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v3.15
 
  1/*
  2 * net/sched/mirred.c	packet mirroring and redirect actions
  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
  6 *		as published by the Free Software Foundation; either version
  7 *		2 of the License, or (at your option) any later version.
  8 *
  9 * Authors:	Jamal Hadi Salim (2002-4)
 10 *
 11 * TODO: Add ingress support (and socket redirect support)
 12 *
 13 */
 14
 15#include <linux/types.h>
 16#include <linux/kernel.h>
 17#include <linux/string.h>
 18#include <linux/errno.h>
 19#include <linux/skbuff.h>
 20#include <linux/rtnetlink.h>
 21#include <linux/module.h>
 22#include <linux/init.h>
 23#include <linux/gfp.h>
 
 24#include <net/net_namespace.h>
 25#include <net/netlink.h>
 26#include <net/pkt_sched.h>
 
 27#include <linux/tc_act/tc_mirred.h>
 28#include <net/tc_act/tc_mirred.h>
 29
 30#include <linux/if_arp.h>
 31
 32#define MIRRED_TAB_MASK     7
 33static LIST_HEAD(mirred_list);
 
 
 
 
 34
 35static void tcf_mirred_release(struct tc_action *a, int bind)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 36{
 37	struct tcf_mirred *m = to_mirred(a);
 
 
 
 38	list_del(&m->tcfm_list);
 39	if (m->tcfm_dev)
 40		dev_put(m->tcfm_dev);
 
 
 
 
 41}
 42
 43static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
 44	[TCA_MIRRED_PARMS]	= { .len = sizeof(struct tc_mirred) },
 45};
 46
 
 
 
 47static int tcf_mirred_init(struct net *net, struct nlattr *nla,
 48			   struct nlattr *est, struct tc_action *a, int ovr,
 49			   int bind)
 
 
 50{
 
 51	struct nlattr *tb[TCA_MIRRED_MAX + 1];
 
 
 52	struct tc_mirred *parm;
 53	struct tcf_mirred *m;
 54	struct net_device *dev;
 55	int ret, ok_push = 0;
 
 
 56
 57	if (nla == NULL)
 
 58		return -EINVAL;
 59	ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
 
 
 60	if (ret < 0)
 61		return ret;
 62	if (tb[TCA_MIRRED_PARMS] == NULL)
 
 63		return -EINVAL;
 
 64	parm = nla_data(tb[TCA_MIRRED_PARMS]);
 
 
 
 
 
 
 
 
 65	switch (parm->eaction) {
 66	case TCA_EGRESS_MIRROR:
 67	case TCA_EGRESS_REDIR:
 
 
 68		break;
 69	default:
 
 
 
 
 
 70		return -EINVAL;
 71	}
 72	if (parm->ifindex) {
 73		dev = __dev_get_by_index(net, parm->ifindex);
 74		if (dev == NULL)
 75			return -ENODEV;
 76		switch (dev->type) {
 77		case ARPHRD_TUNNEL:
 78		case ARPHRD_TUNNEL6:
 79		case ARPHRD_SIT:
 80		case ARPHRD_IPGRE:
 81		case ARPHRD_VOID:
 82		case ARPHRD_NONE:
 83			ok_push = 0;
 84			break;
 85		default:
 86			ok_push = 1;
 87			break;
 88		}
 89	} else {
 90		dev = NULL;
 91	}
 92
 93	if (!tcf_hash_check(parm->index, a, bind)) {
 94		if (dev == NULL)
 
 
 95			return -EINVAL;
 96		ret = tcf_hash_create(parm->index, est, a, sizeof(*m), bind);
 97		if (ret)
 
 
 
 98			return ret;
 99		ret = ACT_P_CREATED;
100	} else {
101		if (!ovr) {
102			tcf_hash_release(a, bind);
103			return -EEXIST;
104		}
 
 
 
 
105	}
106	m = to_mirred(a);
 
 
 
 
 
 
 
107
108	spin_lock_bh(&m->tcf_lock);
109	m->tcf_action = parm->action;
110	m->tcfm_eaction = parm->eaction;
111	if (dev != NULL) {
112		m->tcfm_ifindex = parm->ifindex;
113		if (ret != ACT_P_CREATED)
114			dev_put(m->tcfm_dev);
115		dev_hold(dev);
116		m->tcfm_dev = dev;
117		m->tcfm_ok_push = ok_push;
 
