linux/net/sched/act_skbedit.c
Jamal Hadi Salim 1a29321ed0 net_sched: act: Dont increment refcnt on replace
This is a bug fix. The existing code tries to kill many
 birds with one stone: Handling binding of actions to
 filters, new actions and replacing of action
 attributes. A simple test case to illustrate:

XXXX
 moja@fe1:~$ sudo tc actions add action drop index 12
 moja@fe1:~$ actions get action gact index 12
 action order 1: gact action drop
  random type none pass val 0
  index 12 ref 1 bind 0
 moja@fe1:~$ sudo tc actions replace action ok index 12
 moja@fe1:~$ actions get action gact index 12
 action order 1: gact action drop
  random type none pass val 0
  index 12 ref 2 bind 0
XXXX

The above shows the refcounf being wrongly incremented on replace.
There are more complex scenarios with binding of actions to filters
that i am leaving out that didnt work as well...

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-27 12:50:00 -05:00

225 lines
5.9 KiB
C

/*
* Copyright (c) 2008, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* Author: Alexander Duyck <alexander.h.duyck@intel.com>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_skbedit.h>
#include <net/tc_act/tc_skbedit.h>
#define SKBEDIT_TAB_MASK 15
static struct tcf_common *tcf_skbedit_ht[SKBEDIT_TAB_MASK + 1];
static u32 skbedit_idx_gen;
static DEFINE_RWLOCK(skbedit_lock);
static struct tcf_hashinfo skbedit_hash_info = {
.htab = tcf_skbedit_ht,
.hmask = SKBEDIT_TAB_MASK,
.lock = &skbedit_lock,
};
static int tcf_skbedit(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_skbedit *d = a->priv;
spin_lock(&d->tcf_lock);
d->tcf_tm.lastuse = jiffies;
bstats_update(&d->tcf_bstats, skb);
if (d->flags & SKBEDIT_F_PRIORITY)
skb->priority = d->priority;
if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
skb->dev->real_num_tx_queues > d->queue_mapping)
skb_set_queue_mapping(skb, d->queue_mapping);
if (d->flags & SKBEDIT_F_MARK)
skb->mark = d->mark;
spin_unlock(&d->tcf_lock);
return d->tcf_action;
}
static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
[TCA_SKBEDIT_PARMS] = { .len = sizeof(struct tc_skbedit) },
[TCA_SKBEDIT_PRIORITY] = { .len = sizeof(u32) },
[TCA_SKBEDIT_QUEUE_MAPPING] = { .len = sizeof(u16) },
[TCA_SKBEDIT_MARK] = { .len = sizeof(u32) },
};
static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action *a,
int ovr, int bind)
{
struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
struct tc_skbedit *parm;
struct tcf_skbedit *d;
struct tcf_common *pc;
u32 flags = 0, *priority = NULL, *mark = NULL;
u16 *queue_mapping = NULL;
int ret = 0, err;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy);
if (err < 0)
return err;
if (tb[TCA_SKBEDIT_PARMS] == NULL)
return -EINVAL;
if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
flags |= SKBEDIT_F_PRIORITY;
priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
}
if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
flags |= SKBEDIT_F_QUEUE_MAPPING;
queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
}
if (tb[TCA_SKBEDIT_MARK] != NULL) {
flags |= SKBEDIT_F_MARK;
mark = nla_data(tb[TCA_SKBEDIT_MARK]);
}
if (!flags)
return -EINVAL;
parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
pc = tcf_hash_check(parm->index, a, bind, &skbedit_hash_info);
if (!pc) {
pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
&skbedit_idx_gen, &skbedit_hash_info);
if (IS_ERR(pc))
return PTR_ERR(pc);
d = to_skbedit(pc);
ret = ACT_P_CREATED;
} else {
d = to_skbedit(pc);
if (bind)
return 0;
tcf_hash_release(pc, bind, &skbedit_hash_info);
if (!ovr)
return -EEXIST;
}
spin_lock_bh(&d->tcf_lock);
d->flags = flags;
if (flags & SKBEDIT_F_PRIORITY)
d->priority = *priority;
if (flags & SKBEDIT_F_QUEUE_MAPPING)
d->queue_mapping = *queue_mapping;
if (flags & SKBEDIT_F_MARK)
d->mark = *mark;
d->tcf_action = parm->action;
spin_unlock_bh(&d->tcf_lock);
if (ret == ACT_P_CREATED)
tcf_hash_insert(pc, &skbedit_hash_info);
return ret;
}
static int tcf_skbedit_cleanup(struct tc_action *a, int bind)
{
struct tcf_skbedit *d = a->priv;
if (d)
return tcf_hash_release(&d->common, bind, &skbedit_hash_info);
return 0;
}
static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_skbedit *d = a->priv;
struct tc_skbedit opt = {
.index = d->tcf_index,
.refcnt = d->tcf_refcnt - ref,
.bindcnt = d->tcf_bindcnt - bind,
.action = d->tcf_action,
};
struct tcf_t t;
if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
if ((d->flags & SKBEDIT_F_PRIORITY) &&
nla_put(skb, TCA_SKBEDIT_PRIORITY, sizeof(d->priority),
&d->priority))
goto nla_put_failure;
if ((d->flags & SKBEDIT_F_QUEUE_MAPPING) &&
nla_put(skb, TCA_SKBEDIT_QUEUE_MAPPING,
sizeof(d->queue_mapping), &d->queue_mapping))
goto nla_put_failure;
if ((d->flags & SKBEDIT_F_MARK) &&
nla_put(skb, TCA_SKBEDIT_MARK, sizeof(d->mark),
&d->mark))
goto nla_put_failure;
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);
if (nla_put(skb, TCA_SKBEDIT_TM, sizeof(t), &t))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static struct tc_action_ops act_skbedit_ops = {
.kind = "skbedit",
.hinfo = &skbedit_hash_info,
.type = TCA_ACT_SKBEDIT,
.capab = TCA_CAP_NONE,
.owner = THIS_MODULE,
.act = tcf_skbedit,
.dump = tcf_skbedit_dump,
.cleanup = tcf_skbedit_cleanup,
.init = tcf_skbedit_init,
};
MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
MODULE_DESCRIPTION("SKB Editing");
MODULE_LICENSE("GPL");
static int __init skbedit_init_module(void)
{
return tcf_register_action(&act_skbedit_ops);
}
static void __exit skbedit_cleanup_module(void)
{
tcf_unregister_action(&act_skbedit_ops);
}
module_init(skbedit_init_module);
module_exit(skbedit_cleanup_module);