net_sched: act: refuse to remove bound action outside

When an action is bonnd to a filter, there is no point to
remove it outside. Currently we just silently decrease the refcnt,
we should reject this explicitly with EPERM.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
WANG Cong 2014-02-11 17:07:34 -08:00 committed by David S. Miller
parent 4f1e9d8949
commit 55334a5db5
2 changed files with 21 additions and 7 deletions

View file

@ -109,7 +109,7 @@ void tcf_hash_insert(struct tc_action *a);
int tcf_register_action(struct tc_action_ops *a, unsigned int mask); int tcf_register_action(struct tc_action_ops *a, unsigned int mask);
int tcf_unregister_action(struct tc_action_ops *a); int tcf_unregister_action(struct tc_action_ops *a);
void tcf_action_destroy(struct list_head *actions, int bind); int tcf_action_destroy(struct list_head *actions, int bind);
int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions, int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
struct tcf_result *res); struct tcf_result *res);
int tcf_action_init(struct net *net, struct nlattr *nla, int tcf_action_init(struct net *net, struct nlattr *nla,

View file

@ -53,6 +53,8 @@ int tcf_hash_release(struct tc_action *a, int bind)
if (p) { if (p) {
if (bind) if (bind)
p->tcfc_bindcnt--; p->tcfc_bindcnt--;
else if (p->tcfc_bindcnt > 0)
return -EPERM;
p->tcfc_refcnt--; p->tcfc_refcnt--;
if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) { if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
@ -123,6 +125,7 @@ static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
struct tcf_common *p; struct tcf_common *p;
struct nlattr *nest; struct nlattr *nest;
int i = 0, n_i = 0; int i = 0, n_i = 0;
int ret = -EINVAL;
nest = nla_nest_start(skb, a->order); nest = nla_nest_start(skb, a->order);
if (nest == NULL) if (nest == NULL)
@ -133,10 +136,12 @@ static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
head = &hinfo->htab[tcf_hash(i, hinfo->hmask)]; head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
hlist_for_each_entry_safe(p, n, head, tcfc_head) { hlist_for_each_entry_safe(p, n, head, tcfc_head) {
a->priv = p; a->priv = p;
if (ACT_P_DELETED == tcf_hash_release(a, 0)) { ret = tcf_hash_release(a, 0);
if (ret == ACT_P_DELETED) {
module_put(a->ops->owner); module_put(a->ops->owner);
n_i++; n_i++;
} } else if (ret < 0)
goto nla_put_failure;
} }
} }
if (nla_put_u32(skb, TCA_FCNT, n_i)) if (nla_put_u32(skb, TCA_FCNT, n_i))
@ -146,7 +151,7 @@ static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
return n_i; return n_i;
nla_put_failure: nla_put_failure:
nla_nest_cancel(skb, nest); nla_nest_cancel(skb, nest);
return -EINVAL; return ret;
} }
static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb, static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
@ -401,16 +406,21 @@ exec_done:
} }
EXPORT_SYMBOL(tcf_action_exec); EXPORT_SYMBOL(tcf_action_exec);
void tcf_action_destroy(struct list_head *actions, int bind) int tcf_action_destroy(struct list_head *actions, int bind)
{ {
struct tc_action *a, *tmp; struct tc_action *a, *tmp;
int ret = 0;
list_for_each_entry_safe(a, tmp, actions, list) { list_for_each_entry_safe(a, tmp, actions, list) {
if (tcf_hash_release(a, bind) == ACT_P_DELETED) ret = tcf_hash_release(a, bind);
if (ret == ACT_P_DELETED)
module_put(a->ops->owner); module_put(a->ops->owner);
else if (ret < 0)
return ret;
list_del(&a->list); list_del(&a->list);
kfree(a); kfree(a);
} }
return ret;
} }
int int
@ -838,7 +848,11 @@ tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
} }
/* now do the delete */ /* now do the delete */
tcf_action_destroy(actions, 0); ret = tcf_action_destroy(actions, 0);
if (ret < 0) {
kfree_skb(skb);
return ret;
}
ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC, ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO); n->nlmsg_flags & NLM_F_ECHO);