 
 
 
 
118	}
 
 
119	spin_unlock_bh(&m->tcf_lock);
 
 
 
120	if (ret == ACT_P_CREATED) {
 
121		list_add(&m->tcfm_list, &mirred_list);
122		tcf_hash_insert(a);
 
 
123	}
124
125	return ret;
 
 
 
 
 
 
126}
127
128static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
129		      struct tcf_result *res)
130{
131	struct tcf_mirred *m = a->priv;
 
 
132	struct net_device *dev;
133	struct sk_buff *skb2;
134	u32 at;
135	int retval, err = 1;
136
137	spin_lock(&m->tcf_lock);
138	m->tcf_tm.lastuse = jiffies;
139	bstats_update(&m->tcf_bstats, skb);
140
141	dev = m->tcfm_dev;
142	if (!dev) {
143		printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
144		goto out;
145	}
146
147	if (!(dev->flags & IFF_UP)) {
148		net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
149				       dev->name);
150		goto out;
151	}
152
153	at = G_TC_AT(skb->tc_verd);
154	skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
155	if (skb2 == NULL)
156		goto out;
157
158	if (!(at & AT_EGRESS)) {
159		if (m->tcfm_ok_push)
160			skb_push(skb2, skb2->dev->hard_header_len);
 
 
 
161	}
162
163	/* mirror is always swallowed */
164	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
165		skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
 
 
 
 
 
 
 
 
 
 
 
 
166
167	skb2->skb_iif = skb->dev->ifindex;
168	skb2->dev = dev;
169	err = dev_queue_xmit(skb2);
170
171out:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
172	if (err) {
173		m->tcf_qstats.overlimits++;
174		if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
 
175			retval = TC_ACT_SHOT;
176		else
177			retval = m->tcf_action;
178	} else
179		retval = m->tcf_action;
180	spin_unlock(&m->tcf_lock);
181
182	return retval;
183}
184
185static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
186{
187	unsigned char *b = skb_tail_pointer(skb);
188	struct tcf_mirred *m = a->priv;
189	struct tc_mirred opt = {
190		.index   = m->tcf_index,
191		.action  = m->tcf_action,
192		.refcnt  = m->tcf_refcnt - ref,
193		.bindcnt = m->tcf_bindcnt - bind,
194		.eaction = m->tcfm_eaction,
195		.ifindex = m->tcfm_ifindex,
196	};
 
197	struct tcf_t t;
198
 
 
 
 
 
 
 
199	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
200		goto nla_put_failure;
201	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
202	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
203	t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
204	if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
205		goto nla_put_failure;
 
 
206	return skb->len;
207
208nla_put_failure:
 
209	nlmsg_trim(skb, b);
210	return -1;
211}
212
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
213static int mirred_device_event(struct notifier_block *unused,
214			       unsigned long event, void *ptr)
215{
216	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
217	struct tcf_mirred *m;
218
219	if (event == NETDEV_UNREGISTER)
 
 
220		list_for_each_entry(m, &mirred_list, tcfm_list) {
221			if (m->tcfm_dev == dev) {
 
222				dev_put(dev);
223				m->tcfm_dev = NULL;
 
 
 
224			}
 
225		}
 
 
226
227	return NOTIFY_DONE;
228}
229
230static struct notifier_block mirred_device_notifier = {
231	.notifier_call = mirred_device_event,
232};
233
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
234static struct tc_action_ops act_mirred_ops = {
235	.kind		=	"mirred",
236	.type		=	TCA_ACT_MIRRED,
237	.owner		=	THIS_MODULE,
238	.act		=	tcf_mirred,
 
239	.dump		=	tcf_mirred_dump,
240	.cleanup	=	tcf_mirred_release,
241	.init		=	tcf_mirred_init,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
242};
243
244MODULE_AUTHOR("Jamal Hadi Salim(2002)");
245MODULE_DESCRIPTION("Device Mirror/redirect actions");
246MODULE_LICENSE("GPL");
247
248static int __init mirred_init_module(void)
249{
250	int err = register_netdevice_notifier(&mirred_device_notifier);
251	if (err)
252		return err;
253
254	pr_info("Mirror/redirect action on\n");
255	return tcf_register_action(&act_mirred_ops, MIRRED_TAB_MASK);
 
