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/*
* net/sched/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>
*/
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#define L2T(p,L) ((p)->R_tab->data[(L)>>(p)->R_tab->rate.cell_log])
#define L2T_P(p,L) ((p)->P_tab->data[(L)>>(p)->P_tab->rate.cell_log])
static u32 idx_gen;
static struct tcf_police *tcf_police_ht[16];
/* Policer hash table lock */
static rwlock_t police_lock = RW_LOCK_UNLOCKED;
/* Each policer is serialized by its individual spinlock */
static __inline__ unsigned tcf_police_hash(u32 index)
{
return index&0xF;
}
static __inline__ struct tcf_police * tcf_police_lookup(u32 index)
{
struct tcf_police *p;
read_lock(&police_lock);
for (p = tcf_police_ht[tcf_police_hash(index)]; p; p = p->next) {
if (p->index == index)
break;
}
read_unlock(&police_lock);
return p;
}
static __inline__ u32 tcf_police_new_index(void)
{
do {
if (++idx_gen == 0)
idx_gen = 1;
} while (tcf_police_lookup(idx_gen));
return idx_gen;
}
void tcf_police_destroy(struct tcf_police *p)
{
unsigned h = tcf_police_hash(p->index);
struct tcf_police **p1p;
for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->next) {
if (*p1p == p) {
write_lock_bh(&police_lock);
*p1p = p->next;
write_unlock_bh(&police_lock);
#ifdef CONFIG_NET_ESTIMATOR
qdisc_kill_estimator(&p->stats);
#endif
if (p->R_tab)
qdisc_put_rtab(p->R_tab);
if (p->P_tab)
qdisc_put_rtab(p->P_tab);
kfree(p);
return;
}
}
BUG_TRAP(0);
}
struct tcf_police * tcf_police_locate(struct rtattr *rta, struct rtattr *est)
{
unsigned h;
struct tcf_police *p;
struct rtattr *tb[TCA_POLICE_MAX];
struct tc_police *parm;
if (rtattr_parse(tb, TCA_POLICE_MAX, RTA_DATA(rta), RTA_PAYLOAD(rta)) < 0)
return NULL;
if (tb[TCA_POLICE_TBF-1] == NULL)
return NULL;
parm = RTA_DATA(tb[TCA_POLICE_TBF-1]);
if (parm->index && (p = tcf_police_lookup(parm->index)) != NULL) {
p->refcnt++;
return p;
}
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL)
return NULL;
memset(p, 0, sizeof(*p));
p->refcnt = 1;
spin_lock_init(&p->lock);
p->stats.lock = &p->lock;
if (parm->rate.rate) {
if ((p->R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE-1])) == NULL)
goto failure;
if (parm->peakrate.rate &&
(p->P_tab = qdisc_get_rtab(&parm->peakrate, tb[TCA_POLICE_PEAKRATE-1])) == NULL)
goto failure;
}
if (tb[TCA_POLICE_RESULT-1])
p->result = *(int*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
#ifdef CONFIG_NET_ESTIMATOR
if (tb[TCA_POLICE_AVRATE-1])
p->ewma_rate = *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
#endif
p->toks = p->burst = parm->burst;
p->mtu = parm->mtu;
if (p->mtu == 0) {
p->mtu = ~0;
if (p->R_tab)
p->mtu = 255<<p->R_tab->rate.cell_log;
}
if (p->P_tab)
p->ptoks = L2T_P(p, p->mtu);
PSCHED_GET_TIME(p->t_c);
p->index = parm->index ? : tcf_police_new_index();
p->action = parm->action;
#ifdef CONFIG_NET_ESTIMATOR
if (est)
qdisc_new_estimator(&p->stats, est);
#endif
h = tcf_police_hash(p->index);
write_lock_bh(&police_lock);
p->next = tcf_police_ht[h];
tcf_police_ht[h] = p;
write_unlock_bh(&police_lock);
return p;
failure:
if (p->R_tab)
qdisc_put_rtab(p->R_tab);
kfree(p);
return NULL;
}
int tcf_police(struct sk_buff *skb, struct tcf_police *p)
{
psched_time_t now;
long toks;
long ptoks = 0;
spin_lock(&p->lock);
p->stats.bytes += skb->len;
p->stats.packets++;
#ifdef CONFIG_NET_ESTIMATOR
if (p->ewma_rate && p->stats.bps >= p->ewma_rate) {
p->stats.overlimits++;
spin_unlock(&p->lock);
return p->action;
}
#endif
if (skb->len <= p->mtu) {
if (p->R_tab == NULL) {
spin_unlock(&p->lock);
return p->result;
}
PSCHED_GET_TIME(now);
toks = PSCHED_TDIFF_SAFE(now, p->t_c, p->burst, 0);
if (p->P_tab) {
ptoks = toks + p->ptoks;
if (ptoks > (long)L2T_P(p, p->mtu))
ptoks = (long)L2T_P(p, p->mtu);
ptoks -= L2T_P(p, skb->len);
}
toks += p->toks;
if (toks > (long)p->burst)
toks = p->burst;
toks -= L2T(p, skb->len);
if ((toks|ptoks) >= 0) {
p->t_c = now;
p->toks = toks;
p->ptoks = ptoks;
spin_unlock(&p->lock);
return p->result;
}
}
p->stats.overlimits++;
spin_unlock(&p->lock);
return p->action;
}
int tcf_police_dump(struct sk_buff *skb, struct tcf_police *p)
{
unsigned char *b = skb->tail;
struct tc_police opt;
opt.index = p->index;
opt.action = p->action;
opt.mtu = p->mtu;
opt.burst = p->burst;
if (p->R_tab)
opt.rate = p->R_tab->rate;
else
memset(&opt.rate, 0, sizeof(opt.rate));
if (p->P_tab)
opt.peakrate = p->P_tab->rate;
else
memset(&opt.peakrate, 0, sizeof(opt.peakrate));
RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
if (p->result)
RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int), &p->result);
#ifdef CONFIG_NET_ESTIMATOR
if (p->ewma_rate)
RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &p->ewma_rate);
#endif
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
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