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v5.9
  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			   u32 flags, 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_from_flags(tn, index, est, a,
152						&act_mirred_ops, bind, flags);
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		dev = rcu_replace_pointer(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
199	return ret;
200put_chain:
201	if (goto_ch)
202		tcf_chain_put_by_act(goto_ch);
203release_idr:
204	tcf_idr_release(*a, bind);
205	return err;
206}
207
208static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
209			  struct tcf_result *res)
210{
211	struct tcf_mirred *m = to_mirred(a);
212	struct sk_buff *skb2 = skb;
213	bool m_mac_header_xmit;
214	struct net_device *dev;
215	unsigned int rec_level;
216	int retval, err = 0;
217	bool use_reinsert;
218	bool want_ingress;
219	bool is_redirect;
220	bool expects_nh;
221	int m_eaction;
222	int mac_len;
223	bool at_nh;
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	tcf_action_update_bstats(&m->common, 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	want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
265
266	expects_nh = want_ingress || !m_mac_header_xmit;
267	at_nh = skb->data == skb_network_header(skb);
268	if (at_nh != expects_nh) {
269		mac_len = skb_at_tc_ingress(skb) ? skb->mac_len :
270			  skb_network_header(skb) - skb_mac_header(skb);
271		if (expects_nh) {
272			/* target device/action expect data at nh */
273			skb_pull_rcsum(skb2, mac_len);
274		} else {
275			/* target device/action expect data at mac */
276			skb_push_rcsum(skb2, 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		skb_set_redirected(skb2, skb2->tc_at_ingress);
286
287		/* let's the caller reinsert the packet, if possible */
288		if (use_reinsert) {
289			res->ingress = want_ingress;
290			if (skb_tc_reinsert(skb, res))
291				tcf_action_inc_overlimit_qstats(&m->common);
292			__this_cpu_dec(mirred_rec_level);
293			return TC_ACT_CONSUMED;
294		}
295	}
296
297	if (!want_ingress)
298		err = dev_queue_xmit(skb2);
299	else
300		err = netif_receive_skb(skb2);
301
302	if (err) {
303out:
304		tcf_action_inc_overlimit_qstats(&m->common);
305		if (tcf_mirred_is_act_redirect(m_eaction))
306			retval = TC_ACT_SHOT;
 
 
 
 
 
307	}
308	__this_cpu_dec(mirred_rec_level);
309
310	return retval;
311}
312
313static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets,
314			     u64 drops, u64 lastuse, bool hw)
315{
316	struct tcf_mirred *m = to_mirred(a);
317	struct tcf_t *tm = &m->tcf_tm;
318
319	tcf_action_update_stats(a, bytes, packets, drops, hw);
320	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
321}
322
323static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
324			   int ref)
325{
326	unsigned char *b = skb_tail_pointer(skb);
327	struct tcf_mirred *m = to_mirred(a);
328	struct tc_mirred opt = {
329		.index   = m->tcf_index,
330		.refcnt  = refcount_read(&m->tcf_refcnt) - ref,
331		.bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
 
 
 
332	};
333	struct net_device *dev;
334	struct tcf_t t;
335
336	spin_lock_bh(&m->tcf_lock);
337	opt.action = m->tcf_action;
338	opt.eaction = m->tcfm_eaction;
339	dev = tcf_mirred_dev_dereference(m);
340	if (dev)
341		opt.ifindex = dev->ifindex;
342
343	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
344		goto nla_put_failure;
345
346	tcf_tm_dump(&t, &m->tcf_tm);
347	if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
 