 
 
 
256}
257
258static void __exit mirred_cleanup_module(void)
259{
260	tcf_unregister_action(&act_mirred_ops);
261	unregister_netdevice_notifier(&mirred_device_notifier);
262}
263
264module_init(mirred_init_module);
265module_exit(mirred_cleanup_module);
v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * net/sched/act_mirred.c	packet mirroring and redirect actions
 
 
 
 
 
  4 *
  5 * Authors:	Jamal Hadi Salim (2002-4)
  6 *
  7 * TODO: Add ingress support (and socket redirect support)
 
  8 */
  9
 10#include <linux/types.h>
 11#include <linux/kernel.h>
 12#include <linux/string.h>
 13#include <linux/errno.h>
 14#include <linux/skbuff.h>
 15#include <linux/rtnetlink.h>
 16#include <linux/module.h>
 17#include <linux/init.h>
 18#include <linux/gfp.h>
 19#include <linux/if_arp.h>
 20#include <net/net_namespace.h>
 21#include <net/netlink.h>
 22#include <net/pkt_sched.h>
 23#include <net/pkt_cls.h>
 24#include <linux/tc_act/tc_mirred.h>
 25#include <net/tc_act/tc_mirred.h>
 26
 
 
 
 27static LIST_HEAD(mirred_list);
 28static DEFINE_SPINLOCK(mirred_list_lock);
 29
 30#define MIRRED_RECURSION_LIMIT    4
 31static DEFINE_PER_CPU(unsigned int, mirred_rec_level);
 32
 33static bool tcf_mirred_is_act_redirect(int action)
 34{
 35	return action == TCA_EGRESS_REDIR || action == TCA_INGRESS_REDIR;
 36}
 37
 38static bool tcf_mirred_act_wants_ingress(int action)
 39{
 40	switch (action) {
 41	case TCA_EGRESS_REDIR:
 42	case TCA_EGRESS_MIRROR:
 43		return false;
 44	case TCA_INGRESS_REDIR:
 45	case TCA_INGRESS_MIRROR:
 46		return true;
 47	default:
 48		BUG();
 49	}
 50}
 51
 52static bool tcf_mirred_can_reinsert(int action)
 53{
 54	switch (action) {
 55	case TC_ACT_SHOT:
 56	case TC_ACT_STOLEN:
 57	case TC_ACT_QUEUED:
 58	case TC_ACT_TRAP:
 59		return true;
 60	}
 61	return false;
 62}
 63
 64static struct net_device *tcf_mirred_dev_dereference(struct tcf_mirred *m)
 65{
 66	return rcu_dereference_protected(m->tcfm_dev,
 67					 lockdep_is_held(&m->tcf_lock));
 68}
 69
 70static void tcf_mirred_release(struct tc_action *a)
 71{
 72	struct tcf_mirred *m = to_mirred(a);
 73	struct net_device *dev;
 74
 75	spin_lock(&mirred_list_lock);
 76	list_del(&m->tcfm_list);
 77	spin_unlock(&mirred_list_lock);
 78
 79	/* last reference to action, no need to lock */
 80	dev = rcu_dereference_protected(m->tcfm_dev, 1);
 81	if (dev)
 82		dev_put(dev);
 83}
 84
 85static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
 86	[TCA_MIRRED_PARMS]	= { .len = sizeof(struct tc_mirred) },
 87};
 88
 89static unsigned int mirred_net_id;
 90static struct tc_action_ops act_mirred_ops;
 91
 92static int tcf_mirred_init(struct net *net, struct nlattr *nla,
 93			   struct nlattr *est, struct tc_action **a,
 94			   int ovr, int bind, bool rtnl_held,
 95			   struct tcf_proto *tp,
 96			   struct netlink_ext_ack *extack)
 97{
 98	struct tc_action_net *tn = net_generic(net, mirred_net_id);
 99	struct nlattr *tb[TCA_MIRRED_MAX + 1];
100	struct tcf_chain *goto_ch = NULL;
101	bool mac_header_xmit = false;
102	struct tc_mirred *parm;
103	struct tcf_mirred *m;
104	struct net_device *dev;
105	bool exists = false;
106	int ret, err;
107	u32 index;
108
109	if (!nla) {
110		NL_SET_ERR_MSG_MOD(extack, "Mirred requires attributes to be passed");
111		return -EINVAL;
112	}
113	ret = nla_parse_nested_deprecated(tb, TCA_MIRRED_MAX, nla,
114					  mirred_policy, extack);
115	if (ret < 0)
116		return ret;
117	if (!tb[TCA_MIRRED_PARMS]) {
118		NL_SET_ERR_MSG_MOD(extack, "Missing required mirred parameters");
119		return -EINVAL;
120	}
121	parm = nla_data(tb[TCA_MIRRED_PARMS]);
122	index = parm->index;
123	err = tcf_idr_check_alloc(tn, &index, a, bind);
124	if (err < 0)
125		return err;
126	exists = err;
127	if (exists && bind)
128		return 0;
129
130	switch (parm->eaction) {
131	case TCA_EGRESS_MIRROR:
132	case TCA_EGRESS_REDIR:
133	case TCA_INGRESS_REDIR:
134	case TCA_INGRESS_MIRROR:
135		break;
136	default:
137		if (exists)
138			tcf_idr_release(*a, bind);
139		else
140			tcf_idr_cleanup(tn, index);
141		NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option");
142		return -EINVAL;
143	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
144
145	if (!exists) {
146		if (!parm->ifindex) {
147			tcf_idr_cleanup(tn, index);
148			NL_SET_ERR_MSG_MOD(extack, "Specified device does not exist");
149			return -EINVAL;
150		}
151		ret = tcf_idr_create(tn, index, est, a,
152				     &act_mirred_ops, bind, true);
153		if (ret) {
154			tcf_idr_cleanup(tn, index);
155			return ret;
 
