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/*
* 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;
}
at = G_TC_AT(skb->tc_verd);
skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
if (skb2 == NULL)
goto out;
m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
m->tcf_bstats.packets++;
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;
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);
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