[linux-2.6-block.git] / net / sched / act_mirred.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/sched/act_mirred.c	packet mirroring and redirect actions
 *
 * Authors:	Jamal Hadi Salim (2002-4)
 *
 * TODO: Add ingress support (and socket redirect support)
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/gfp.h>
#include <linux/if_arp.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <linux/tc_act/tc_mirred.h>
#include <net/tc_act/tc_mirred.h>

static LIST_HEAD(mirred_list);
static DEFINE_SPINLOCK(mirred_list_lock);

static bool tcf_mirred_is_act_redirect(int action)
{
	return action == TCA_EGRESS_REDIR || action == TCA_INGRESS_REDIR;
}

static bool tcf_mirred_act_wants_ingress(int action)
{
	switch (action) {
	case TCA_EGRESS_REDIR:
	case TCA_EGRESS_MIRROR:
		return false;
	case TCA_INGRESS_REDIR:
	case TCA_INGRESS_MIRROR:
		return true;
	default:
		BUG();
	}
}

static bool tcf_mirred_can_reinsert(int action)
{
	switch (action) {
	case TC_ACT_SHOT:
	case TC_ACT_STOLEN:
	case TC_ACT_QUEUED:
	case TC_ACT_TRAP:
		return true;
	}
	return false;
}

static struct net_device *tcf_mirred_dev_dereference(struct tcf_mirred *m)
{
	return rcu_dereference_protected(m->tcfm_dev,
					 lockdep_is_held(&m->tcf_lock));
}

static void tcf_mirred_release(struct tc_action *a)
{
	struct tcf_mirred *m = to_mirred(a);
	struct net_device *dev;

	spin_lock(&mirred_list_lock);
	list_del(&m->tcfm_list);
	spin_unlock(&mirred_list_lock);

	/* last reference to action, no need to lock */
	dev = rcu_dereference_protected(m->tcfm_dev, 1);
	if (dev)
		dev_put(dev);
}

static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
	[TCA_MIRRED_PARMS]	= { .len = sizeof(struct tc_mirred) },
};

static unsigned int mirred_net_id;
static struct tc_action_ops act_mirred_ops;

static int tcf_mirred_init(struct net *net, struct nlattr *nla,
			   struct nlattr *est, struct tc_action **a,
			   int ovr, int bind, bool rtnl_held,
			   struct tcf_proto *tp,
			   struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, mirred_net_id);
	struct nlattr *tb[TCA_MIRRED_MAX + 1];
	struct tcf_chain *goto_ch = NULL;
	bool mac_header_xmit = false;
	struct tc_mirred *parm;
	struct tcf_mirred *m;
	struct net_device *dev;
	bool exists = false;
	int ret, err;

	if (!nla) {
		NL_SET_ERR_MSG_MOD(extack, "Mirred requires attributes to be passed");
		return -EINVAL;
	}
	ret = nla_parse_nested_deprecated(tb, TCA_MIRRED_MAX, nla,
					  mirred_policy, extack);
	if (ret < 0)
		return ret;
	if (!tb[TCA_MIRRED_PARMS]) {
		NL_SET_ERR_MSG_MOD(extack, "Missing required mirred parameters");
		return -EINVAL;
	}
	parm = nla_data(tb[TCA_MIRRED_PARMS]);

	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
	if (err < 0)
		return err;
	exists = err;
	if (exists && bind)
		return 0;

	switch (parm->eaction) {
	case TCA_EGRESS_MIRROR:
	case TCA_EGRESS_REDIR:
	case TCA_INGRESS_REDIR:
	case TCA_INGRESS_MIRROR:
		break;
	default:
		if (exists)
			tcf_idr_release(*a, bind);
		else
			tcf_idr_cleanup(tn, parm->index);
		NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option");
		return -EINVAL;
	}

	if (!exists) {
		if (!parm->ifindex) {
			tcf_idr_cleanup(tn, parm->index);
			NL_SET_ERR_MSG_MOD(extack, "Specified device does not exist");
			return -EINVAL;
		}
		ret = tcf_idr_create(tn, parm->index, est, a,
				     &act_mirred_ops, bind, true);
		if (ret) {
			tcf_idr_cleanup(tn, parm->index);
			return ret;
		}
		ret = ACT_P_CREATED;
	} else if (!ovr) {
		tcf_idr_release(*a, bind);
		return -EEXIST;
	}

	m = to_mirred(*a);
	if (ret == ACT_P_CREATED)
		INIT_LIST_HEAD(&m->tcfm_list);