348		goto nla_put_failure;
349	spin_unlock_bh(&m->tcf_lock);
350
351	return skb->len;
352
353nla_put_failure:
354	spin_unlock_bh(&m->tcf_lock);
355	nlmsg_trim(skb, b);
356	return -1;
357}
358
359static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
360			     struct netlink_callback *cb, int type,
361			     const struct tc_action_ops *ops,
362			     struct netlink_ext_ack *extack)
363{
364	struct tc_action_net *tn = net_generic(net, mirred_net_id);
365
366	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
367}
368
369static int tcf_mirred_search(struct net *net, struct tc_action **a, u32 index)
370{
371	struct tc_action_net *tn = net_generic(net, mirred_net_id);
372
373	return tcf_idr_search(tn, a, index);
374}
375
376static int mirred_device_event(struct notifier_block *unused,
377			       unsigned long event, void *ptr)
378{
379	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
380	struct tcf_mirred *m;
381
382	ASSERT_RTNL();
383	if (event == NETDEV_UNREGISTER) {
384		spin_lock(&mirred_list_lock);
385		list_for_each_entry(m, &mirred_list, tcfm_list) {
386			spin_lock_bh(&m->tcf_lock);
387			if (tcf_mirred_dev_dereference(m) == dev) {
388				dev_put(dev);
389				/* Note : no rcu grace period necessary, as
390				 * net_device are already rcu protected.
391				 */
392				RCU_INIT_POINTER(m->tcfm_dev, NULL);
393			}
394			spin_unlock_bh(&m->tcf_lock);
395		}
396		spin_unlock(&mirred_list_lock);
397	}
398
399	return NOTIFY_DONE;
400}
401
402static struct notifier_block mirred_device_notifier = {
403	.notifier_call = mirred_device_event,
404};
405
406static void tcf_mirred_dev_put(void *priv)
407{
408	struct net_device *dev = priv;
409
410	dev_put(dev);
411}
412
413static struct net_device *
414tcf_mirred_get_dev(const struct tc_action *a,
415		   tc_action_priv_destructor *destructor)
416{
417	struct tcf_mirred *m = to_mirred(a);
418	struct net_device *dev;
419
420	rcu_read_lock();
421	dev = rcu_dereference(m->tcfm_dev);
422	if (dev) {
423		dev_hold(dev);
424		*destructor = tcf_mirred_dev_put;
425	}
426	rcu_read_unlock();
427
428	return dev;
429}
430
431static size_t tcf_mirred_get_fill_size(const struct tc_action *act)
432{
433	return nla_total_size(sizeof(struct tc_mirred));
434}
435
436static struct tc_action_ops act_mirred_ops = {
437	.kind		=	"mirred",
438	.id		=	TCA_ID_MIRRED,
 
 
439	.owner		=	THIS_MODULE,
440	.act		=	tcf_mirred_act,
441	.stats_update	=	tcf_stats_update,
442	.dump		=	tcf_mirred_dump,
443	.cleanup	=	tcf_mirred_release,
 
444	.init		=	tcf_mirred_init,
445	.walk		=	tcf_mirred_walker,
446	.lookup		=	tcf_mirred_search,
447	.get_fill_size	=	tcf_mirred_get_fill_size,
448	.size		=	sizeof(struct tcf_mirred),
449	.get_dev	=	tcf_mirred_get_dev,
450};
451
452static __net_init int mirred_init_net(struct net *net)
453{
454	struct tc_action_net *tn = net_generic(net, mirred_net_id);
455
456	return tc_action_net_init(net, tn, &act_mirred_ops);
457}
458
459static void __net_exit mirred_exit_net(struct list_head *net_list)
460{
461	tc_action_net_exit(net_list, mirred_net_id);
462}
463
464static struct pernet_operations mirred_net_ops = {
465	.init = mirred_init_net,
466	.exit_batch = mirred_exit_net,
467	.id   = &mirred_net_id,
468	.size = sizeof(struct tc_action_net),
469};
470
471MODULE_AUTHOR("Jamal Hadi Salim(2002)");
472MODULE_DESCRIPTION("Device Mirror/redirect actions");
473MODULE_LICENSE("GPL");
474
475static int __init mirred_init_module(void)
476{
477	int err = register_netdevice_notifier(&mirred_device_notifier);
478	if (err)
479		return err;
480
481	pr_info("Mirror/redirect action on\n");
482	err = tcf_register_action(&act_mirred_ops, &mirred_net_ops);
483	if (err)
484		unregister_netdevice_notifier(&mirred_device_notifier);
485
486	return err;
487}
488
489static void __exit mirred_cleanup_module(void)
490{
491	tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
492	unregister_netdevice_notifier(&mirred_device_notifier);
 
493}
494
495module_init(mirred_init_module);
496module_exit(mirred_cleanup_module);
v3.5.6
 
  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 struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
 34static u32 mirred_idx_gen;
 35static DEFINE_RWLOCK(mirred_lock);
 36static LIST_HEAD(mirred_list);
 37
 38static struct tcf_hashinfo mirred_hash_info = {
 39	.htab	=	tcf_mirred_ht,
 40	.hmask	=	MIRRED_TAB_MASK,
 41	.lock	=	&mirred_lock,
 42};
 
