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

static inline 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) {
			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)
		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, 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;

	dev = m->tcfm_dev;
	if (!(dev->flags & IFF_UP)) {
		if (net_ratelimit())
			printk("mirred to Houston: device %s is gone!\n",
			       dev->name);
		goto out;
	}

	skb2 = skb_act_clone(skb, GFP_ATOMIC);
	if (skb2 == NULL)
		goto out;

	m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
	m->tcf_bstats.packets++;
	at = G_TC_AT(skb->tc_verd);
	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->dev = dev;
	skb2->skb_iif = skb->dev->ifindex;
	dev_queue_xmit(skb2);
	err = 0;

out:
	if (err) {
		m->tcf_qstats.overlimits++;
		m->tcf_bstats.bytes += qdisc_pkt_len(skb);
		m->tcf_bstats.packets++;
		/* should we be asking for packet to be dropped?
		 * may make sense for redirect case only
		 */
		retval = TC_ACT_SHOT;
	} 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;
	struct tcf_t t;

	opt.index = m->tcf_index;
	opt.action = m->tcf_action;
	opt.refcnt = m->tcf_refcnt - ref;
	opt.bindcnt = m->tcf_bindcnt - bind;
	opt.eaction = m->tcfm_eaction;
	opt.ifindex = m->tcfm_ifindex;
	NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
	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);
	NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
	return skb->len;

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

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)
{
	printk("Mirror/redirect action on\n");
	return tcf_register_action(&act_mirred_ops);
}

