![Davide Caratti](/assets/img/avatar_default.png)
use nla_strlcpy() to avoid copying data beyond the length of TCA_DEF_DATA
netlink attribute, in case it is less than SIMP_MAX_DATA and it does not
end with '\0' character.
v2: fix errors in the commit message, thanks Hangbin Liu
Fixes: fa1b1cff3d
("net_cls_act: Make act_simple use of netlink policy.")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
237 lines
5.7 KiB
C
237 lines
5.7 KiB
C
/*
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* net/sched/act_simple.c Simple example of an action
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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 (2005-8)
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*
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#define TCA_ACT_SIMP 22
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#include <linux/tc_act/tc_defact.h>
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#include <net/tc_act/tc_defact.h>
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static unsigned int simp_net_id;
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static struct tc_action_ops act_simp_ops;
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#define SIMP_MAX_DATA 32
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static int tcf_simp(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_defact *d = to_defact(a);
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spin_lock(&d->tcf_lock);
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tcf_lastuse_update(&d->tcf_tm);
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bstats_update(&d->tcf_bstats, skb);
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/* print policy string followed by _ then packet count
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* Example if this was the 3rd packet and the string was "hello"
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* then it would look like "hello_3" (without quotes)
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*/
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pr_info("simple: %s_%d\n",
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(char *)d->tcfd_defdata, d->tcf_bstats.packets);
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spin_unlock(&d->tcf_lock);
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return d->tcf_action;
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}
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static void tcf_simp_release(struct tc_action *a)
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{
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struct tcf_defact *d = to_defact(a);
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kfree(d->tcfd_defdata);
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}
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static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata)
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{
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d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
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if (unlikely(!d->tcfd_defdata))
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return -ENOMEM;
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nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
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return 0;
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}
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static void reset_policy(struct tcf_defact *d, const struct nlattr *defdata,
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struct tc_defact *p)
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{
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spin_lock_bh(&d->tcf_lock);
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d->tcf_action = p->action;
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memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
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nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
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spin_unlock_bh(&d->tcf_lock);
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}
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static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
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[TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) },
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[TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA },
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};
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static int tcf_simp_init(struct net *net, struct nlattr *nla,
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struct nlattr *est, struct tc_action **a,
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int ovr, int bind, struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, simp_net_id);
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struct nlattr *tb[TCA_DEF_MAX + 1];
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struct tc_defact *parm;
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struct tcf_defact *d;
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bool exists = false;
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int ret = 0, err;
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if (nla == NULL)
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return -EINVAL;
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err = nla_parse_nested(tb, TCA_DEF_MAX, nla, simple_policy, NULL);
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if (err < 0)
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return err;
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if (tb[TCA_DEF_PARMS] == NULL)
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return -EINVAL;
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parm = nla_data(tb[TCA_DEF_PARMS]);
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exists = tcf_idr_check(tn, parm->index, a, bind);
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if (exists && bind)
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return 0;
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if (tb[TCA_DEF_DATA] == NULL) {
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if (exists)
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tcf_idr_release(*a, bind);
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return -EINVAL;
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}
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if (!exists) {
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ret = tcf_idr_create(tn, parm->index, est, a,
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&act_simp_ops, bind, false);
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if (ret)
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return ret;
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d = to_defact(*a);
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ret = alloc_defdata(d, tb[TCA_DEF_DATA]);
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if (ret < 0) {
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tcf_idr_release(*a, bind);
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return ret;
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}
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d->tcf_action = parm->action;
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ret = ACT_P_CREATED;
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} else {
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d = to_defact(*a);
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tcf_idr_release(*a, bind);
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if (!ovr)
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return -EEXIST;
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reset_policy(d, tb[TCA_DEF_DATA], parm);
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}
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if (ret == ACT_P_CREATED)
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tcf_idr_insert(tn, *a);
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return ret;
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}
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static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
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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_defact *d = to_defact(a);
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struct tc_defact opt = {
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.index = d->tcf_index,
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.refcnt = d->tcf_refcnt - ref,
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.bindcnt = d->tcf_bindcnt - bind,
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.action = d->tcf_action,
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};
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struct tcf_t t;
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if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
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nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
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goto nla_put_failure;
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tcf_tm_dump(&t, &d->tcf_tm);
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if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD))
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goto nla_put_failure;
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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 tcf_simp_walker(struct net *net, struct sk_buff *skb,
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struct netlink_callback *cb, int type,
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const struct tc_action_ops *ops,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, simp_net_id);
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return tcf_generic_walker(tn, skb, cb, type, ops, extack);
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}
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static int tcf_simp_search(struct net *net, struct tc_action **a, u32 index,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, simp_net_id);
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return tcf_idr_search(tn, a, index);
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}
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static struct tc_action_ops act_simp_ops = {
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.kind = "simple",
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.type = TCA_ACT_SIMP,
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.owner = THIS_MODULE,
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.act = tcf_simp,
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.dump = tcf_simp_dump,
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.cleanup = tcf_simp_release,
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.init = tcf_simp_init,
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.walk = tcf_simp_walker,
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.lookup = tcf_simp_search,
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.size = sizeof(struct tcf_defact),
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};
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static __net_init int simp_init_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, simp_net_id);
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return tc_action_net_init(tn, &act_simp_ops);
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}
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static void __net_exit simp_exit_net(struct list_head *net_list)
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{
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tc_action_net_exit(net_list, simp_net_id);
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}
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static struct pernet_operations simp_net_ops = {
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.init = simp_init_net,
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.exit_batch = simp_exit_net,
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.id = &simp_net_id,
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.size = sizeof(struct tc_action_net),
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};
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MODULE_AUTHOR("Jamal Hadi Salim(2005)");
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MODULE_DESCRIPTION("Simple example action");
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MODULE_LICENSE("GPL");
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static int __init simp_init_module(void)
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{
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int ret = tcf_register_action(&act_simp_ops, &simp_net_ops);
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if (!ret)
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pr_info("Simple TC action Loaded\n");
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return ret;
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}
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static void __exit simp_cleanup_module(void)
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{
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tcf_unregister_action(&act_simp_ops, &simp_net_ops);
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}
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module_init(simp_init_module);
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module_exit(simp_cleanup_module);
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