	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
	if (err < 0)
		goto release_idr;

	spin_lock_bh(&m->tcf_lock);

	if (parm->ifindex) {
		dev = dev_get_by_index(net, parm->ifindex);
		if (!dev) {
			spin_unlock_bh(&m->tcf_lock);
			err = -ENODEV;
			goto put_chain;
		}
		mac_header_xmit = dev_is_mac_header_xmit(dev);
		rcu_swap_protected(m->tcfm_dev, dev,
				   lockdep_is_held(&m->tcf_lock));
		if (dev)
			dev_put(dev);
		m->tcfm_mac_header_xmit = mac_header_xmit;
	}
	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
	m->tcfm_eaction = parm->eaction;
	spin_unlock_bh(&m->tcf_lock);
	if (goto_ch)
		tcf_chain_put_by_act(goto_ch);

	if (ret == ACT_P_CREATED) {
		spin_lock(&mirred_list_lock);
		list_add(&m->tcfm_list, &mirred_list);
		spin_unlock(&mirred_list_lock);

		tcf_idr_insert(tn, *a);
	}

	return ret;
put_chain:
	if (goto_ch)
		tcf_chain_put_by_act(goto_ch);
release_idr:
	tcf_idr_release(*a, bind);
	return err;
}

static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
			  struct tcf_result *res)
{
	struct tcf_mirred *m = to_mirred(a);
	struct sk_buff *skb2 = skb;
	bool m_mac_header_xmit;
	struct net_device *dev;
	int retval, err = 0;
	bool use_reinsert;
	bool want_ingress;
	bool is_redirect;
	int m_eaction;
	int mac_len;

	tcf_lastuse_update(&m->tcf_tm);
	bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);

	m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit);
	m_eaction = READ_ONCE(m->tcfm_eaction);
	retval = READ_ONCE(m->tcf_action);
	dev = rcu_dereference_bh(m->tcfm_dev);
	if (unlikely(!dev)) {
		pr_notice_once("tc mirred: target device is gone\n");
		goto out;
	}

	if (unlikely(!(dev->flags & IFF_UP))) {
		net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
				       dev->name);
		goto out;
	}

	/* we could easily avoid the clone only if called by ingress and clsact;
	 * since we can't easily detect the clsact caller, skip clone only for
	 * ingress - that covers the TC S/W datapath.
	 */
	is_redirect = tcf_mirred_is_act_redirect(m_eaction);
	use_reinsert = skb_at_tc_ingress(skb) && is_redirect &&
		       tcf_mirred_can_reinsert(retval);
	if (!use_reinsert) {
		skb2 = skb_clone(skb, GFP_ATOMIC);
		if (!skb2)
			goto out;
	}

	/* If action's target direction differs than filter's direction,
	 * and devices expect a mac header on xmit, then mac push/pull is
	 * needed.
	 */
	want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
	if (skb_at_tc_ingress(skb) != want_ingress && m_mac_header_xmit) {
		if (!skb_at_tc_ingress(skb)) {
			/* caught at egress, act ingress: pull mac */
			mac_len = skb_network_header(skb) - skb_mac_header(skb);
			skb_pull_rcsum(skb2, mac_len);
		} else {
			/* caught at ingress, act egress: push mac */
			skb_push_rcsum(skb2, skb->mac_len);
		}
	}

	skb2->skb_iif = skb->dev->ifindex;
	skb2->dev = dev;

	/* mirror is always swallowed */
	if (is_redirect) {
		skb2->tc_redirected = 1;
		skb2->tc_from_ingress = skb2->tc_at_ingress;
		if (skb2->tc_from_ingress)
			skb2->tstamp = 0;
		/* let's the caller reinsert the packet, if possible */
		if (use_reinsert) {
			res->ingress = want_ingress;
			res->qstats = this_cpu_ptr(m->common.cpu_qstats);
			return TC_ACT_REINSERT;
		}
	}

	if (!want_ingress)
		err = dev_queue_xmit(skb2);
	else
		err = netif_receive_skb(skb2);

	if (err) {
out:
		qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
		if (tcf_mirred_is_act_redirect(m_eaction))
			retval = TC_ACT_SHOT;
	}

	return retval;
}

static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
			     u64 lastuse, bool hw)
{
	struct tcf_mirred *m = to_mirred(a);
	struct tcf_t *tm = &m->tcf_tm;

