[net-next-2.6.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 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())
			pr_notice("tc 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)
{
	pr_info("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>
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 LT	35	static DEFINE_RWLOCK(mirred_lock);
1da177e4 LT	36
e9ce1cd3 DM	37	static struct tcf_hashinfo mirred_hash_info = {
	38	.htab = tcf_mirred_ht,
	39	.hmask = MIRRED_TAB_MASK,
	40	.lock = &mirred_lock,
	41	};
1da177e4	42
e9ce1cd3	43	static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
1da177e4	44	{
e9ce1cd3	45	if (m) {
1da177e4	46	if (bind)
e9ce1cd3 DM	47	m->tcf_bindcnt--;
	48	m->tcf_refcnt--;
	49	if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
	50	dev_put(m->tcfm_dev);
	51	tcf_hash_destroy(&m->common, &mirred_hash_info);
1da177e4 LT	52	return 1;
	53	}
	54	}
	55	return 0;
	56	}
	57
53b2bf3f PM	58	static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
	59	[TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
	60	};
	61
7ba699c6	62	static int tcf_mirred_init(struct nlattr nla, struct nlattr est,
e9ce1cd3	63	struct tc_action *a, int ovr, int bind)
1da177e4	64	{
7ba699c6	65	struct nlattr *tb[TCA_MIRRED_MAX + 1];
1da177e4	66	struct tc_mirred *parm;
e9ce1cd3 DM	67	struct tcf_mirred *m;
e9ce1cd3 DM	68	struct tcf_common *pc;
b76965e0 CG	69	struct net_device *dev;
b76965e0 CG	70	int ret, ok_push = 0;
1da177e4	71
cee63723	72	if (nla == NULL)
1da177e4	73	return -EINVAL;
b76965e0 CG	74	ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
	75	if (ret < 0)
	76	return ret;
53b2bf3f	77	if (tb[TCA_MIRRED_PARMS] == NULL)
1da177e4	78	return -EINVAL;
7ba699c6	79	parm = nla_data(tb[TCA_MIRRED_PARMS]);
b76965e0 CG	80	switch (parm->eaction) {
	81	case TCA_EGRESS_MIRROR:
	82	case TCA_EGRESS_REDIR:
	83	break;
	84	default:
	85	return -EINVAL;
	86	}
1da177e4	87	if (parm->ifindex) {
881d966b	88	dev = __dev_get_by_index(&init_net, parm->ifindex);
1da177e4 LT	89	if (dev == NULL)
	90	return -ENODEV;
	91	switch (dev->type) {
b76965e0 CG	92	case ARPHRD_TUNNEL:
	93	case ARPHRD_TUNNEL6:
	94	case ARPHRD_SIT:
	95	case ARPHRD_IPGRE:
	96	case ARPHRD_VOID:
	97	case ARPHRD_NONE:
	98	ok_push = 0;
	99	break;
	100	default:
	101	ok_push = 1;
	102	break;
1da177e4	103	}
b76965e0 CG	104	} else {
b76965e0 CG	105	dev = NULL;
1da177e4 LT	106	}
1da177e4 LT	107
e9ce1cd3 DM	108	pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
e9ce1cd3 DM	109	if (!pc) {
b76965e0	110	if (dev == NULL)
1da177e4	111	return -EINVAL;
e9ce1cd3 DM	112	pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
e9ce1cd3 DM	113	&mirred_idx_gen, &mirred_hash_info);
0e991ec6	114	if (IS_ERR(pc))
b76965e0	115	return PTR_ERR(pc);
1da177e4 LT	116	ret = ACT_P_CREATED;
	117	} else {
	118	if (!ovr) {
e9ce1cd3	119	tcf_mirred_release(to_mirred(pc), bind);
1da177e4 LT	120	return -EEXIST;
	121	}
	122	}
e9ce1cd3	123	m = to_mirred(pc);
1da177e4	124
e9ce1cd3 DM	125	spin_lock_bh(&m->tcf_lock);
	126	m->tcf_action = parm->action;
	127	m->tcfm_eaction = parm->eaction;
b76965e0	128	if (dev != NULL) {
e9ce1cd3	129	m->tcfm_ifindex = parm->ifindex;
1da177e4	130	if (ret != ACT_P_CREATED)
e9ce1cd3	131	dev_put(m->tcfm_dev);
1da177e4	132	dev_hold(dev);
b76965e0	133	m->tcfm_dev = dev;
e9ce1cd3	134	m->tcfm_ok_push = ok_push;
1da177e4	135	}
e9ce1cd3	136	spin_unlock_bh(&m->tcf_lock);
1da177e4	137	if (ret == ACT_P_CREATED)
e9ce1cd3	138	tcf_hash_insert(pc, &mirred_hash_info);
1da177e4	139
1da177e4 LT	140	return ret;
	141	}
	142
e9ce1cd3	143	static int tcf_mirred_cleanup(struct tc_action *a, int bind)
1da177e4	144	{
e9ce1cd3	145	struct tcf_mirred *m = a->priv;
1da177e4	146
e9ce1cd3 DM	147	if (m)
e9ce1cd3 DM	148	return tcf_mirred_release(m, bind);
1da177e4 LT	149	return 0;
	150	}
	151
