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/*
* 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 tc_action 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) ((struct tcf_police *)pc)
#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 police_net_id;
static struct tc_action_ops act_police_ops;
static int tcf_act_police_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, police_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
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_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind)
{
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 tc_action_net *tn = net_generic(net, police_net_id);
bool exists = false;
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]);
exists = tcf_hash_check(tn, parm->index, a, bind);
if (exists && bind)
return 0;
if (!exists) {
ret = tcf_hash_create(tn, parm->index, NULL, a,
&act_police_ops, bind, false);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
tcf_hash_release(*a, bind);
if (!ovr)
return -EEXIST;
}
police = to_police(*a);
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,
NULL, 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();
tcf_hash_insert(tn, *a);
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)
tcf_hash_cleanup(*a, est);
return err;
}
static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_police *police = to_police(a);
s64 now;
s64 toks;
s64 ptoks = 0;
spin_lock(&police->tcf_lock);
bstats_update(&police->tcf_bstats, skb);
tcf_lastuse_update(&police->tcf_tm);
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
|