	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
	if (hw)
		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
				   bytes, packets);
	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
}

static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
			   int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_mirred *m = to_mirred(a);
	struct tc_mirred opt = {
		.index   = m->tcf_index,
		.refcnt  = refcount_read(&m->tcf_refcnt) - ref,
		.bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
	};
	struct net_device *dev;
	struct tcf_t t;

	spin_lock_bh(&m->tcf_lock);
	opt.action = m->tcf_action;
	opt.eaction = m->tcfm_eaction;
	dev = tcf_mirred_dev_dereference(m);
	if (dev)
		opt.ifindex = dev->ifindex;

	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;

	tcf_tm_dump(&t, &m->tcf_tm);
	if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
		goto nla_put_failure;
	spin_unlock_bh(&m->tcf_lock);

	return skb->len;

nla_put_failure:
	spin_unlock_bh(&m->tcf_lock);
	nlmsg_trim(skb, b);
	return -1;
}

static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
			     struct netlink_callback *cb, int type,
			     const struct tc_action_ops *ops,
			     struct netlink_ext_ack *extack)
{
	struct tc_action_net *tn = net_generic(net, mirred_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
}

static int tcf_mirred_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, mirred_net_id);

	return tcf_idr_search(tn, a, index);
}

static int mirred_device_event(struct notifier_block *unused,
			       unsigned long event, void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	struct tcf_mirred *m;

	ASSERT_RTNL();
	if (event == NETDEV_UNREGISTER) {
		spin_lock(&mirred_list_lock);
		list_for_each_entry(m, &mirred_list, tcfm_list) {
			spin_lock_bh(&m->tcf_lock);
			if (tcf_mirred_dev_dereference(m) == dev) {
				dev_put(dev);
				/* Note : no rcu grace period necessary, as
				 * net_device are already rcu protected.
				 */
				RCU_INIT_POINTER(m->tcfm_dev, NULL);
			}
			spin_unlock_bh(&m->tcf_lock);
		}
		spin_unlock(&mirred_list_lock);
	}

	return NOTIFY_DONE;
}

static struct notifier_block mirred_device_notifier = {
	.notifier_call = mirred_device_event,
};

static struct net_device *tcf_mirred_get_dev(const struct tc_action *a)
{
	struct tcf_mirred *m = to_mirred(a);
	struct net_device *dev;

	rcu_read_lock();
	dev = rcu_dereference(m->tcfm_dev);
	if (dev)
		dev_hold(dev);
	rcu_read_unlock();

	return dev;
}

static void tcf_mirred_put_dev(struct net_device *dev)
{
	dev_put(dev);
}

static struct tc_action_ops act_mirred_ops = {
	.kind		=	"mirred",
	.id		=	TCA_ID_MIRRED,
	.owner		=	THIS_MODULE,
	.act		=	tcf_mirred_act,
	.stats_update	=	tcf_stats_update,
	.dump		=	tcf_mirred_dump,
	.cleanup	=	tcf_mirred_release,
	.init		=	tcf_mirred_init,
	.walk		=	tcf_mirred_walker,
	.lookup		=	tcf_mirred_search,
	.size		=	sizeof(struct tcf_mirred),
	.get_dev	=	tcf_mirred_get_dev,
	.put_dev	=	tcf_mirred_put_dev,
};

static __net_init int mirred_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, mirred_net_id);

	return tc_action_net_init(tn, &act_mirred_ops);
}

static void __net_exit mirred_exit_net(struct list_head *net_list)
{
	tc_action_net_exit(net_list, mirred_net_id);
}

static struct pernet_operations mirred_net_ops = {
	.init = mirred_init_net,
	.exit_batch = mirred_exit_net,
	.id   = &mirred_net_id,
	.size = sizeof(struct tc_action_net),
};