 
 
 
 
156		}
157		ret = ACT_P_CREATED;
158	} else if (!ovr) {
159		tcf_idr_release(*a, bind);
160		return -EEXIST;
161	}
162
163	m = to_mirred(*a);
164	if (ret == ACT_P_CREATED)
165		INIT_LIST_HEAD(&m->tcfm_list);
166
167	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
168	if (err < 0)
169		goto release_idr;
170
171	spin_lock_bh(&m->tcf_lock);
172
173	if (parm->ifindex) {
174		dev = dev_get_by_index(net, parm->ifindex);
175		if (!dev) {
176			spin_unlock_bh(&m->tcf_lock);
177			err = -ENODEV;
178			goto put_chain;
179		}
180		mac_header_xmit = dev_is_mac_header_xmit(dev);
181		rcu_swap_protected(m->tcfm_dev, dev,
182				   lockdep_is_held(&m->tcf_lock));
183		if (dev)
184			dev_put(dev);
185		m->tcfm_mac_header_xmit = mac_header_xmit;
186	}
187	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
188	m->tcfm_eaction = parm->eaction;
189	spin_unlock_bh(&m->tcf_lock);
190	if (goto_ch)
191		tcf_chain_put_by_act(goto_ch);
192
193	if (ret == ACT_P_CREATED) {
194		spin_lock(&mirred_list_lock);
195		list_add(&m->tcfm_list, &mirred_list);
196		spin_unlock(&mirred_list_lock);
197
198		tcf_idr_insert(tn, *a);
199	}
200
201	return ret;
202put_chain:
203	if (goto_ch)
204		tcf_chain_put_by_act(goto_ch);
205release_idr:
206	tcf_idr_release(*a, bind);
207	return err;
208}
209
210static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
211			  struct tcf_result *res)
212{
213	struct tcf_mirred *m = to_mirred(a);
214	struct sk_buff *skb2 = skb;
215	bool m_mac_header_xmit;
216	struct net_device *dev;
217	unsigned int rec_level;
218	int retval, err = 0;
219	bool use_reinsert;
220	bool want_ingress;
221	bool is_redirect;
222	int m_eaction;
223	int mac_len;
224
225	rec_level = __this_cpu_inc_return(mirred_rec_level);
226	if (unlikely(rec_level > MIRRED_RECURSION_LIMIT)) {
227		net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n",
228				     netdev_name(skb->dev));
229		__this_cpu_dec(mirred_rec_level);
230		return TC_ACT_SHOT;
231	}
232
233	tcf_lastuse_update(&m->tcf_tm);
234	bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
235
236	m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit);
237	m_eaction = READ_ONCE(m->tcfm_eaction);
238	retval = READ_ONCE(m->tcf_action);
239	dev = rcu_dereference_bh(m->tcfm_dev);
240	if (unlikely(!dev)) {
241		pr_notice_once("tc mirred: target device is gone\n");
242		goto out;
243	}
244
245	if (unlikely(!(dev->flags & IFF_UP))) {
246		net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
247				       dev->name);
248		goto out;
249	}
250
251	/* we could easily avoid the clone only if called by ingress and clsact;
252	 * since we can't easily detect the clsact caller, skip clone only for
253	 * ingress - that covers the TC S/W datapath.
254	 */
255	is_redirect = tcf_mirred_is_act_redirect(m_eaction);
256	use_reinsert = skb_at_tc_ingress(skb) && is_redirect &&
257		       tcf_mirred_can_reinsert(retval);
258	if (!use_reinsert) {
259		skb2 = skb_clone(skb, GFP_ATOMIC);
260		if (!skb2)
261			goto out;
262	}
263
264	/* If action's target direction differs than filter's direction,
265	 * and devices expect a mac header on xmit, then mac push/pull is
266	 * needed.
267	 */
268	want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
269	if (skb_at_tc_ingress(skb) != want_ingress && m_mac_header_xmit) {
270		if (!skb_at_tc_ingress(skb)) {
271			/* caught at egress, act ingress: pull mac */
272			mac_len = skb_network_header(skb) - skb_mac_header(skb);
273			skb_pull_rcsum(skb2, mac_len);
274		} else {
275			/* caught at ingress, act egress: push mac */
276			skb_push_rcsum(skb2, skb->mac_len);
277		}
278	}
279
280	skb2->skb_iif = skb->dev->ifindex;
281	skb2->dev = dev;
 