 
 
 
 
 
 
 
 43
 44static int tcf_mirred_release(struct tcf_mirred *m, int bind)
 45{
 46	if (m) {
 47		if (bind)
 48			m->tcf_bindcnt--;
 49		m->tcf_refcnt--;
 50		if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
 51			list_del(&m->tcfm_list);
 52			if (m->tcfm_dev)
 53				dev_put(m->tcfm_dev);
 54			tcf_hash_destroy(&m->common, &mirred_hash_info);
 55			return 1;
 56		}
 57	}
 58	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 59}
 60
 61static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
 62	[TCA_MIRRED_PARMS]	= { .len = sizeof(struct tc_mirred) },
 63};
 64
 65static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
 66			   struct tc_action *a, int ovr, int bind)
 
 
 
 
 
 
 67{
 
 68	struct nlattr *tb[TCA_MIRRED_MAX + 1];
 
 
 69	struct tc_mirred *parm;
 70	struct tcf_mirred *m;
 71	struct tcf_common *pc;
 72	struct net_device *dev;
 73	int ret, ok_push = 0;
 
 
 74
 75	if (nla == NULL)
 
 76		return -EINVAL;
 77	ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
 
 
 78	if (ret < 0)
 79		return ret;
 80	if (tb[TCA_MIRRED_PARMS] == NULL)
 
 81		return -EINVAL;
 
 82	parm = nla_data(tb[TCA_MIRRED_PARMS]);
 
 
 
 
 
 
 
 
 83	switch (parm->eaction) {
 84	case TCA_EGRESS_MIRROR:
 85	case TCA_EGRESS_REDIR:
 
 
 86		break;
 87	default:
 
 
 
 
 
 88		return -EINVAL;
 89	}
 90	if (parm->ifindex) {
 91		dev = __dev_get_by_index(&init_net, parm->ifindex);
 92		if (dev == NULL)
 93			return -ENODEV;
 94		switch (dev->type) {
 95		case ARPHRD_TUNNEL:
 96		case ARPHRD_TUNNEL6:
 97		case ARPHRD_SIT:
 98		case ARPHRD_IPGRE:
 99		case ARPHRD_VOID:
100		case ARPHRD_NONE:
101			ok_push = 0;
102			break;
103		default:
104			ok_push = 1;
105			break;
106		}
107	} else {
108		dev = NULL;
109	}
110
111	pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
112	if (!pc) {
113		if (dev == NULL)
 
114			return -EINVAL;
115		pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
116				     &mirred_idx_gen, &mirred_hash_info);
117		if (IS_ERR(pc))
118			return PTR_ERR(pc);
 
 
 
119		ret = ACT_P_CREATED;
120	} else {
121		if (!ovr) {
122			tcf_mirred_release(to_mirred(pc), bind);
123			return -EEXIST;
124		}
125	}
126	m = to_mirred(pc);
 
 
 
 
 
 
 
127
128	spin_lock_bh(&m->tcf_lock);
129	m->tcf_action = parm->action;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
130	m->tcfm_eaction = parm->eaction;
131	if (dev != NULL) {
132		m->tcfm_ifindex = parm->ifindex;
133		if (ret != ACT_P_CREATED)
134			dev_put(m->tcfm_dev);
135		dev_hold(dev);
136		m->tcfm_dev = dev;
137		m->tcfm_ok_push = ok_push;
138	}
139	spin_unlock_bh(&m->tcf_lock);
 
 
 
140	if (ret == ACT_P_CREATED) {
 
141		list_add(&m->tcfm_list, &mirred_list);
142		tcf_hash_insert(pc, &mirred_hash_info);
143	}
144
145	return ret;
 
 
 
 
 
 
146}
147
148static int tcf_mirred_cleanup(struct tc_action *a, int bind)
 