MODULE_AUTHOR("Jamal Hadi Salim(2002)");
MODULE_DESCRIPTION("Device Mirror/redirect actions");
MODULE_LICENSE("GPL");

static int __init mirred_init_module(void)
{
	int err = register_netdevice_notifier(&mirred_device_notifier);
	if (err)
		return err;

	pr_info("Mirror/redirect action on\n");
	return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
}

static void __exit mirred_cleanup_module(void)
{
	tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
	unregister_netdevice_notifier(&mirred_device_notifier);
}

module_init(mirred_init_module);
module_exit(mirred_cleanup_module);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4	2	/*
0c6965dd	3	* net/sched/act_mirred.c packet mirroring and redirect actions
1da177e4	4	*
1da177e4 LT	5	* Authors: Jamal Hadi Salim (2002-4)
	6	*
	7	* TODO: Add ingress support (and socket redirect support)
1da177e4 LT	8	*/
1da177e4 LT	9
1da177e4 LT	10	#include <linux/types.h>
1da177e4 LT	11	#include <linux/kernel.h>
1da177e4	12	#include <linux/string.h>
1da177e4	13	#include <linux/errno.h>
1da177e4 LT	14	#include <linux/skbuff.h>
	15	#include <linux/rtnetlink.h>
	16	#include <linux/module.h>
	17	#include <linux/init.h>
5a0e3ad6	18	#include <linux/gfp.h>
c491680f	19	#include <linux/if_arp.h>
881d966b	20	#include <net/net_namespace.h>
dc5fc579	21	#include <net/netlink.h>
1da177e4	22	#include <net/pkt_sched.h>
e5cf1baf	23	#include <net/pkt_cls.h>
1da177e4 LT	24	#include <linux/tc_act/tc_mirred.h>
	25	#include <net/tc_act/tc_mirred.h>
	26
3b87956e	27	static LIST_HEAD(mirred_list);
4e232818	28	static DEFINE_SPINLOCK(mirred_list_lock);
1da177e4	29
53592b36 SL	30	static bool tcf_mirred_is_act_redirect(int action)
	31	{
	32	return action == TCA_EGRESS_REDIR \|\| action == TCA_INGRESS_REDIR;
	33	}
	34
8dc07fdb	35	static bool tcf_mirred_act_wants_ingress(int action)
53592b36 SL	36	{
	37	switch (action) {
	38	case TCA_EGRESS_REDIR:
	39	case TCA_EGRESS_MIRROR:
8dc07fdb	40	return false;
53592b36 SL	41	case TCA_INGRESS_REDIR:
53592b36 SL	42	case TCA_INGRESS_MIRROR:
8dc07fdb	43	return true;
53592b36 SL	44	default:
	45	BUG();
	46	}
	47	}
	48
e5cf1baf PA	49	static bool tcf_mirred_can_reinsert(int action)
	50	{
	51	switch (action) {
	52	case TC_ACT_SHOT:
	53	case TC_ACT_STOLEN:
	54	case TC_ACT_QUEUED:
	55	case TC_ACT_TRAP:
	56	return true;
	57	}
	58	return false;
	59	}
	60
4e232818 VB	61	static struct net_device tcf_mirred_dev_dereference(struct tcf_mirred m)
	62	{
	63	return rcu_dereference_protected(m->tcfm_dev,
	64	lockdep_is_held(&m->tcf_lock));
	65	}
	66
9a63b255	67	static void tcf_mirred_release(struct tc_action *a)
1da177e4	68	{
86062033	69	struct tcf_mirred *m = to_mirred(a);
dc327f89	70	struct net_device *dev;
2ee22a90	71
4e232818	72	spin_lock(&mirred_list_lock);
a5b5c958	73	list_del(&m->tcfm_list);
4e232818 VB	74	spin_unlock(&mirred_list_lock);
	75
	76	/* last reference to action, no need to lock */
	77	dev = rcu_dereference_protected(m->tcfm_dev, 1);
2ee22a90 ED	78	if (dev)
2ee22a90 ED	79	dev_put(dev);
1da177e4 LT	80	}
1da177e4 LT	81
53b2bf3f PM	82	static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
	83	[TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
	84	};
	85
c7d03a00	86	static unsigned int mirred_net_id;
a85a970a	87	static struct tc_action_ops act_mirred_ops;
ddf97ccd	88
c1b52739	89	static int tcf_mirred_init(struct net net, struct nlattr nla,
