[linux.git] / net / sched / act_mirred.c

/*
 * net/sched/mirred.c	packet mirroring and redirect actions
 *
 *		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.
 *
 * 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 <net/net_namespace.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_mirred.h>
#include <net/tc_act/tc_mirred.h>

#include <linux/if_arp.h>

#define MIRRED_TAB_MASK     7
static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
static u32 mirred_idx_gen;
static DEFINE_RWLOCK(mirred_lock);
static LIST_HEAD(mirred_list);

static struct tcf_hashinfo mirred_hash_info = {
	.htab	=	tcf_mirred_ht,
	.hmask	=	MIRRED_TAB_MASK,
	.lock	=	&mirred_lock,
};

static int tcf_mirred_release(struct tcf_mirred *m, int bind)
{
	if (m) {
		if (bind)
			m->tcf_bindcnt--;
		m->tcf_refcnt--;
		if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
			list_del(&m->tcfm_list);
			if (m->tcfm_dev)
				dev_put(m->tcfm_dev);
			tcf_hash_destroy(&m->common, &mirred_hash_info);
			return 1;
		}
	}
	return 0;
}

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

static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
			   struct tc_action *a, int ovr, int bind)
{
	struct nlattr *tb[TCA_MIRRED_MAX + 1];
	struct tc_mirred *parm;
	struct tcf_mirred *m;
	struct tcf_common *pc;
	struct net_device *dev;
	int ret, ok_push = 0;

	if (nla == NULL)
		return -EINVAL;
	ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
	if (ret < 0)
		return ret;
	if (tb[TCA_MIRRED_PARMS] == NULL)
		return -EINVAL;
	parm = nla_data(tb[TCA_MIRRED_PARMS]);
	switch (parm->eaction) {
	case TCA_EGRESS_MIRROR:
	case TCA_EGRESS_REDIR:
		break;
	default:
		return -EINVAL;
	}
	if (parm->ifindex) {
		dev = __dev_get_by_index(&init_net, parm->ifindex);
		if (dev == NULL)
			return -ENODEV;
		switch (dev->type) {
		case ARPHRD_TUNNEL:
		case ARPHRD_TUNNEL6:
		case ARPHRD_SIT:
		case ARPHRD_IPGRE:
		case ARPHRD_VOID:
		case ARPHRD_NONE:
			ok_push = 0;
			break;
		default:
			ok_push = 1;
			break;
		}
	} else {
		dev = NULL;
	}

	pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
	if (!pc) {
		if (dev == NULL)
			return -EINVAL;
		pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
				     &mirred_idx_gen, &mirred_hash_info);
		if (IS_ERR(pc))
			return PTR_ERR(pc);
		ret = ACT_P_CREATED;
	} else {
		if (!ovr) {
			tcf_mirred_release(to_mirred(pc), bind);
			return -EEXIST;
		}
	}
	m = to_mirred(pc);

	spin_lock_bh(&m->tcf_lock);
	m->tcf_action = parm->action;
	m->tcfm_eaction = parm->eaction;
	if (dev != NULL) {
		m->tcfm_ifindex = parm->ifindex;
		if (ret != ACT_P_CREATED)
			dev_put(m->tcfm_dev);
		dev_hold(dev);
		m->tcfm_dev = dev;
		m->tcfm_ok_push = ok_push;
	}
	spin_unlock_bh(&m->tcf_lock);
	if (ret == ACT_P_CREATED) {
		list_add(&m->tcfm_list, &mirred_list);
		tcf_hash_insert(pc, &mirred_hash_info);
	}

	return ret;
}

static int tcf_mirred_cleanup(struct tc_action *a, int bind)
{
	struct tcf_mirred *m = a->priv;

	if (m)
		return tcf_mirred_release(m, bind);
	return 0;
}

static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
		      struct tcf_result *res)
{
	struct tcf_mirred *m = a->priv;
	struct net_device *dev;
	struct sk_buff *skb2;
	u32 at;
	int retval, err = 1;

	spin_lock(&m->tcf_lock);
	m->tcf_tm.lastuse = jiffies;
	bstats_update(&m->tcf_bstats, skb);

	dev = m->tcfm_dev;
	if (!dev) {
		printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
		goto out;
	}

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

	at = G_TC_AT(skb->tc_verd);
	skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
	if (skb2 == NULL)
		goto out;

	if (!(at & AT_EGRESS)) {
		if (m->tcfm_ok_push)
			skb_push(skb2, skb2->dev->hard_header_len);
	}