149{
150	struct tcf_mirred *m = a->priv;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
151
152	if (m)
153		return tcf_mirred_release(m, bind);
154	return 0;
155}
156
157static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
158		      struct tcf_result *res)
159{
160	struct tcf_mirred *m = a->priv;
161	struct net_device *dev;
162	struct sk_buff *skb2;
163	u32 at;
164	int retval, err = 1;
165
166	spin_lock(&m->tcf_lock);
167	m->tcf_tm.lastuse = jiffies;
168	bstats_update(&m->tcf_bstats, skb);
169
170	dev = m->tcfm_dev;
171	if (!dev) {
172		printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
173		goto out;
174	}
175
176	if (!(dev->flags & IFF_UP)) {
177		net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
178				       dev->name);
179		goto out;
180	}
181
182	at = G_TC_AT(skb->tc_verd);
183	skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
184	if (skb2 == NULL)
185		goto out;
 
 
 
 
 
 
 
 
 
 
186
187	if (!(at & AT_EGRESS)) {
188		if (m->tcfm_ok_push)
189			skb_push(skb2, skb2->dev->hard_header_len);
 
 
 
 
 
 
 
 
 
190	}
191
 
 
 
192	/* mirror is always swallowed */
193	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
194		skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
195
196	skb2->skb_iif = skb->dev->ifindex;
197	skb2->dev = dev;
198	err = dev_queue_xmit(skb2);
 
 
 
 
 
 
 
 
 
 
 
199
 
200out:
201	if (err) {
202		m->tcf_qstats.overlimits++;
203		/* should we be asking for packet to be dropped?
204		 * may make sense for redirect case only
205		 */
206		retval = TC_ACT_SHOT;
207	} else {
208		retval = m->tcf_action;
209	}
210	spin_unlock(&m->tcf_lock);
211
212	return retval;
213}
214
215static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 
 
 
 
 
 
 
 
 
 
 
216{
217	unsigned char *b = skb_tail_pointer(skb);
218	struct tcf_mirred *m = a->priv;
219	struct tc_mirred opt = {
220		.index   = m->tcf_index,
221		.action  = m->tcf_action,
222		.refcnt  = m->tcf_refcnt - ref,
223		.bindcnt = m->tcf_bindcnt - bind,
224		.eaction = m->tcfm_eaction,
225		.ifindex = m->tcfm_ifindex,
226	};
 
227	struct tcf_t t;
228
 
 
 
 
 
 
 
229	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
230		goto nla_put_failure;
231	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
232	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
233	t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
234	if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
235		goto nla_put_failure;
 
 
236	return skb->len;
237
238nla_put_failure:
 
239	nlmsg_trim(skb, b);
240	return -1;
241}
242
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
243static int mirred_device_event(struct notifier_block *unused,
244			       unsigned long event, void *ptr)
245{
246	struct net_device *dev = ptr;
247	struct tcf_mirred *m;
248
249	if (event == NETDEV_UNREGISTER)
 
 
250		list_for_each_entry(m, &mirred_list, tcfm_list) {
251			if (m->tcfm_dev == dev) {
 
252				dev_put(dev);
253				m->tcfm_dev = NULL;
 
 
 
254			}
 
255		}
 
 
256
257	return NOTIFY_DONE;
258}
259
260static struct notifier_block mirred_device_notifier = {
261	.notifier_call = mirred_device_event,
262};
263
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
264
265static struct tc_action_ops act_mirred_ops = {
266	.kind		=	"mirred",
267	.hinfo		=	&mirred_hash_info,
268	.type		=	TCA_ACT_MIRRED,
269	.capab		=	TCA_CAP_NONE,
270	.owner		=	THIS_MODULE,
271	.act		=	tcf_mirred,
 
272	.dump		=	tcf_mirred_dump,
273	.cleanup	=	tcf_mirred_cleanup,
274	.lookup		=	tcf_hash_search,
275	.init		=	tcf_mirred_init,
276	.walk		=	tcf_generic_walker
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
277};
278
279MODULE_AUTHOR("Jamal Hadi Salim(2002)");
280MODULE_DESCRIPTION("Device Mirror/redirect actions");
281MODULE_LICENSE("GPL");
282
283static int __init mirred_init_module(void)
284{
285	int err = register_netdevice_notifier(&mirred_device_notifier);
286	if (err)
287		return err;
288
289	pr_info("Mirror/redirect action on\n");
290	return tcf_register_action(&act_mirred_ops);
 
 
 
 
291}
292
293static void __exit mirred_cleanup_module(void)
294{
 
295	unregister_netdevice_notifier(&mirred_device_notifier);
296	tcf_unregister_action(&act_mirred_ops);
297}
298
299module_init(mirred_init_module);
300module_exit(mirred_cleanup_module);