282
283	/* mirror is always swallowed */
284	if (is_redirect) {
285		skb2->tc_redirected = 1;
286		skb2->tc_from_ingress = skb2->tc_at_ingress;
287		if (skb2->tc_from_ingress)
288			skb2->tstamp = 0;
289		/* let's the caller reinsert the packet, if possible */
290		if (use_reinsert) {
291			res->ingress = want_ingress;
292			res->qstats = this_cpu_ptr(m->common.cpu_qstats);
293			skb_tc_reinsert(skb, res);
294			__this_cpu_dec(mirred_rec_level);
295			return TC_ACT_CONSUMED;
296		}
297	}
298
299	if (!want_ingress)
300		err = dev_queue_xmit(skb2);
301	else
302		err = netif_receive_skb(skb2);
303
304	if (err) {
305out:
306		qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
307		if (tcf_mirred_is_act_redirect(m_eaction))
308			retval = TC_ACT_SHOT;
309	}
310	__this_cpu_dec(mirred_rec_level);
 
 
 
311
312	return retval;
313}
314
315static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
316			     u64 lastuse, bool hw)
317{
318	struct tcf_mirred *m = to_mirred(a);
319	struct tcf_t *tm = &m->tcf_tm;
320
321	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
322	if (hw)
323		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
324				   bytes, packets);
325	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
326}
327
328static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
329			   int ref)
330{
331	unsigned char *b = skb_tail_pointer(skb);
332	struct tcf_mirred *m = to_mirred(a);
333	struct tc_mirred opt = {
334		.index   = m->tcf_index,
335		.refcnt  = refcount_read(&m->tcf_refcnt) - ref,
336		.bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
 
 
 
337	};
338	struct net_device *dev;
339	struct tcf_t t;
340
341	spin_lock_bh(&m->tcf_lock);
342	opt.action = m->tcf_action;
343	opt.eaction = m->tcfm_eaction;
344	dev = tcf_mirred_dev_dereference(m);
345	if (dev)
346		opt.ifindex = dev->ifindex;
347
348	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
349		goto nla_put_failure;
350
351	tcf_tm_dump(&t, &m->tcf_tm);
352	if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
 