	/* mirror is always swallowed */
	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
		skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);

	skb2->skb_iif = skb->dev->ifindex;
	skb2->dev = dev;
	err = dev_queue_xmit(skb2);

out:
	if (err) {
		m->tcf_qstats.overlimits++;
		if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
			retval = TC_ACT_SHOT;
		else
			retval = m->tcf_action;
	} else
		retval = m->tcf_action;
	spin_unlock(&m->tcf_lock);

	return retval;
}

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 = a->priv;
	struct tc_mirred opt = {
		.index   = m->tcf_index,
		.action  = m->tcf_action,
		.refcnt  = m->tcf_refcnt - ref,
		.bindcnt = m->tcf_bindcnt - bind,
		.eaction = m->tcfm_eaction,
		.ifindex = m->tcfm_ifindex,
	};
	struct tcf_t t;

	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;
	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
	t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
	if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
		goto nla_put_failure;
	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}

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

	if (event == NETDEV_UNREGISTER)
		list_for_each_entry(m, &mirred_list, tcfm_list) {
			if (m->tcfm_dev == dev) {
				dev_put(dev);
				m->tcfm_dev = NULL;
			}
		}

	return NOTIFY_DONE;
}

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


static struct tc_action_ops act_mirred_ops = {
	.kind		=	"mirred",
	.hinfo		=	&mirred_hash_info,
	.type		=	TCA_ACT_MIRRED,
	.capab		=	TCA_CAP_NONE,
	.owner		=	THIS_MODULE,
	.act		=	tcf_mirred,
	.dump		=	tcf_mirred_dump,
	.cleanup	=	tcf_mirred_cleanup,
	.lookup		=	tcf_hash_search,
	.init		=	tcf_mirred_init,
	.walk		=	tcf_generic_walker
};

