write_lock(&act_mod_lock);
	list_for_each_entry(a, &act_base, head) {
		if (a == act) {
			list_del(&act->head);
			err = 0;
			break;
		}
	}
	write_unlock(&act_mod_lock);
	if (!err)
		unregister_pernet_subsys(ops);
	return err;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
50
60.98%
1
20.00%
Américo Wang
29
35.37%
3
60.00%
Eric Dumazet
3
3.66%
1
20.00%
Total
82
100.00%
5
100.00%


EXPORT_SYMBOL(tcf_unregister_action);

/* lookup by name */


static struct tc_action_ops *tc_lookup_action_n(char *kind)
{
	struct tc_action_ops *a, *res = NULL;

	if (kind) {
		read_lock(&act_mod_lock);
		list_for_each_entry(a, &act_base, head) {
			if (strcmp(kind, a->kind) == 0) {
				if (try_module_get(a->owner))
					res = a;
				break;
			}
		}
		read_unlock(&act_mod_lock);
	}
	return res;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
66
80.49%
2
40.00%
Américo Wang
8
9.76%
1
20.00%
Eric Dumazet
7
8.54%
1
20.00%
Patrick McHardy
1
1.22%
1
20.00%
Total
82
100.00%
5
100.00%

/* lookup by nlattr */


static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
{
	struct tc_action_ops *a, *res = NULL;

	if (kind) {
		read_lock(&act_mod_lock);
		list_for_each_entry(a, &act_base, head) {
			if (nla_strcmp(kind, a->kind) == 0) {
				if (try_module_get(a->owner))
					res = a;
				break;
			}
		}
		read_unlock(&act_mod_lock);
	}
	return res;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
65
78.31%
2
33.33%
Américo Wang
8
9.64%
1
16.67%
Eric Dumazet
7
8.43%
1
16.67%
Patrick McHardy
3
3.61%
2
33.33%
Total
83
100.00%
6
100.00%



int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
		    int nr_actions, struct tcf_result *res)
{
	int ret = -1, i;

	if (skb_skip_tc_classify(skb))
		return TC_ACT_OK;

	for (i = 0; i < nr_actions; i++) {
		const struct tc_action *a = actions[i];

repeat:
		ret = a->ops->act(skb, a, res);
		if (ret == TC_ACT_REPEAT)
			goto repeat;	/* we need a ttl - JHS */
		if (ret != TC_ACT_PIPE)
			break;
	}
	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
61
58.10%
2
28.57%
Américo Wang
32
30.48%
2
28.57%
Willem de Bruijn
5
4.76%
1
14.29%
David S. Miller
5
4.76%
1
14.29%
Patrick McHardy
2
1.90%
1
14.29%
Total
105
100.00%
7
100.00%


EXPORT_SYMBOL(tcf_action_exec);



int tcf_action_destroy(struct list_head *actions, int bind)
{
	struct tc_action *a, *tmp;
	int ret = 0;

	list_for_each_entry_safe(a, tmp, actions, list) {
		ret = __tcf_hash_release(a, bind, true);
		if (ret == ACT_P_DELETED)
			module_put(a->ops->owner);
		else if (ret < 0)
			return ret;
	}
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Américo Wang
40
51.95%
2
33.33%
Jamal Hadi Salim
32
41.56%
2
33.33%
Daniel Borkmann
3
3.90%
1
16.67%
Patrick McHardy
2
2.60%
1
16.67%
Total
77
100.00%
6
100.00%


int

tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
	return a->ops->dump(skb, a, bind, ref);
}

Contributors
Person
Tokens
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Commits
CommitProp
Jamal Hadi Salim
37
100.00%
1
100.00%
Total
37
100.00%
1
100.00%


int

tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
	int err = -EINVAL;
	unsigned char *b = skb_tail_pointer(skb);
	struct nlattr *nest;

