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netfilter: conntrack: replace notify chain by function pointer

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This patch removes the notify chain infrastructure and replace it
by a simple function pointer. This issue has been mentioned in the
mailing list several times: the use of the notify chain adds
too much overhead for something that is only used by ctnetlink.

This patch also changes nfnetlink_send(). It seems that gfp_any()
returns GFP_KERNEL for user-context request, like those via
ctnetlink, inside the RCU read-side section which is not valid.
Using GFP_KERNEL is also evil since netlink may schedule(),
this leads to "scheduling while atomic" bug reports.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso
2009-06-03 10:32:06 +02:00
committed by pablo
parent 17e6e4eac0
commit e34d5c1a4f
5 changed files with 139 additions and 61 deletions
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68
include/net/netfilter/nf_conntrack_ecache.h
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@@ -6,7 +6,6 @@
#define _NF_CONNTRACK_ECACHE_H
#include <net/netfilter/nf_conntrack.h>
#include <linux/notifier.h>
#include <linux/interrupt.h>
#include <net/net_namespace.h>
#include <net/netfilter/nf_conntrack_expect.h>
@@ -69,9 +68,13 @@ struct nf_ct_event {
int report;
};
extern struct atomic_notifier_head nf_conntrack_chain;
extern int nf_conntrack_register_notifier(struct notifier_block *nb);
extern int nf_conntrack_unregister_notifier(struct notifier_block *nb);
struct nf_ct_event_notifier {
int (*fcn)(unsigned int events, struct nf_ct_event *item);
};
extern struct nf_ct_event_notifier *nf_conntrack_event_cb;
extern int nf_conntrack_register_notifier(struct nf_ct_event_notifier *nb);
extern void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *nb);
extern void nf_ct_deliver_cached_events(const struct nf_conn *ct);
extern void __nf_ct_event_cache_init(struct nf_conn *ct);
@@ -97,13 +100,23 @@ nf_conntrack_event_report(enum ip_conntrack_events event,
u32 pid,
int report)
{
struct nf_ct_event item = {
.ct = ct,
.pid = pid,
.report = report
};
if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct))
atomic_notifier_call_chain(&nf_conntrack_chain, event, &item);
struct nf_ct_event_notifier *notify;
rcu_read_lock();
notify = rcu_dereference(nf_conntrack_event_cb);
if (notify == NULL)
goto out_unlock;
if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct)) {
struct nf_ct_event item = {
.ct = ct,
.pid = pid,
.report = report
};
notify->fcn(event, &item);
}
out_unlock:
rcu_read_unlock();
}
static inline void
@@ -118,9 +131,13 @@ struct nf_exp_event {
int report;
};
extern struct atomic_notifier_head nf_ct_expect_chain;
extern int nf_ct_expect_register_notifier(struct notifier_block *nb);
extern int nf_ct_expect_unregister_notifier(struct notifier_block *nb);
struct nf_exp_event_notifier {
int (*fcn)(unsigned int events, struct nf_exp_event *item);
};
extern struct nf_exp_event_notifier *nf_expect_event_cb;
extern int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *nb);
extern void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *nb);
static inline void
nf_ct_expect_event_report(enum ip_conntrack_expect_events event,
@@ -128,12 +145,23 @@ nf_ct_expect_event_report(enum ip_conntrack_expect_events event,
u32 pid,
int report)
{
struct nf_exp_event item = {
.exp = exp,
.pid = pid,
.report = report
};
atomic_notifier_call_chain(&nf_ct_expect_chain, event, &item);
struct nf_exp_event_notifier *notify;
rcu_read_lock();
notify = rcu_dereference(nf_expect_event_cb);
if (notify == NULL)
goto out_unlock;
{
struct nf_exp_event item = {
.exp = exp,
.pid = pid,
.report = report
};
notify->fcn(event, &item);
}
out_unlock:
rcu_read_unlock();
}
static inline void