act_simple.c
/*
* net/sched/simp.c Simple example of an action
*
* 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: Jamal Hadi Salim (2005)
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/pkt_sched.h>
#define TCA_ACT_SIMP 22
#include <linux/tc_act/tc_defact.h>
#include <net/tc_act/tc_defact.h>
#define SIMP_TAB_MASK 7
static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1];
static u32 simp_idx_gen;
static DEFINE_RWLOCK(simp_lock);
static struct tcf_hashinfo simp_hash_info = {
.htab = tcf_simp_ht,
.hmask = SIMP_TAB_MASK,
.lock = &simp_lock,
};
static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
{
struct tcf_defact *d = a->priv;
spin_lock(&d->tcf_lock);
d->tcf_tm.lastuse = jiffies;
d->tcf_bstats.bytes += skb->len;
d->tcf_bstats.packets++;
/* print policy string followed by _ then packet count
* Example if this was the 3rd packet and the string was "hello"
* then it would look like "hello_3" (without quotes)
**/
printk("simple: %s_%d\n",
(char *)d->tcfd_defdata, d->tcf_bstats.packets);
spin_unlock(&d->tcf_lock);
return d->tcf_action;
}
static int tcf_simp_release(struct tcf_defact *d, int bind)
{
int ret = 0;
if (d) {
if (bind)
d->tcf_bindcnt--;
d->tcf_refcnt--;
if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) {
kfree(d->tcfd_defdata);
tcf_hash_destroy(&d->common, &simp_hash_info);
ret = 1;
}
}
return ret;
}
static int alloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata)
{
d->tcfd_defdata = kmemdup(defdata, datalen, GFP_KERNEL);
if (unlikely(!d->tcfd_defdata))
return -ENOMEM;
d->tcfd_datalen = datalen;
return 0;
}
static int realloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata)
{
kfree(d->tcfd_defdata);
return alloc_defdata(d, datalen, defdata);
}
static int tcf_simp_init(struct rtattr *rta, struct rtattr *est,
struct tc_action *a, int ovr, int bind)
{
struct rtattr *tb[TCA_DEF_MAX];
struct tc_defact *parm;
struct tcf_defact *d;
struct tcf_common *pc;
void *defdata;
u32 datalen = 0;
int ret = 0;
if (rta == NULL || rtattr_parse_nested(tb, TCA_DEF_MAX, rta) < 0)
return -EINVAL;
if (tb[TCA_DEF_PARMS - 1] == NULL ||
RTA_PAYLOAD(tb[TCA_DEF_PARMS - 1]) < sizeof(*parm))
return -EINVAL;
parm = RTA_DATA(tb[TCA_DEF_PARMS - 1]);
defdata = RTA_DATA(tb[TCA_DEF_DATA - 1]);
if (defdata == NULL)
return -EINVAL;
datalen = RTA_PAYLOAD(tb[TCA_DEF_DATA - 1]);
if (datalen <= 0)
return -EINVAL;
pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info);
if (!pc) {
pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
&simp_idx_gen, &simp_hash_info);
if (unlikely(!pc))
return -ENOMEM;
d = to_defact(pc);
ret = alloc_defdata(d, datalen, defdata);
if (ret < 0) {
kfree(pc);
return ret;
}
ret = ACT_P_CREATED;
} else {
d = to_defact(pc);
if (!ovr) {
tcf_simp_release(d, bind);
return -EEXIST;
}
realloc_defdata(d, datalen, defdata);
}
spin_lock_bh(&d->tcf_lock);
d->tcf_action = parm->action;
spin_unlock_bh(&d->tcf_lock);
if (ret == ACT_P_CREATED)
tcf_hash_insert(pc, &simp_hash_info);
return ret;
}
static inline int tcf_simp_cleanup(struct tc_action *a, int bind)
{
struct tcf_defact *d = a->priv;
if (d)
return tcf_simp_release(d, bind);
return 0;
}
static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb->tail;
struct tcf_defact *d = a->priv;
struct tc_defact opt;
struct tcf_t t;
opt.index = d->tcf_index;
opt.refcnt = d->tcf_refcnt - ref;
opt.bindcnt = d->tcf_bindcnt - bind;
opt.action = d->tcf_action;
RTA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt);
RTA_PUT(skb, TCA_DEF_DATA, d->tcfd_datalen, d->tcfd_defdata);
t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
RTA_PUT(skb, TCA_DEF_TM, sizeof(t), &t);
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static struct tc_action_ops act_simp_ops = {
.kind = "simple",
.hinfo = &simp_hash_info,
.type = TCA_ACT_SIMP,
.capab = TCA_CAP_NONE,
.owner = THIS_MODULE,
.act = tcf_simp,
.dump = tcf_simp_dump,
.cleanup = tcf_simp_cleanup,
.init = tcf_simp_init,
.walk = tcf_generic_walker,
};
MODULE_AUTHOR("Jamal Hadi Salim(2005)");
MODULE_DESCRIPTION("Simple example action");
MODULE_LICENSE("GPL");
static int __init simp_init_module(void)
{
int ret = tcf_register_action(&act_simp_ops);
if (!ret)
printk("Simple TC action Loaded\n");
return ret;
}
static void __exit simp_cleanup_module(void)
{
tcf_unregister_action(&act_simp_ops);
}
module_init(simp_init_module);
module_exit(simp_cleanup_module);