	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
		goto nla_put_failure;
	if (tcf_action_copy_stats(skb, a, 0))
		goto nla_put_failure;
	if (a->act_cookie) {
		if (nla_put(skb, TCA_ACT_COOKIE, a->act_cookie->len,
			    a->act_cookie->data))
			goto nla_put_failure;
	}

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;
	err = tcf_action_dump_old(skb, a, bind, ref);
	if (err > 0) {
		nla_nest_end(skb, nest);
		return err;
	}

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
135
80.36%
2
22.22%
Patrick McHardy
16
9.52%
2
22.22%
Arnaldo Carvalho de Melo
6
3.57%
2
22.22%
David S. Miller
5
2.98%
1
11.11%
Eric Dumazet
4
2.38%
1
11.11%
Thomas Graf
2
1.19%
1
11.11%
Total
168
100.00%
9
100.00%


EXPORT_SYMBOL(tcf_action_dump_1);



int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
		    int bind, int ref)
{
	struct tc_action *a;
	int err = -EINVAL;
	struct nlattr *nest;

	list_for_each_entry(a, actions, list) {
		nest = nla_nest_start(skb, a->order);
		if (nest == NULL)
			goto nla_put_failure;
		err = tcf_action_dump_1(skb, a, bind, ref);
		if (err < 0)
			goto errout;
		nla_nest_end(skb, nest);
	}

	return 0;

nla_put_failure:
	err = -EINVAL;
errout:
	nla_nest_cancel(skb, nest);
	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
76
64.41%
2
25.00%
Patrick McHardy
22
18.64%
3
37.50%
Américo Wang
10
8.47%
1
12.50%
Thomas Graf
8
6.78%
1
12.50%
Arnaldo Carvalho de Melo
2
1.69%
1
12.50%
Total
118
100.00%
8
100.00%



static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
{
	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
	if (!c)
		return NULL;

	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
	if (!c->data) {
		kfree(c);
		return NULL;
	}
	c->len = nla_len(tb[TCA_ACT_COOKIE]);

	return c;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jamal Hadi Salim
65
77.38%
1
33.33%
Wolfgang Bumiller
18
21.43%
1
33.33%
Wei Yongjun
1
1.19%
1
33.33%
Total
84
100.00%
3
100.00%



struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
				    struct nlattr *est, char *name, int ovr,
				    int bind)
{
	struct tc_action *a;
	struct tc_action_ops *a_o;
	struct tc_cookie *cookie = NULL;
	char act_name[IFNAMSIZ];
	struct nlattr *tb[TCA_ACT_MAX + 1];
	struct nlattr *kind;
	int err;

	if (name == NULL) {
		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
		if (err < 0)
			goto err_out;
		err = -EINVAL;
		kind = tb[TCA_ACT_KIND];
		if (kind == NULL)
			goto err_out;
		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
			goto err_out;
		if (tb[TCA_ACT_COOKIE]) {
			int cklen = nla_len(tb[TCA_ACT_COOKIE]);

			if (cklen > TC_COOKIE_MAX_SIZE)
				goto err_out;

			cookie = nla_memdup_cookie(tb);
			if (!cookie) {
				err = -ENOMEM;
				goto err_out;
			}
		}
	} else {
		err = -EINVAL;
		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
			goto err_out;
	}

	a_o = tc_lookup_action_n(act_name);
	if (a_o == NULL) {
#ifdef CONFIG_MODULES
		rtnl_unlock();
		request_module("act_%s", act_name);
		rtnl_lock();

		a_o = tc_lookup_action_n(act_name);

		/* We dropped the RTNL semaphore in order to
                 * perform the module load.  So, even if we
                 * succeeded in loading the module we have to
                 * tell the caller to replay the request.  We
                 * indicate this using -EAGAIN.
                 */
		if (a_o != NULL) {
			err = -EAGAIN;
			goto err_mod;
		}
#endif
		err = -ENOENT;
		goto err_out;
	}

	/* backward compatibility for policer */
	if (name == NULL)
		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind);
	else
		err = a_o->