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);
}

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

module_init(mirred_init_module);
module_exit(mirred_cleanup_module);
Commit	Line	Data
1da177e4 LT	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
1da177e4 LT	15	#include <linux/types.h>
1da177e4 LT	16	#include <linux/kernel.h>
1da177e4	17	#include <linux/string.h>
1da177e4	18	#include <linux/errno.h>
1da177e4 LT	19	#include <linux/skbuff.h>
	20	#include <linux/rtnetlink.h>
	21	#include <linux/module.h>
	22	#include <linux/init.h>
5a0e3ad6	23	#include <linux/gfp.h>
881d966b	24	#include <net/net_namespace.h>
dc5fc579	25	#include <net/netlink.h>
1da177e4 LT	26	#include <net/pkt_sched.h>
	27	#include <linux/tc_act/tc_mirred.h>
	28	#include <net/tc_act/tc_mirred.h>
	29
1da177e4 LT	30	#include <linux/if_arp.h>
1da177e4 LT	31
e9ce1cd3 DM	32	#define MIRRED_TAB_MASK 7
	33	static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
	34	static u32 mirred_idx_gen;
1da177e4	35	static DEFINE_RWLOCK(mirred_lock);
3b87956e	36	static LIST_HEAD(mirred_list);
1da177e4	37
e9ce1cd3 DM	38	static struct tcf_hashinfo mirred_hash_info = {
	39	.htab = tcf_mirred_ht,
	40	.hmask = MIRRED_TAB_MASK,
	41	.lock = &mirred_lock,
	42	};
1da177e4	43
cc7ec456	44	static int tcf_mirred_release(struct tcf_mirred *m, int bind)
1da177e4	45	{
e9ce1cd3	46	if (m) {
1da177e4	47	if (bind)
e9ce1cd3 DM	48	m->tcf_bindcnt--;
e9ce1cd3 DM	49	m->tcf_refcnt--;
cc7ec456	50	if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
3b87956e	51	list_del(&m->tcfm_list);
	52	if (m->tcfm_dev)
	53	dev_put(m->tcfm_dev);
e9ce1cd3	54	tcf_hash_destroy(&m->common, &mirred_hash_info);
1da177e4 LT	55	return 1;
	56	}
	57	}
	58	return 0;
	59	}
	60
53b2bf3f PM	61	static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
	62	[TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
	63	};
	64
7ba699c6	65	static int tcf_mirred_init(struct nlattr nla, struct nlattr est,
e9ce1cd3	66	struct tc_action *a, int ovr, int bind)
1da177e4	67	{
7ba699c6	68	struct nlattr *tb[TCA_MIRRED_MAX + 1];
1da177e4	69	struct tc_mirred *parm;
e9ce1cd3 DM	70	struct tcf_mirred *m;
e9ce1cd3 DM	71	struct tcf_common *pc;
b76965e0 CG	72	struct net_device *dev;
b76965e0 CG	73	int ret, ok_push = 0;
1da177e4	74
cee63723	75	if (nla == NULL)
1da177e4	76	return -EINVAL;
b76965e0 CG	77	ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
	78	if (ret < 0)
	79	return ret;
53b2bf3f	80	if (tb[TCA_MIRRED_PARMS] == NULL)
1da177e4	81	return -EINVAL;
7ba699c6	82	parm = nla_data(tb[TCA_MIRRED_PARMS]);
b76965e0 CG	83	switch (parm->eaction) {
	84	case TCA_EGRESS_MIRROR:
	85	case TCA_EGRESS_REDIR:
	86	break;
	87	default:
	88	return -EINVAL;
	89	}
1da177e4	90	if (parm->ifindex) {
881d966b	91	dev = __dev_get_by_index(&init_net, parm->ifindex);
1da177e4 LT	92	if (dev == NULL)
	93	return -ENODEV;
	94	switch (dev->type) {
b76965e0 CG	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;
1da177e4	106	}
b76965e0 CG	107	} else {
b76965e0 CG	108	dev = NULL;
1da177e4 LT	109	}
1da177e4 LT	110
e9ce1cd3 DM	111	pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
e9ce1cd3 DM	112	if (!pc) {
b76965e0	113	if (dev == NULL)
1da177e4	114	return -EINVAL;
e9ce1cd3 DM	115	pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
e9ce1cd3 DM	116	&mirred_idx_gen, &mirred_hash_info);
0e991ec6	117	if (IS_ERR(pc))
b76965e0	118	return PTR_ERR(pc);
1da177e4 LT	119	ret = ACT_P_CREATED;
	120	} else {
	121	if (!ovr) {
e9ce1cd3	122	tcf_mirred_release(to_mirred(pc), bind);
1da177e4 LT	123	return -EEXIST;
	124	}
	125	}
e9ce1cd3	126	m = to_mirred(pc);
1da177e4	127
e9ce1cd3 DM	128	spin_lock_bh(&m->tcf_lock);
	129	m->tcf_action = parm->action;
	130	m->tcfm_eaction = parm->eaction;
b76965e0	131	if (dev != NULL) {
e9ce1cd3	132	m->tcfm_ifindex = parm->ifindex;
1da177e4	133	if (ret != ACT_P_CREATED)
e9ce1cd3	134	dev_put(m->tcfm_dev);
1da177e4	135	dev_hold(dev);
b76965e0	136	m->tcfm_dev = dev;
e9ce1cd3	137	m->tcfm_ok_push = ok_push;
1da177e4	138	}
e9ce1cd3	139	spin_unlock_bh(&m->tcf_lock);
3b87956e	140	if (ret == ACT_P_CREATED) {
3b87956e	141	list_add(&m->tcfm_list, &mirred_list);
e9ce1cd3	142	tcf_hash_insert(pc, &mirred_hash_info);
3b87956e	143	}
1da177e4	144
1da177e4 LT	145	return ret;
	146	}
	147
e9ce1cd3	148	static int tcf_mirred_cleanup(struct tc_action *a, int bind)
1da177e4	149	{
e9ce1cd3	150	struct tcf_mirred *m = a->priv;
1da177e4	151
e9ce1cd3 DM	152	if (m)
e9ce1cd3 DM	153	return tcf_mirred_release(m, bind);
1da177e4 LT	154	return 0;
	155	}
	156
dc7f9f6e	157	static int tcf_mirred(struct sk_buff skb, const struct tc_action a,