static void __exit mirred_cleanup_module(void)
{
	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>
881d966b	23	#include <net/net_namespace.h>
dc5fc579	24	#include <net/netlink.h>
1da177e4 LT	25	#include <net/pkt_sched.h>
	26	#include <linux/tc_act/tc_mirred.h>
	27	#include <net/tc_act/tc_mirred.h>
	28
1da177e4 LT	29	#include <linux/if_arp.h>
1da177e4 LT	30
e9ce1cd3 DM	31	#define MIRRED_TAB_MASK 7
	32	static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
	33	static u32 mirred_idx_gen;
1da177e4 LT	34	static DEFINE_RWLOCK(mirred_lock);
1da177e4 LT	35
e9ce1cd3 DM	36	static struct tcf_hashinfo mirred_hash_info = {
	37	.htab = tcf_mirred_ht,
	38	.hmask = MIRRED_TAB_MASK,
	39	.lock = &mirred_lock,
	40	};
1da177e4	41
e9ce1cd3	42	static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
1da177e4	43	{
e9ce1cd3	44	if (m) {
1da177e4	45	if (bind)
e9ce1cd3 DM	46	m->tcf_bindcnt--;
	47	m->tcf_refcnt--;
	48	if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
	49	dev_put(m->tcfm_dev);
	50	tcf_hash_destroy(&m->common, &mirred_hash_info);
1da177e4 LT	51	return 1;
	52	}
	53	}
	54	return 0;
	55	}
	56
53b2bf3f PM	57	static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
	58	[TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
	59	};
	60
7ba699c6	61	static int tcf_mirred_init(struct nlattr nla, struct nlattr est,
e9ce1cd3	62	struct tc_action *a, int ovr, int bind)
1da177e4	63	{
7ba699c6	64	struct nlattr *tb[TCA_MIRRED_MAX + 1];
1da177e4	65	struct tc_mirred *parm;
e9ce1cd3 DM	66	struct tcf_mirred *m;
e9ce1cd3 DM	67	struct tcf_common *pc;
b76965e0 CG	68	struct net_device *dev;
b76965e0 CG	69	int ret, ok_push = 0;
1da177e4	70
cee63723	71	if (nla == NULL)
1da177e4	72	return -EINVAL;
b76965e0 CG	73	ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
	74	if (ret < 0)
	75	return ret;
53b2bf3f	76	if (tb[TCA_MIRRED_PARMS] == NULL)
1da177e4	77	return -EINVAL;
7ba699c6	78	parm = nla_data(tb[TCA_MIRRED_PARMS]);
b76965e0 CG	79	switch (parm->eaction) {
	80	case TCA_EGRESS_MIRROR:
	81	case TCA_EGRESS_REDIR:
	82	break;
	83	default:
	84	return -EINVAL;
	85	}
1da177e4	86	if (parm->ifindex) {
881d966b	87	dev = __dev_get_by_index(&init_net, parm->ifindex);
1da177e4 LT	88	if (dev == NULL)
	89	return -ENODEV;
	90	switch (dev->type) {
b76965e0 CG	91	case ARPHRD_TUNNEL:
	92	case ARPHRD_TUNNEL6:
	93	case ARPHRD_SIT:
	94	case ARPHRD_IPGRE:
	95	case ARPHRD_VOID:
	96	case ARPHRD_NONE:
	97	ok_push = 0;
	98	break;
	99	default:
	100	ok_push = 1;
	101	break;
1da177e4	102	}
b76965e0 CG	103	} else {
b76965e0 CG	104	dev = NULL;
1da177e4 LT	105	}
1da177e4 LT	106
e9ce1cd3 DM	107	pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
e9ce1cd3 DM	108	if (!pc) {
b76965e0	109	if (dev == NULL)
1da177e4	110	return -EINVAL;
e9ce1cd3 DM	111	pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
e9ce1cd3 DM	112	&mirred_idx_gen, &mirred_hash_info);
0e991ec6	113	if (IS_ERR(pc))
b76965e0	114	return PTR_ERR(pc);
1da177e4 LT	115	ret = ACT_P_CREATED;
	116	} else {
	117	if (!ovr) {
e9ce1cd3	118	tcf_mirred_release(to_mirred(pc), bind);
1da177e4 LT	119	return -EEXIST;
	120	}
	121	}
e9ce1cd3	122	m = to_mirred(pc);
1da177e4	123
e9ce1cd3 DM	124	spin_lock_bh(&m->tcf_lock);
	125	m->tcf_action = parm->action;
	126	m->tcfm_eaction = parm->eaction;
b76965e0	127	if (dev != NULL) {
e9ce1cd3	128	m->tcfm_ifindex = parm->ifindex;
1da177e4	129	if (ret != ACT_P_CREATED)
e9ce1cd3	130	dev_put(m->tcfm_dev);
1da177e4	131	dev_hold(dev);
b76965e0	132	m->tcfm_dev = dev;
e9ce1cd3	133	m->tcfm_ok_push = ok_push;
1da177e4	134	}
e9ce1cd3	135	spin_unlock_bh(&m->tcf_lock);
1da177e4	136	if (ret == ACT_P_CREATED)
e9ce1cd3	137	tcf_hash_insert(pc, &mirred_hash_info);
1da177e4	138
1da177e4 LT	139	return ret;
	140	}
	141
e9ce1cd3	142	static int tcf_mirred_cleanup(struct tc_action *a, int bind)
1da177e4	143	{
e9ce1cd3	144	struct tcf_mirred *m = a->priv;
1da177e4	145
e9ce1cd3 DM	146	if (m)