789871bb VB	90	struct nlattr est, struct tc_action *a,
789871bb VB	91	int ovr, int bind, bool rtnl_held,
85d0966f	92	struct tcf_proto *tp,
789871bb	93	struct netlink_ext_ack *extack)
1da177e4	94	{
ddf97ccd	95	struct tc_action_net *tn = net_generic(net, mirred_net_id);
7ba699c6	96	struct nlattr *tb[TCA_MIRRED_MAX + 1];
ff9721d3	97	struct tcf_chain *goto_ch = NULL;
16577923	98	bool mac_header_xmit = false;
1da177e4	99	struct tc_mirred *parm;
e9ce1cd3	100	struct tcf_mirred *m;
b76965e0	101	struct net_device *dev;
b2313077	102	bool exists = false;
0190c1d4	103	int ret, err;
1da177e4	104
1d4760c7 AA	105	if (!nla) {
1d4760c7 AA	106	NL_SET_ERR_MSG_MOD(extack, "Mirred requires attributes to be passed");
1da177e4	107	return -EINVAL;
1d4760c7	108	}
8cb08174 JB	109	ret = nla_parse_nested_deprecated(tb, TCA_MIRRED_MAX, nla,
8cb08174 JB	110	mirred_policy, extack);
b76965e0 CG	111	if (ret < 0)
b76965e0 CG	112	return ret;
1d4760c7 AA	113	if (!tb[TCA_MIRRED_PARMS]) {
1d4760c7 AA	114	NL_SET_ERR_MSG_MOD(extack, "Missing required mirred parameters");
1da177e4	115	return -EINVAL;
1d4760c7	116	}
7ba699c6	117	parm = nla_data(tb[TCA_MIRRED_PARMS]);
87dfbdc6	118
0190c1d4 VB	119	err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
	120	if (err < 0)
	121	return err;
	122	exists = err;
87dfbdc6 JHS	123	if (exists && bind)
	124	return 0;
	125
b76965e0 CG	126	switch (parm->eaction) {
	127	case TCA_EGRESS_MIRROR:
	128	case TCA_EGRESS_REDIR:
53592b36 SL	129	case TCA_INGRESS_REDIR:
53592b36 SL	130	case TCA_INGRESS_MIRROR:
b76965e0 CG	131	break;
b76965e0 CG	132	default:
87dfbdc6	133	if (exists)
65a206c0	134	tcf_idr_release(*a, bind);
0190c1d4 VB	135	else
0190c1d4 VB	136	tcf_idr_cleanup(tn, parm->index);
1d4760c7	137	NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option");
b76965e0 CG	138	return -EINVAL;
b76965e0 CG	139	}
1da177e4	140
87dfbdc6	141	if (!exists) {
4e232818	142	if (!parm->ifindex) {
0190c1d4	143	tcf_idr_cleanup(tn, parm->index);
1d4760c7	144	NL_SET_ERR_MSG_MOD(extack, "Specified device does not exist");
1da177e4	145	return -EINVAL;
1d4760c7	146	}
65a206c0 CM	147	ret = tcf_idr_create(tn, parm->index, est, a,
65a206c0 CM	148	&act_mirred_ops, bind, true);
0190c1d4 VB	149	if (ret) {
0190c1d4 VB	150	tcf_idr_cleanup(tn, parm->index);
86062033	151	return ret;
0190c1d4	152	}
1da177e4	153	ret = ACT_P_CREATED;
4e8ddd7f	154	} else if (!ovr) {
65a206c0	155	tcf_idr_release(*a, bind);
4e8ddd7f	156	return -EEXIST;
1da177e4	157	}
064c5d68 JH	158
	159	m = to_mirred(*a);
	160	if (ret == ACT_P_CREATED)
	161	INIT_LIST_HEAD(&m->tcfm_list);
	162
ff9721d3 DC	163	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
	164	if (err < 0)
	165	goto release_idr;
	166
653cd284	167	spin_lock_bh(&m->tcf_lock);
4e232818 VB	168
	169	if (parm->ifindex) {
	170	dev = dev_get_by_index(net, parm->ifindex);
	171	if (!dev) {
653cd284	172	spin_unlock_bh(&m->tcf_lock);
ff9721d3 DC	173	err = -ENODEV;
ff9721d3 DC	174	goto put_chain;
4e232818 VB	175	}
	176	mac_header_xmit = dev_is_mac_header_xmit(dev);
	177	rcu_swap_protected(m->tcfm_dev, dev,
	178	lockdep_is_held(&m->tcf_lock));
	179	if (dev)
	180	dev_put(dev);
16577923	181	m->tcfm_mac_header_xmit = mac_header_xmit;
1da177e4	182	}
ff9721d3 DC	183	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
ff9721d3 DC	184	m->tcfm_eaction = parm->eaction;
653cd284	185	spin_unlock_bh(&m->tcf_lock);
