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[NETFILTER] nf_conntrack: clean up to reduce size of 'struct nf_conn'

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This patch moves all helper related data fields of 'struct nf_conn'
into a separate structure 'struct nf_conn_help'.  This new structure
is only present in conntrack entries for which we actually have a
helper loaded.

Also, this patch cleans up the nf_conntrack 'features' mechanism to
resemble what the original idea was: Just glue the feature-specific
data structures at the end of 'struct nf_conn', and explicitly
re-calculate the pointer to it when needed rather than keeping
pointers around.

Saves 20 bytes per conntrack on my x86_64 box. A non-helped conntrack
is 276 bytes. We still need to save another 20 bytes in order to fit
into to target of 256bytes.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harald Welte
2006-03-20 17:56:32 -08:00
committed by David S. Miller
parent 0d36f37bb1
commit dc808fe28d
8 changed files with 147 additions and 137 deletions
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56
include/net/netfilter/nf_conntrack.h
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@@ -67,6 +67,18 @@ do { \
struct nf_conntrack_helper;
/* nf_conn feature for connections that have a helper */
struct nf_conn_help {
/* Helper. if any */
struct nf_conntrack_helper *helper;
union nf_conntrack_help help;
/* Current number of expected connections */
unsigned int expecting;
};
#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
struct nf_conn
{
@@ -81,6 +93,9 @@ struct nf_conn
/* Have we seen traffic both ways yet? (bitset) */
unsigned long status;
/* If we were expected by an expectation, this will be it */
struct nf_conn *master;
/* Timer function; drops refcnt when it goes off. */
struct timer_list timeout;
@@ -88,38 +103,22 @@ struct nf_conn
/* Accounting Information (same cache line as other written members) */
struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
#endif
/* If we were expected by an expectation, this will be it */
struct nf_conn *master;
/* Current number of expected connections */
unsigned int expecting;
/* Unique ID that identifies this conntrack*/
unsigned int id;
/* Helper. if any */
struct nf_conntrack_helper *helper;
/* features - nat, helper, ... used by allocating system */
u_int32_t features;
/* Storage reserved for other modules: */
union nf_conntrack_proto proto;
#if defined(CONFIG_NF_CONNTRACK_MARK)
u_int32_t mark;
#endif
/* These members are dynamically allocated. */
/* Storage reserved for other modules: */
union nf_conntrack_proto proto;
union nf_conntrack_help *help;
/* Layer 3 dependent members. (ex: NAT) */
union {
struct nf_conntrack_ipv4 *ipv4;
} l3proto;
void *data[0];
/* features dynamically at the end: helper, nat (both optional) */
char data[0];
};
struct nf_conntrack_expect
@@ -373,10 +372,23 @@ nf_conntrack_expect_event(enum ip_conntrack_expect_events event,
#define NF_CT_F_NUM 4
extern int
nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size,
int (*init_conntrack)(struct nf_conn *, u_int32_t));
nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size);
extern void
nf_conntrack_unregister_cache(u_int32_t features);
/* valid combinations:
* basic: nf_conn, nf_conn .. nf_conn_help
* nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat, nf_conn help
*/
static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{
unsigned int offset = sizeof(struct nf_conn);
if (!(ct->features & NF_CT_F_HELP))
return NULL;
return (struct nf_conn_help *) ((void *)ct + offset);
}
#endif /* __KERNEL__ */
#endif /* _NF_CONNTRACK_H */