- 根目录:
- net
- sched
- act_police.c
/*
* net/sched/act_police.c Input police filter
*
* 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: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
* J Hadi Salim (action changes)
*/
#include <linux/module.h>
#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/init.h>
#include <linux/slab.h>
#include <net/act_api.h>
#include <net/netlink.h>
struct tcf_police {
struct tcf_common common;
int tcfp_result;
u32 tcfp_ewma_rate;
s64 tcfp_burst;
u32 tcfp_mtu;
s64 tcfp_toks;
s64 tcfp_ptoks;
s64 tcfp_mtu_ptoks;
s64 tcfp_t_c;
struct psched_ratecfg rate;
bool rate_present;
struct psched_ratecfg peak;
bool peak_present;
};
#define to_police(pc) \
container_of(pc, struct tcf_police, common)
#define POL_TAB_MASK 15
/* old policer structure from before tc actions */
struct tc_police_compat {
u32 index;
int action;
u32 limit;
u32 burst;
u32 mtu;
struct tc_ratespec rate;
struct tc_ratespec peakrate;
};
/* Each policer is serialized by its individual spinlock */
static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
int type, struct tc_action *a)
{
struct tcf_hashinfo *hinfo = a->ops->hinfo;
struct hlist_head *head;
struct tcf_common *p;
int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
struct nlattr *nest;
spin_lock_bh(&hinfo->lock);
s_i = cb->args[0];
for (i = 0; i < (POL_TAB_MASK + 1); i++) {
head = &hinfo->htab[tcf_hash(i, POL_TAB_MASK)];
hlist_for_each_entry_rcu(p, head, tcfc_head) {
index++;
if (index < s_i)
continue;
a->priv = p;
a->order = index;
nest = nla_nest_start(skb, a->order);
if (nest == NULL)
goto nla_put_failure;
if (type == RTM_DELACTION)
err = tcf_action_dump_1(skb, a, 0, 1);
else
err = tcf_action_dump_1(skb, a, 0, 0);
if (err < 0) {
index--;
nla_nest_cancel(skb, nest);
goto done;
}
nla_nest_end(skb, nest);
n_i++;
}
}
done:
spin_unlock_bh(&hinfo->lock);
if (n_i)
cb->args[0] += n_i;
return n_i;
nla_put_failure:
nla_nest_cancel(skb, nest);
goto done;
}
static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
[TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
[TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
[TCA_POLICE_AVRATE] = { .type = NLA_U32 },
[TCA_POLICE_RESULT] = { .type = NLA_U32 },
};
static int tcf_act_police_locate(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action *a,
int ovr, int bind)
{
unsigned int h;
int ret = 0, err;
struct nlattr *tb[TCA_POLICE_MAX + 1];
struct tc_police *parm;
struct tcf_police *police;
struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
struct tcf_hashinfo *hinfo = a->ops->hinfo;
int size;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
if (err < 0)
return err;
if (tb[TCA_POLICE_TBF] == NULL)
return -EINVAL;
size = nla_len(tb[TCA_POLICE_TBF]);
if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
return -EINVAL;
parm = nla_data(tb[TCA_POLICE_TBF]);
if (parm->index) {
if (tcf_hash_search(a, parm->index)) {
police = to_police(a->priv);
if (bind) {
police->tcf_bindcnt += 1;
police->tcf_refcnt += 1;
return 0;
}
if (ovr)
goto override;
/* not replacing */
return -EEXIST;
}
}
police = kzalloc(sizeof(*police), GFP_KERNEL);
if (police == NULL)
return -ENOMEM;
ret = ACT_P_CREATED;
police->tcf_refcnt = 1;
spin_lock_init(&police->tcf_lock);
if (bind)
police->tcf_bindcnt = 1;
override:
if (parm->rate.rate) {
err = -ENOMEM;
R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
if (R_tab == NULL)
goto failure;
if (parm->peakrate.rate) {
P_tab = qdisc_get_rtab(&parm->peakrate,
tb[TCA_POLICE_PEAKRATE]);
if (P_tab == NULL)
goto failure;
}
}
spin_lock_bh(&police->tcf_lock);
if (est) {
err = gen_replace_estimator(&police->tcf_bstats, NULL,
&police->tcf_rate_est,
&police->tcf_lock, est);
if (err)
goto failure_unlock;
} else if (tb[TCA_POLICE_AVRATE] &&
(ret == ACT_P_CREATED ||
!gen_estimator_active(&police->tcf_bstats,
&police->tcf_rate_est))) {
err = -EINVAL;
goto failure_unlock;
}
/* No failure allowed after this point */
police->tcfp_mtu = parm->mtu;
if (police->tcfp_mtu == 0) {
police->tcfp_mtu = ~0;