ff9721d3 DC	186	if (goto_ch)
ff9721d3 DC	187	tcf_chain_put_by_act(goto_ch);
2ee22a90	188
3b87956e	189	if (ret == ACT_P_CREATED) {
4e232818	190	spin_lock(&mirred_list_lock);
3b87956e	191	list_add(&m->tcfm_list, &mirred_list);
4e232818 VB	192	spin_unlock(&mirred_list_lock);
4e232818 VB	193
65a206c0	194	tcf_idr_insert(tn, *a);
3b87956e	195	}
1da177e4	196
1da177e4	197	return ret;
ff9721d3 DC	198	put_chain:
	199	if (goto_ch)
	200	tcf_chain_put_by_act(goto_ch);
	201	release_idr:
	202	tcf_idr_release(*a, bind);
	203	return err;
1da177e4 LT	204	}
1da177e4 LT	205
7c5790c4 JHS	206	static int tcf_mirred_act(struct sk_buff skb, const struct tc_action a,
7c5790c4 JHS	207	struct tcf_result *res)
1da177e4	208	{
a85a970a	209	struct tcf_mirred *m = to_mirred(a);
e5cf1baf	210	struct sk_buff *skb2 = skb;
53592b36	211	bool m_mac_header_xmit;
1da177e4	212	struct net_device *dev;
53592b36	213	int retval, err = 0;
e5cf1baf PA	214	bool use_reinsert;
	215	bool want_ingress;
	216	bool is_redirect;
53592b36 SL	217	int m_eaction;
53592b36 SL	218	int mac_len;
1da177e4	219
2ee22a90	220	tcf_lastuse_update(&m->tcf_tm);
2ee22a90	221	bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
1da177e4	222
53592b36 SL	223	m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit);
53592b36 SL	224	m_eaction = READ_ONCE(m->tcfm_eaction);
2ee22a90	225	retval = READ_ONCE(m->tcf_action);
7fd4b288	226	dev = rcu_dereference_bh(m->tcfm_dev);
2ee22a90 ED	227	if (unlikely(!dev)) {
2ee22a90 ED	228	pr_notice_once("tc mirred: target device is gone\n");
3b87956e	229	goto out;
	230	}
	231
2ee22a90	232	if (unlikely(!(dev->flags & IFF_UP))) {
e87cc472 JP	233	net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
e87cc472 JP	234	dev->name);
feed1f17	235	goto out;
1da177e4 LT	236	}
1da177e4 LT	237
e5cf1baf PA	238	/* we could easily avoid the clone only if called by ingress and clsact;
	239	* since we can't easily detect the clsact caller, skip clone only for
	240	* ingress - that covers the TC S/W datapath.
	241	*/
	242	is_redirect = tcf_mirred_is_act_redirect(m_eaction);
	243	use_reinsert = skb_at_tc_ingress(skb) && is_redirect &&
	244	tcf_mirred_can_reinsert(retval);
	245	if (!use_reinsert) {
	246	skb2 = skb_clone(skb, GFP_ATOMIC);
	247	if (!skb2)
	248	goto out;
	249	}
1da177e4	250
53592b36 SL	251	/* If action's target direction differs than filter's direction,
	252	* and devices expect a mac header on xmit, then mac push/pull is
	253	* needed.
	254	*/
e5cf1baf PA	255	want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
e5cf1baf PA	256	if (skb_at_tc_ingress(skb) != want_ingress && m_mac_header_xmit) {
a5135bcf	257	if (!skb_at_tc_ingress(skb)) {
53592b36 SL	258	/* caught at egress, act ingress: pull mac */
	259	mac_len = skb_network_header(skb) - skb_mac_header(skb);
	260	skb_pull_rcsum(skb2, mac_len);
	261	} else {
	262	/* caught at ingress, act egress: push mac */
82a31b92	263	skb_push_rcsum(skb2, skb->mac_len);
53592b36	264	}
feed1f17	265	}
1da177e4	266
e5cf1baf PA	267	skb2->skb_iif = skb->dev->ifindex;
	268	skb2->dev = dev;
	269
1da177e4	270	/* mirror is always swallowed */
e5cf1baf	271	if (is_redirect) {
bc31c905 WB	272	skb2->tc_redirected = 1;
bc31c905 WB	273	skb2->tc_from_ingress = skb2->tc_at_ingress;
7236ead1 ED	274	if (skb2->tc_from_ingress)
7236ead1 ED	275	skb2->tstamp = 0;
e5cf1baf PA	276	/* let's the caller reinsert the packet, if possible */