e9ce1cd3 DM	152	static int tcf_mirred(struct sk_buff skb, struct tc_action a,
e9ce1cd3 DM	153	struct tcf_result *res)
1da177e4	154	{
e9ce1cd3	155	struct tcf_mirred *m = a->priv;
1da177e4	156	struct net_device *dev;
feed1f17 CG	157	struct sk_buff *skb2;
	158	u32 at;
	159	int retval, err = 1;
1da177e4	160
e9ce1cd3	161	spin_lock(&m->tcf_lock);
e9ce1cd3	162	m->tcf_tm.lastuse = jiffies;
1da177e4	163
feed1f17 CG	164	dev = m->tcfm_dev;
feed1f17 CG	165	if (!(dev->flags & IFF_UP)) {
1da177e4	166	if (net_ratelimit())
6ff9c364	167	pr_notice("tc mirred to Houston: device %s is gone!\n",
6ff9c364	168	dev->name);
feed1f17	169	goto out;
1da177e4 LT	170	}
1da177e4 LT	171
a057ae3c	172	skb2 = skb_act_clone(skb, GFP_ATOMIC);
1da177e4	173	if (skb2 == NULL)
feed1f17	174	goto out;
1da177e4	175
0abf77e5	176	m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
e9ce1cd3	177	m->tcf_bstats.packets++;
feed1f17 CG	178	at = G_TC_AT(skb->tc_verd);
feed1f17 CG	179	if (!(at & AT_EGRESS)) {
e9ce1cd3	180	if (m->tcfm_ok_push)
1da177e4	181	skb_push(skb2, skb2->dev->hard_header_len);
feed1f17	182	}
1da177e4 LT	183
1da177e4 LT	184	/* mirror is always swallowed */
e9ce1cd3	185	if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
1da177e4 LT	186	skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
	187
	188	skb2->dev = dev;
8964be4a	189	skb2->skb_iif = skb->dev->ifindex;
1da177e4	190	dev_queue_xmit(skb2);
feed1f17 CG	191	err = 0;
	192
	193	out:
	194	if (err) {
	195	m->tcf_qstats.overlimits++;
	196	m->tcf_bstats.bytes += qdisc_pkt_len(skb);
	197	m->tcf_bstats.packets++;
	198	/* should we be asking for packet to be dropped?
	199	* may make sense for redirect case only
	200	*/
	201	retval = TC_ACT_SHOT;
	202	} else {
	203	retval = m->tcf_action;
	204	}
e9ce1cd3	205	spin_unlock(&m->tcf_lock);
feed1f17 CG	206
feed1f17 CG	207	return retval;
1da177e4 LT	208	}
1da177e4 LT	209
e9ce1cd3	210	static int tcf_mirred_dump(struct sk_buff skb, struct tc_action a, int bind, int ref)
1da177e4	211	{
27a884dc	212	unsigned char *b = skb_tail_pointer(skb);
e9ce1cd3	213	struct tcf_mirred *m = a->priv;
1da177e4	214	struct tc_mirred opt;
1da177e4 LT	215	struct tcf_t t;
1da177e4 LT	216
e9ce1cd3 DM	217	opt.index = m->tcf_index;
	218	opt.action = m->tcf_action;
	219	opt.refcnt = m->tcf_refcnt - ref;
	220	opt.bindcnt = m->tcf_bindcnt - bind;
	221	opt.eaction = m->tcfm_eaction;
	222	opt.ifindex = m->tcfm_ifindex;
7ba699c6	223	NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
e9ce1cd3 DM	224	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
	225	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
	226	t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
7ba699c6	227	NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
1da177e4 LT	228	return skb->len;
1da177e4 LT	229
7ba699c6	230	nla_put_failure:
dc5fc579	231	nlmsg_trim(skb, b);
1da177e4 LT	232	return -1;
	233	}
	234
	235	static struct tc_action_ops act_mirred_ops = {
	236	.kind = "mirred",
e9ce1cd3	237	.hinfo = &mirred_hash_info,
1da177e4 LT	238	.type = TCA_ACT_MIRRED,
	239	.capab = TCA_CAP_NONE,
	240	.owner = THIS_MODULE,
	241	.act = tcf_mirred,
	242	.dump = tcf_mirred_dump,
	243	.cleanup = tcf_mirred_cleanup,
	244	.lookup = tcf_hash_search,
	245	.init = tcf_mirred_init,
	246	.walk = tcf_generic_walker
	247	};
	248
	249	MODULE_AUTHOR("Jamal Hadi Salim(2002)");
	250	MODULE_DESCRIPTION("Device Mirror/redirect actions");
	251	MODULE_LICENSE("GPL");
	252
e9ce1cd3	253	static int __init mirred_init_module(void)
1da177e4	254	{
6ff9c364	255	pr_info("Mirror/redirect action on\n");
1da177e4 LT	256	return tcf_register_action(&act_mirred_ops);
	257	}
	258
e9ce1cd3	259	static void __exit mirred_cleanup_module(void)
1da177e4 LT	260	{
	261	tcf_unregister_action(&act_mirred_ops);
	262	}
	263
	264	module_init(mirred_init_module);
	265	module_exit(mirred_cleanup_module);