e9ce1cd3	158	struct tcf_result *res)
1da177e4	159	{
e9ce1cd3	160	struct tcf_mirred *m = a->priv;
1da177e4	161	struct net_device *dev;
feed1f17 CG	162	struct sk_buff *skb2;
	163	u32 at;
	164	int retval, err = 1;
1da177e4	165
e9ce1cd3	166	spin_lock(&m->tcf_lock);
e9ce1cd3	167	m->tcf_tm.lastuse = jiffies;
bfe0d029	168	bstats_update(&m->tcf_bstats, skb);
1da177e4	169
feed1f17	170	dev = m->tcfm_dev;
3b87956e	171	if (!dev) {
	172	printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
	173	goto out;
	174	}
	175
feed1f17	176	if (!(dev->flags & IFF_UP)) {
e87cc472 JP	177	net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
e87cc472 JP	178	dev->name);
feed1f17	179	goto out;
1da177e4 LT	180	}
1da177e4 LT	181
210d6de7 CG	182	at = G_TC_AT(skb->tc_verd);
210d6de7 CG	183	skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
1da177e4	184	if (skb2 == NULL)
feed1f17	185	goto out;
1da177e4	186
feed1f17	187	if (!(at & AT_EGRESS)) {
e9ce1cd3	188	if (m->tcfm_ok_push)
1da177e4	189	skb_push(skb2, skb2->dev->hard_header_len);
feed1f17	190	}
1da177e4 LT	191
1da177e4 LT	192	/* mirror is always swallowed */
e9ce1cd3	193	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
1da177e4 LT	194	skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
1da177e4 LT	195
8964be4a	196	skb2->skb_iif = skb->dev->ifindex;
210d6de7	197	skb2->dev = dev;
8919bc13	198	err = dev_queue_xmit(skb2);
feed1f17 CG	199
	200	out:
	201	if (err) {
	202	m->tcf_qstats.overlimits++;
16c0b164 JW	203	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
	204	retval = TC_ACT_SHOT;
	205	else
	206	retval = m->tcf_action;
	207	} else
feed1f17	208	retval = m->tcf_action;
e9ce1cd3	209	spin_unlock(&m->tcf_lock);
feed1f17 CG	210
feed1f17 CG	211	return retval;
1da177e4 LT	212	}
1da177e4 LT	213
e9ce1cd3	214	static int tcf_mirred_dump(struct sk_buff skb, struct tc_action a, int bind, int ref)
1da177e4	215	{
27a884dc	216	unsigned char *b = skb_tail_pointer(skb);
e9ce1cd3	217	struct tcf_mirred *m = a->priv;
1c40be12 ED	218	struct tc_mirred opt = {
	219	.index = m->tcf_index,
	220	.action = m->tcf_action,
	221	.refcnt = m->tcf_refcnt - ref,
	222	.bindcnt = m->tcf_bindcnt - bind,
	223	.eaction = m->tcfm_eaction,
	224	.ifindex = m->tcfm_ifindex,
	225	};
1da177e4 LT	226	struct tcf_t t;
1da177e4 LT	227
1b34ec43 DM	228	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
1b34ec43 DM	229	goto nla_put_failure;
e9ce1cd3 DM	230	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
	231	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
	232	t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
1b34ec43 DM	233	if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
1b34ec43 DM	234	goto nla_put_failure;
1da177e4 LT	235	return skb->len;
1da177e4 LT	236
7ba699c6	237	nla_put_failure:
dc5fc579	238	nlmsg_trim(skb, b);
1da177e4 LT	239	return -1;
	240	}
	241
3b87956e	242	static int mirred_device_event(struct notifier_block *unused,
	243	unsigned long event, void *ptr)
	244	{
	245	struct net_device *dev = ptr;
	246	struct tcf_mirred *m;
	247
	248	if (event == NETDEV_UNREGISTER)
	249	list_for_each_entry(m, &mirred_list, tcfm_list) {
	250	if (m->tcfm_dev == dev) {
	251	dev_put(dev);
	252	m->tcfm_dev = NULL;
	253	}
	254	}
	255
	256	return NOTIFY_DONE;
	257	}
	258
	259	static struct notifier_block mirred_device_notifier = {
	260	.notifier_call = mirred_device_event,
	261	};
	262
	263
1da177e4 LT	264	static struct tc_action_ops act_mirred_ops = {
1da177e4 LT	265	.kind = "mirred",
e9ce1cd3	266	.hinfo = &mirred_hash_info,
1da177e4 LT	267	.type = TCA_ACT_MIRRED,
	268	.capab = TCA_CAP_NONE,
	269	.owner = THIS_MODULE,
	270	.act = tcf_mirred,
	271	.dump = tcf_mirred_dump,
	272	.cleanup = tcf_mirred_cleanup,
	273	.lookup = tcf_hash_search,
	274	.init = tcf_mirred_init,
	275	.walk = tcf_generic_walker
	276	};
	277
	278	MODULE_AUTHOR("Jamal Hadi Salim(2002)");
	279	MODULE_DESCRIPTION("Device Mirror/redirect actions");
	280	MODULE_LICENSE("GPL");
	281
e9ce1cd3	282	static int __init mirred_init_module(void)
1da177e4	283	{
3b87956e	284	int err = register_netdevice_notifier(&mirred_device_notifier);
	285	if (err)
	286	return err;
	287
6ff9c364	288	pr_info("Mirror/redirect action on\n");
1da177e4 LT	289	return tcf_register_action(&act_mirred_ops);
	290	}
	291
e9ce1cd3	292	static void __exit mirred_cleanup_module(void)
1da177e4	293	{
3b87956e	294	unregister_netdevice_notifier(&mirred_device_notifier);
1da177e4 LT	295	tcf_unregister_action(&act_mirred_ops);
	296	}
	297
	298	module_init(mirred_init_module);
	299	module_exit(mirred_cleanup_module);