300 lines
6.8 KiB
C
300 lines
6.8 KiB
C
/*
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* net/sched/mirred.c packet mirroring and redirect actions
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Jamal Hadi Salim (2002-4)
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*
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* TODO: Add ingress support (and socket redirect support)
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*
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/gfp.h>
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#include <net/net_namespace.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <linux/tc_act/tc_mirred.h>
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#include <net/tc_act/tc_mirred.h>
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#include <linux/if_arp.h>
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#define MIRRED_TAB_MASK 7
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static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
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static u32 mirred_idx_gen;
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static DEFINE_RWLOCK(mirred_lock);
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static LIST_HEAD(mirred_list);
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static struct tcf_hashinfo mirred_hash_info = {
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.htab = tcf_mirred_ht,
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.hmask = MIRRED_TAB_MASK,
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.lock = &mirred_lock,
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};
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static int tcf_mirred_release(struct tcf_mirred *m, int bind)
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{
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if (m) {
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if (bind)
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m->tcf_bindcnt--;
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m->tcf_refcnt--;
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if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
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list_del(&m->tcfm_list);
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if (m->tcfm_dev)
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dev_put(m->tcfm_dev);
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tcf_hash_destroy(&m->common, &mirred_hash_info);
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return 1;
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}
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}
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return 0;
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}
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static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
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[TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
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};
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static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
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struct tc_action *a, int ovr, int bind)
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{
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struct nlattr *tb[TCA_MIRRED_MAX + 1];
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struct tc_mirred *parm;
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struct tcf_mirred *m;
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struct tcf_common *pc;
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struct net_device *dev;
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int ret, ok_push = 0;
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if (nla == NULL)
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return -EINVAL;
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ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
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if (ret < 0)
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return ret;
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if (tb[TCA_MIRRED_PARMS] == NULL)
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return -EINVAL;
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parm = nla_data(tb[TCA_MIRRED_PARMS]);
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switch (parm->eaction) {
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case TCA_EGRESS_MIRROR:
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case TCA_EGRESS_REDIR:
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break;
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default:
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return -EINVAL;
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}
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if (parm->ifindex) {
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dev = __dev_get_by_index(&init_net, parm->ifindex);
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if (dev == NULL)
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return -ENODEV;
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switch (dev->type) {
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case ARPHRD_TUNNEL:
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case ARPHRD_TUNNEL6:
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case ARPHRD_SIT:
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case ARPHRD_IPGRE:
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case ARPHRD_VOID:
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case ARPHRD_NONE:
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ok_push = 0;
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break;
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default:
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ok_push = 1;
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break;
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}
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} else {
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dev = NULL;
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}
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pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
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if (!pc) {
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if (dev == NULL)
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return -EINVAL;
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pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
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&mirred_idx_gen, &mirred_hash_info);
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if (IS_ERR(pc))
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return PTR_ERR(pc);
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ret = ACT_P_CREATED;
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} else {
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if (!ovr) {
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tcf_mirred_release(to_mirred(pc), bind);
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return -EEXIST;
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}
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}
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m = to_mirred(pc);
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spin_lock_bh(&m->tcf_lock);
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m->tcf_action = parm->action;
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m->tcfm_eaction = parm->eaction;
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if (dev != NULL) {
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m->tcfm_ifindex = parm->ifindex;
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if (ret != ACT_P_CREATED)
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dev_put(m->tcfm_dev);
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dev_hold(dev);
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m->tcfm_dev = dev;
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m->tcfm_ok_push = ok_push;
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}
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spin_unlock_bh(&m->tcf_lock);
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if (ret == ACT_P_CREATED) {
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list_add(&m->tcfm_list, &mirred_list);
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tcf_hash_insert(pc, &mirred_hash_info);
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}
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return ret;
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}
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static int tcf_mirred_cleanup(struct tc_action *a, int bind)
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{
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struct tcf_mirred *m = a->priv;
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if (m)
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return tcf_mirred_release(m, bind);
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return 0;
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}
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static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