	277	if (use_reinsert) {
	278	res->ingress = want_ingress;
	279	res->qstats = this_cpu_ptr(m->common.cpu_qstats);
	280	return TC_ACT_REINSERT;
	281	}
bc31c905	282	}
1da177e4	283
e5cf1baf	284	if (!want_ingress)
53592b36 SL	285	err = dev_queue_xmit(skb2);
	286	else
	287	err = netif_receive_skb(skb2);
feed1f17	288
feed1f17	289	if (err) {
2ee22a90 ED	290	out:
2ee22a90 ED	291	qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
53592b36	292	if (tcf_mirred_is_act_redirect(m_eaction))
16c0b164	293	retval = TC_ACT_SHOT;
2ee22a90	294	}
feed1f17 CG	295
feed1f17 CG	296	return retval;
1da177e4 LT	297	}
1da177e4 LT	298
9798e6fe	299	static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
28169aba	300	u64 lastuse, bool hw)
9798e6fe	301	{
5712bf9c PB	302	struct tcf_mirred *m = to_mirred(a);
	303	struct tcf_t *tm = &m->tcf_tm;
	304
9798e6fe	305	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
28169aba EC	306	if (hw)
	307	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
	308	bytes, packets);
3bb23421	309	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
9798e6fe JK	310	}
9798e6fe JK	311
5a7a5555 JHS	312	static int tcf_mirred_dump(struct sk_buff skb, struct tc_action a, int bind,
5a7a5555 JHS	313	int ref)
1da177e4	314	{
27a884dc	315	unsigned char *b = skb_tail_pointer(skb);
a85a970a	316	struct tcf_mirred *m = to_mirred(a);
1c40be12 ED	317	struct tc_mirred opt = {
1c40be12 ED	318	.index = m->tcf_index,
036bb443 VB	319	.refcnt = refcount_read(&m->tcf_refcnt) - ref,
036bb443 VB	320	.bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
1c40be12	321	};
4e232818	322	struct net_device *dev;
1da177e4 LT	323	struct tcf_t t;
1da177e4 LT	324
653cd284	325	spin_lock_bh(&m->tcf_lock);
4e232818 VB	326	opt.action = m->tcf_action;
	327	opt.eaction = m->tcfm_eaction;
	328	dev = tcf_mirred_dev_dereference(m);
	329	if (dev)
	330	opt.ifindex = dev->ifindex;
	331
1b34ec43 DM	332	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
1b34ec43 DM	333	goto nla_put_failure;
48d8ee16 JHS	334
48d8ee16 JHS	335	tcf_tm_dump(&t, &m->tcf_tm);
9854518e	336	if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
1b34ec43	337	goto nla_put_failure;
653cd284	338	spin_unlock_bh(&m->tcf_lock);
4e232818	339
1da177e4 LT	340	return skb->len;
1da177e4 LT	341
7ba699c6	342	nla_put_failure:
653cd284	343	spin_unlock_bh(&m->tcf_lock);
dc5fc579	344	nlmsg_trim(skb, b);
1da177e4 LT	345	return -1;
	346	}
	347
ddf97ccd WC	348	static int tcf_mirred_walker(struct net net, struct sk_buff skb,
ddf97ccd WC	349	struct netlink_callback *cb, int type,
41780105 AA	350	const struct tc_action_ops *ops,
41780105 AA	351	struct netlink_ext_ack *extack)
ddf97ccd WC	352	{
	353	struct tc_action_net *tn = net_generic(net, mirred_net_id);
	354
b3620145	355	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
ddf97ccd WC	356	}
ddf97ccd WC	357
f061b48c	358	static int tcf_mirred_search(struct net net, struct tc_action *a, u32 index)
ddf97ccd WC	359	{
	360	struct tc_action_net *tn = net_generic(net, mirred_net_id);
	361
65a206c0	362	return tcf_idr_search(tn, a, index);
ddf97ccd WC	363	}
ddf97ccd WC	364
3b87956e	365	static int mirred_device_event(struct notifier_block *unused,
	366	unsigned long event, void *ptr)
	367	{
351638e7	368	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3b87956e	369	struct tcf_mirred *m;
3b87956e	370
2ee22a90	371	ASSERT_RTNL();