if (R_tab)
police->tcfp_mtu = 255 << R_tab->rate.cell_log;
}
if (R_tab) {
police->rate_present = true;
psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
qdisc_put_rtab(R_tab);
} else {
police->rate_present = false;
}
if (P_tab) {
police->peak_present = true;
psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
qdisc_put_rtab(P_tab);
} else {
police->peak_present = false;
}
if (tb[TCA_POLICE_RESULT])
police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
police->tcfp_toks = police->tcfp_burst;
if (police->peak_present) {
police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
police->tcfp_mtu);
police->tcfp_ptoks = police->tcfp_mtu_ptoks;
}
police->tcf_action = parm->action;
if (tb[TCA_POLICE_AVRATE])
police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
spin_unlock_bh(&police->tcf_lock);
if (ret != ACT_P_CREATED)
return ret;
police->tcfp_t_c = ktime_get_ns();
police->tcf_index = parm->index ? parm->index :
tcf_hash_new_index(hinfo);
h = tcf_hash(police->tcf_index, POL_TAB_MASK);
spin_lock_bh(&hinfo->lock);
hlist_add_head(&police->tcf_head, &hinfo->htab[h]);
spin_unlock_bh(&hinfo->lock);
a->priv = police;
return ret;
failure_unlock:
spin_unlock_bh(&police->tcf_lock);
failure:
qdisc_put_rtab(P_tab);
qdisc_put_rtab(R_tab);
if (ret == ACT_P_CREATED)
kfree(police);
return err;
}
static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_police *police = a->priv;
s64 now;
s64 toks;
s64 ptoks = 0;
spin_lock(&police->tcf_lock);
bstats_update(&police->tcf_bstats, skb);
if (police->tcfp_ewma_rate &&
police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
police->tcf_qstats.overlimits++;
if (police->tcf_action == TC_ACT_SHOT)
police->tcf_qstats.drops++;
spin_unlock(&police->tcf_lock);
return police->tcf_action;
}
if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
if (!police->rate_present) {
spin_unlock(&police->tcf_lock);
return police->tcfp_result;
}
now = ktime_get_ns();
toks = min_t(s64, now - police->tcfp_t_c,
police->tcfp_burst);
if (police->peak_present) {
ptoks = toks + police->tcfp_ptoks;
if (ptoks > police->tcfp_mtu_ptoks)
ptoks = police->tcfp_mtu_ptoks;
ptoks -= (s64) psched_l2t_ns(&police->peak,
qdisc_pkt_len(skb));
}
toks += police->tcfp_toks;
if (toks > police->tcfp_burst)
toks = police->tcfp_burst;
toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
if ((toks|ptoks) >= 0) {
police->tcfp_t_c = now;
police->tcfp_toks = toks;
police->tcfp_ptoks = ptoks;
spin_unlock(&police->tcf_lock);
return police->tcfp_result;
}
}
police->tcf_qstats.overlimits++;
if (police->tcf_action == TC_ACT_SHOT)
police->tcf_qstats.drops++;
spin_unlock(&police->tcf_lock);
return police->tcf_action;
}
static int
tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_police *police = a->priv;
struct tc_police opt = {
.index = police->tcf_index,
.action = police->tcf_action,
.mtu = police->tcfp_mtu,
.burst = PSCHED_NS2TICKS(police->tcfp_burst),
.refcnt = police->tcf_refcnt - ref,
.bindcnt = police->tcf_bindcnt - bind,
};
if (police->rate_present)
psched_ratecfg_getrate(&opt.rate, &police->rate);
if (police->peak_present)
psched_ratecfg_getrate(&opt.peakrate, &police->peak);
if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
goto nla_put_failure;
if (police->tcfp_result &&
nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
goto nla_put_failure;
if (police->tcfp_ewma_rate &&
nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
MODULE_AUTHOR("Alexey Kuznetsov");
MODULE_DESCRIPTION("Policing actions");
MODULE_LICENSE("GPL");
static struct tc_action_ops act_police_ops = {
.kind = "police",
.type = TCA_ID_POLICE,
.owner = THIS_MODULE,
.act = tcf_act_police,
.dump = tcf_act_police_dump,
.init = tcf_act_police_locate,
.walk = tcf_act_police_walker
};
static int __init
police_init_module(void)
{
return tcf_register_action(&act_police_ops, POL_TAB_MASK);
}
static void __exit
police_cleanup_module(void)
{
tcf_unregister_action(&act_police_ops);
}
module_init(police_init_module);
module_exit(police_cleanup_module);