353		goto nla_put_failure;
354	spin_unlock_bh(&m->tcf_lock);
355
356	return skb->len;
357
358nla_put_failure:
359	spin_unlock_bh(&m->tcf_lock);
360	nlmsg_trim(skb, b);
361	return -1;
362}
363
364static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
365			     struct netlink_callback *cb, int type,
366			     const struct tc_action_ops *ops,
367			     struct netlink_ext_ack *extack)
368{
369	struct tc_action_net *tn = net_generic(net, mirred_net_id);
370
371	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
372}
373
374static int tcf_mirred_search(struct net *net, struct tc_action **a, u32 index)
375{
376	struct tc_action_net *tn = net_generic(net, mirred_net_id);
377
378	return tcf_idr_search(tn, a, index);
379}
380
381static int mirred_device_event(struct notifier_block *unused,
382			       unsigned long event, void *ptr)
383{
384	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
385	struct tcf_mirred *m;
386
387	ASSERT_RTNL();
388	if (event == NETDEV_UNREGISTER) {
389		spin_lock(&mirred_list_lock);
390		list_for_each_entry(m, &mirred_list, tcfm_list) {
391			spin_lock_bh(&m->tcf_lock);
392			if (tcf_mirred_dev_dereference(m) == dev) {
393				dev_put(dev);
394				/* Note : no rcu grace period necessary, as
395				 * net_device are already rcu protected.
396				 */
397				RCU_INIT_POINTER(m->tcfm_dev, NULL);
398			}
399			spin_unlock_bh(&m->tcf_lock);
400		}
401		spin_unlock(&mirred_list_lock);
402	}
403
404	return NOTIFY_DONE;
405}
406
407static struct notifier_block mirred_device_notifier = {
408	.notifier_call = mirred_device_event,
409};
410
411static void tcf_mirred_dev_put(void *priv)
412{
413	struct net_device *dev = priv;
414
415	dev_put(dev);
416}
417
418static struct net_device *
419tcf_mirred_get_dev(const struct tc_action *a,
420		   tc_action_priv_destructor *destructor)
421{
422	struct tcf_mirred *m = to_mirred(a);
423	struct net_device *dev;
424
425	rcu_read_lock();
426	dev = rcu_dereference(m->tcfm_dev);
427	if (dev) {
428		dev_hold(dev);
429		*destructor = tcf_mirred_dev_put;
430	}
431	rcu_read_unlock();
432
433	return dev;
434}
435
436static size_t tcf_mirred_get_fill_size(const struct tc_action *act)
437{
438	return nla_total_size(sizeof(struct tc_mirred));
439}
440
441static struct tc_action_ops act_mirred_ops = {
442	.kind		=	"mirred",
443	.id		=	TCA_ID_MIRRED,
444	.owner		=	THIS_MODULE,
445	.act		=	tcf_mirred_act,
446	.stats_update	=	tcf_stats_update,
447	.dump		=	tcf_mirred_dump,
448	.cleanup	=	tcf_mirred_release,
449	.init		=	tcf_mirred_init,
450	.walk		=	tcf_mirred_walker,
451	.lookup		=	tcf_mirred_search,
452	.get_fill_size	=	tcf_mirred_get_fill_size,
453	.size		=	sizeof(struct tcf_mirred),
454	.get_dev	=	tcf_mirred_get_dev,
455};
456
457static __net_init int mirred_init_net(struct net *net)
458{
459	struct tc_action_net *tn = net_generic(net, mirred_net_id);
460
461	return tc_action_net_init(net, tn, &act_mirred_ops);
462}
463
464static void __net_exit mirred_exit_net(struct list_head *net_list)
465{
466	tc_action_net_exit(net_list, mirred_net_id);
467}
468
469static struct pernet_operations mirred_net_ops = {
470	.init = mirred_init_net,
471	.exit_batch = mirred_exit_net,
472	.id   = &mirred_net_id,
473	.size = sizeof(struct tc_action_net),
474};
475
476MODULE_AUTHOR("Jamal Hadi Salim(2002)");
477MODULE_DESCRIPTION("Device Mirror/redirect actions");
478MODULE_LICENSE("GPL");
479
480static int __init mirred_init_module(void)
481{
482	int err = register_netdevice_notifier(&mirred_device_notifier);
483	if (err)
484		return err;
485
486	pr_info("Mirror/redirect action on\n");
487	err = tcf_register_action(&act_mirred_ops, &mirred_net_ops);
488	if (err)
489		unregister_netdevice_notifier(&mirred_device_notifier);
490
491	return err;
492}
493
494static void __exit mirred_cleanup_module(void)
495{
496	tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
497	unregister_netdevice_notifier(&mirred_device_notifier);
498}
499
500module_init(mirred_init_module);
501module_exit(mirred_cleanup_module);