kernel-fxtec-pro1x/include/net/netns/conntrack.h
Eric Dumazet 5b3501faa8 netfilter: nf_conntrack: per netns nf_conntrack_cachep
nf_conntrack_cachep is currently shared by all netns instances, but
because of SLAB_DESTROY_BY_RCU special semantics, this is wrong.

If we use a shared slab cache, one object can instantly flight between
one hash table (netns ONE) to another one (netns TWO), and concurrent
reader (doing a lookup in netns ONE, 'finding' an object of netns TWO)
can be fooled without notice, because no RCU grace period has to be
observed between object freeing and its reuse.

We dont have this problem with UDP/TCP slab caches because TCP/UDP
hashtables are global to the machine (and each object has a pointer to
its netns).

If we use per netns conntrack hash tables, we also *must* use per netns
conntrack slab caches, to guarantee an object can not escape from one
namespace to another one.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
[Patrick: added unique slab name allocation]
Cc: stable@kernel.org
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-08 11:16:56 -08:00

34 lines
870 B
C

#ifndef __NETNS_CONNTRACK_H
#define __NETNS_CONNTRACK_H
#include <linux/list.h>
#include <linux/list_nulls.h>
#include <asm/atomic.h>
struct ctl_table_header;
struct nf_conntrack_ecache;
struct netns_ct {
atomic_t count;
unsigned int expect_count;
struct kmem_cache *nf_conntrack_cachep;
struct hlist_nulls_head *hash;
struct hlist_head *expect_hash;
struct hlist_nulls_head unconfirmed;
struct hlist_nulls_head dying;
struct ip_conntrack_stat *stat;
int sysctl_events;
unsigned int sysctl_events_retry_timeout;
int sysctl_acct;
int sysctl_checksum;
unsigned int sysctl_log_invalid; /* Log invalid packets */
#ifdef CONFIG_SYSCTL
struct ctl_table_header *sysctl_header;
struct ctl_table_header *acct_sysctl_header;
struct ctl_table_header *event_sysctl_header;
#endif
int hash_vmalloc;
int expect_vmalloc;
char *slabname;
};
#endif