6bd00b85	372	if (event == NETDEV_UNREGISTER) {
4e232818	373	spin_lock(&mirred_list_lock);
3b87956e	374	list_for_each_entry(m, &mirred_list, tcfm_list) {
653cd284	375	spin_lock_bh(&m->tcf_lock);
4e232818	376	if (tcf_mirred_dev_dereference(m) == dev) {
3b87956e	377	dev_put(dev);
2ee22a90 ED	378	/* Note : no rcu grace period necessary, as
	379	* net_device are already rcu protected.
	380	*/
	381	RCU_INIT_POINTER(m->tcfm_dev, NULL);
3b87956e	382	}
653cd284	383	spin_unlock_bh(&m->tcf_lock);
3b87956e	384	}
4e232818	385	spin_unlock(&mirred_list_lock);
6bd00b85	386	}
3b87956e	387
	388	return NOTIFY_DONE;
	389	}
	390
	391	static struct notifier_block mirred_device_notifier = {
	392	.notifier_call = mirred_device_event,
	393	};
	394
843e79d0	395	static struct net_device tcf_mirred_get_dev(const struct tc_action a)
255cb304	396	{
843e79d0	397	struct tcf_mirred *m = to_mirred(a);
4e232818	398	struct net_device *dev;
84a75b32	399
4e232818 VB	400	rcu_read_lock();
4e232818 VB	401	dev = rcu_dereference(m->tcfm_dev);
84a75b32 VB	402	if (dev)
84a75b32 VB	403	dev_hold(dev);
4e232818	404	rcu_read_unlock();
255cb304	405
84a75b32 VB	406	return dev;
	407	}
	408
	409	static void tcf_mirred_put_dev(struct net_device *dev)
	410	{
	411	dev_put(dev);
255cb304 HHZ	412	}
255cb304 HHZ	413
1da177e4 LT	414	static struct tc_action_ops act_mirred_ops = {
1da177e4 LT	415	.kind = "mirred",
eddd2cf1	416	.id = TCA_ID_MIRRED,
1da177e4	417	.owner = THIS_MODULE,
7c5790c4	418	.act = tcf_mirred_act,
9798e6fe	419	.stats_update = tcf_stats_update,
1da177e4	420	.dump = tcf_mirred_dump,
86062033	421	.cleanup = tcf_mirred_release,
1da177e4	422	.init = tcf_mirred_init,
ddf97ccd WC	423	.walk = tcf_mirred_walker,
ddf97ccd WC	424	.lookup = tcf_mirred_search,
a85a970a	425	.size = sizeof(struct tcf_mirred),
843e79d0	426	.get_dev = tcf_mirred_get_dev,
84a75b32	427	.put_dev = tcf_mirred_put_dev,
ddf97ccd WC	428	};
	429
	430	static __net_init int mirred_init_net(struct net *net)
	431	{
	432	struct tc_action_net *tn = net_generic(net, mirred_net_id);
	433
c7e460ce	434	return tc_action_net_init(tn, &act_mirred_ops);
ddf97ccd WC	435	}
ddf97ccd WC	436
039af9c6	437	static void __net_exit mirred_exit_net(struct list_head *net_list)
ddf97ccd	438	{
039af9c6	439	tc_action_net_exit(net_list, mirred_net_id);
ddf97ccd WC	440	}
	441
	442	static struct pernet_operations mirred_net_ops = {
	443	.init = mirred_init_net,
039af9c6	444	.exit_batch = mirred_exit_net,
ddf97ccd WC	445	.id = &mirred_net_id,
ddf97ccd WC	446	.size = sizeof(struct tc_action_net),
1da177e4 LT	447	};
	448
	449	MODULE_AUTHOR("Jamal Hadi Salim(2002)");
	450	MODULE_DESCRIPTION("Device Mirror/redirect actions");
	451	MODULE_LICENSE("GPL");
	452
e9ce1cd3	453	static int __init mirred_init_module(void)
1da177e4	454	{
3b87956e	455	int err = register_netdevice_notifier(&mirred_device_notifier);
	456	if (err)
	457	return err;
	458
6ff9c364	459	pr_info("Mirror/redirect action on\n");
ddf97ccd	460	return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
1da177e4 LT	461	}
1da177e4 LT	462
e9ce1cd3	463	static void __exit mirred_cleanup_module(void)
1da177e4	464	{
ddf97ccd	465	tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
568a153a	466	unregister_netdevice_notifier(&mirred_device_notifier);
1da177e4 LT	467	}
	468
	469	module_init(mirred_init_module);
	470	module_exit(mirred_cleanup_module);