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struct tcf_result *res)
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{
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struct tcf_mirred *m = a->priv;
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struct net_device *dev;
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struct sk_buff *skb2;
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u32 at;
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int retval, err = 1;
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spin_lock(&m->tcf_lock);
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m->tcf_tm.lastuse = jiffies;
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bstats_update(&m->tcf_bstats, skb);
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dev = m->tcfm_dev;
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if (!dev) {
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printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
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goto out;
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}
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if (!(dev->flags & IFF_UP)) {
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if (net_ratelimit())
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pr_notice("tc mirred to Houston: device %s is down\n",
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dev->name);
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goto out;
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}
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at = G_TC_AT(skb->tc_verd);
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skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
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if (skb2 == NULL)
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goto out;
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if (!(at & AT_EGRESS)) {
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if (m->tcfm_ok_push)
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skb_push(skb2, skb2->dev->hard_header_len);
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}
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/* mirror is always swallowed */
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if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
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skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
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skb2->skb_iif = skb->dev->ifindex;
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skb2->dev = dev;
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err = dev_queue_xmit(skb2);
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out:
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if (err) {
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m->tcf_qstats.overlimits++;
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/* should we be asking for packet to be dropped?
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* may make sense for redirect case only
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*/
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retval = TC_ACT_SHOT;
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} else {
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retval = m->tcf_action;
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}
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spin_unlock(&m->tcf_lock);
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return retval;
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}
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static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
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{
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unsigned char *b = skb_tail_pointer(skb);
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struct tcf_mirred *m = a->priv;
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struct tc_mirred opt = {
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.index = m->tcf_index,
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.action = m->tcf_action,
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.refcnt = m->tcf_refcnt - ref,
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.bindcnt = m->tcf_bindcnt - bind,
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.eaction = m->tcfm_eaction,
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.ifindex = m->tcfm_ifindex,
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};
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struct tcf_t t;
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NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
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t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
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t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
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t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
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NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
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return skb->len;
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nla_put_failure:
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nlmsg_trim(skb, b);
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return -1;
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}
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static int mirred_device_event(struct notifier_block *unused,
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unsigned long event, void *ptr)
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{
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struct net_device *dev = ptr;
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struct tcf_mirred *m;
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if (event == NETDEV_UNREGISTER)
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list_for_each_entry(m, &mirred_list, tcfm_list) {
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if (m->tcfm_dev == dev) {
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dev_put(dev);
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m->tcfm_dev = NULL;
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}
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}
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return NOTIFY_DONE;
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}
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static struct notifier_block mirred_device_notifier = {
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.notifier_call = mirred_device_event,
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};
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static struct tc_action_ops act_mirred_ops = {
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.kind = "mirred",
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.hinfo = &mirred_hash_info,
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.type = TCA_ACT_MIRRED,
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.capab = TCA_CAP_NONE,
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.owner = THIS_MODULE,
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.act = tcf_mirred,
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.dump = tcf_mirred_dump,
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.cleanup = tcf_mirred_cleanup,
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.lookup = tcf_hash_search,
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.init = tcf_mirred_init,
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.walk = tcf_generic_walker
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};
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MODULE_AUTHOR("Jamal Hadi Salim(2002)");
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MODULE_DESCRIPTION("Device Mirror/redirect actions");
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MODULE_LICENSE("GPL");
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static int __init mirred_init_module(void)
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{
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int err = register_netdevice_notifier(&mirred_device_notifier);
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if (err)
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return err;
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pr_info("Mirror/redirect action on\n");
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return tcf_register_action(&act_mirred_ops);
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}
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static void __exit mirred_cleanup_module(void)
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{
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unregister_netdevice_notifier(&mirred_device_notifier);
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tcf_unregister_action(&act_mirred_ops);
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}
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module_init(mirred_init_module);
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module_exit(mirred_cleanup_module);
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