e9ce1cd3 DM	147	return tcf_mirred_release(m, bind);
1da177e4 LT	148	return 0;
	149	}
	150
e9ce1cd3 DM	151	static int tcf_mirred(struct sk_buff skb, struct tc_action a,
e9ce1cd3 DM	152	struct tcf_result *res)
1da177e4	153	{
e9ce1cd3	154	struct tcf_mirred *m = a->priv;
1da177e4	155	struct net_device *dev;
feed1f17 CG	156	struct sk_buff *skb2;
	157	u32 at;
	158	int retval, err = 1;
1da177e4	159
e9ce1cd3	160	spin_lock(&m->tcf_lock);
e9ce1cd3	161	m->tcf_tm.lastuse = jiffies;
1da177e4	162
feed1f17 CG	163	dev = m->tcfm_dev;
feed1f17 CG	164	if (!(dev->flags & IFF_UP)) {
1da177e4 LT	165	if (net_ratelimit())
	166	printk("mirred to Houston: device %s is gone!\n",
	167	dev->name);
feed1f17	168	goto out;
1da177e4 LT	169	}
1da177e4 LT	170
a057ae3c	171	skb2 = skb_act_clone(skb, GFP_ATOMIC);
1da177e4	172	if (skb2 == NULL)
feed1f17	173	goto out;
1da177e4	174
0abf77e5	175	m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
e9ce1cd3	176	m->tcf_bstats.packets++;
feed1f17 CG	177	at = G_TC_AT(skb->tc_verd);
feed1f17 CG	178	if (!(at & AT_EGRESS)) {
e9ce1cd3	179	if (m->tcfm_ok_push)
1da177e4	180	skb_push(skb2, skb2->dev->hard_header_len);
feed1f17	181	}
1da177e4 LT	182
1da177e4 LT	183	/* mirror is always swallowed */
e9ce1cd3	184	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
1da177e4 LT	185	skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
	186
	187	skb2->dev = dev;
8964be4a	188	skb2->skb_iif = skb->dev->ifindex;
1da177e4	189	dev_queue_xmit(skb2);
feed1f17 CG	190	err = 0;
	191
	192	out:
	193	if (err) {
	194	m->tcf_qstats.overlimits++;
	195	m->tcf_bstats.bytes += qdisc_pkt_len(skb);
	196	m->tcf_bstats.packets++;
	197	/* should we be asking for packet to be dropped?
	198	* may make sense for redirect case only
	199	*/
	200	retval = TC_ACT_SHOT;
	201	} else {
	202	retval = m->tcf_action;
	203	}
e9ce1cd3	204	spin_unlock(&m->tcf_lock);
feed1f17 CG	205
feed1f17 CG	206	return retval;
1da177e4 LT	207	}
1da177e4 LT	208
e9ce1cd3	209	static int tcf_mirred_dump(struct sk_buff skb, struct tc_action a, int bind, int ref)
1da177e4	210	{
27a884dc	211	unsigned char *b = skb_tail_pointer(skb);
e9ce1cd3	212	struct tcf_mirred *m = a->priv;
1da177e4	213	struct tc_mirred opt;
1da177e4 LT	214	struct tcf_t t;
1da177e4 LT	215
e9ce1cd3 DM	216	opt.index = m->tcf_index;
	217	opt.action = m->tcf_action;
	218	opt.refcnt = m->tcf_refcnt - ref;
	219	opt.bindcnt = m->tcf_bindcnt - bind;
	220	opt.eaction = m->tcfm_eaction;
	221	opt.ifindex = m->tcfm_ifindex;
7ba699c6	222	NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
e9ce1cd3 DM	223	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
	224	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
	225	t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
7ba699c6	226	NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
1da177e4 LT	227	return skb->len;
1da177e4 LT	228
7ba699c6	229	nla_put_failure:
dc5fc579	230	nlmsg_trim(skb, b);
1da177e4 LT	231	return -1;
	232	}
	233
	234	static struct tc_action_ops act_mirred_ops = {
	235	.kind = "mirred",
e9ce1cd3	236	.hinfo = &mirred_hash_info,
1da177e4 LT	237	.type = TCA_ACT_MIRRED,
	238	.capab = TCA_CAP_NONE,
	239	.owner = THIS_MODULE,
	240	.act = tcf_mirred,
	241	.dump = tcf_mirred_dump,
	242	.cleanup = tcf_mirred_cleanup,
	243	.lookup = tcf_hash_search,
	244	.init = tcf_mirred_init,
	245	.walk = tcf_generic_walker
	246	};
	247
	248	MODULE_AUTHOR("Jamal Hadi Salim(2002)");
	249	MODULE_DESCRIPTION("Device Mirror/redirect actions");
	250	MODULE_LICENSE("GPL");
	251
e9ce1cd3	252	static int __init mirred_init_module(void)
1da177e4 LT	253	{
	254	printk("Mirror/redirect action on\n");
	255	return tcf_register_action(&act_mirred_ops);
	256	}
	257
e9ce1cd3	258	static void __exit mirred_cleanup_module(void)
1da177e4 LT	259	{
	260	tcf_unregister_action(&act_mirred_ops);
	261	}
	262
	263	module_init(mirred_init_module);
	264	module_exit(mirred_cleanup_module);