/*
* Connection state tracking for netfilter. This is separated from,
* but required by, the (future) NAT layer; it can also be used by an iptables
* extension.
*
* 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
* - generalize L3 protocol dependent part.
*
* Derived from include/linux/netfiter_ipv4/ip_conntrack.h
*/
#ifndef _NF_CONNTRACK_H
#define _NF_CONNTRACK_H
#include <linux/netfilter/nf_conntrack_common.h>
#ifdef __KERNEL__
#include <linux/config.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <asm/atomic.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/nf_conntrack_sctp.h>
#include <net/netfilter/ipv4/nf_conntrack_icmp.h>
#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
#include <net/netfilter/nf_conntrack_tuple.h>
/* per conntrack: protocol private data */
union nf_conntrack_proto {
/* insert conntrack proto private data here */
struct ip_ct_sctp sctp;
struct ip_ct_tcp tcp;
struct ip_ct_icmp icmp;
struct nf_ct_icmpv6 icmpv6;
};
union nf_conntrack_expect_proto {
/* insert expect proto private data here */
};
/* Add protocol helper include file here */
#include <linux/netfilter/nf_conntrack_ftp.h>
/* per conntrack: application helper private data */
union nf_conntrack_help {
/* insert conntrack helper private data (master) here */
struct ip_ct_ftp_master ct_ftp_info;
};
#include <linux/types.h>
#include <linux/skbuff.h>
#ifdef CONFIG_NETFILTER_DEBUG
#define NF_CT_ASSERT(x) \
do { \
if (!(x)) \
/* Wooah! I'm tripping my conntrack in a frenzy of \
netplay... */ \
printk("NF_CT_ASSERT: %s:%i(%s)\n", \
__FILE__, __LINE__, __FUNCTION__); \
} while(0)
#else
#define NF_CT_ASSERT(x)
#endif
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
{
/* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
plus 1 for any connection(s) we are `master' for */
struct nf_conntrack ct_general;
/* XXX should I move this to the tail ? - Y.K */
/* These are my tuples; original and reply */
struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
/* 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;
#ifdef CONFIG_NF_CT_ACCT
/* Accounting Information (same cache line as other written members) */
struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
#endif
/* Unique ID that identifies this conntrack*/
unsigned int id;
/* features - nat, helper, ... used by allocating system */
u_int32_t features;
#if defined(CONFIG_NF_CONNTRACK_MARK)
u_int32_t mark;
#endif
/* Storage reserved for other modules: */
union nf_conntrack_proto proto;
/* features dynamically at the end: helper, nat (both optional) */
char data[0];
};
struct nf_conntrack_expect
{
/* Internal linked list (global expectation list) */
struct list_head list;
/* We expect this tuple, with the following mask */
struct nf_conntrack_tuple tuple, mask;
/* Function to call after setup and insertion */
void (*expectfn)(struct nf_conn *new,
struct nf_conntrack_expect *this);
/* The conntrack of the master connection */
struct nf_conn *master;
/* Timer function; deletes the expectation. */
struct timer_list timeout;
/* Usage count. */
atomic_t use;
/* Unique ID */
unsigned int id;
/* Flags */
unsigned int flags;
#ifdef CONFIG_NF_NAT_NEEDED
/* This is the original per-proto part, used to map the
* expected connection the way the recipient expects. */
union nf_conntrack_manip_proto saved_proto;
/* Direction relative to the master connection. */
enum ip_conntrack_dir dir;
#endif
};
#define NF_CT_EXPECT_PERMANENT 0x1
static inline struct nf_conn *
nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
{
return container_of(hash, struct nf_conn,
tuplehash[hash->tuple.dst.dir]);
}
/* get master conntrack via master expectation */
#define master_ct(conntr) (conntr->master)
/* Alter reply tuple (maybe alter helper). */
extern void
nf_conntrack_alter_reply(struct nf_conn *conntrack,
const struct nf_conntrack_tuple *newreply);
/* Is this tuple taken? (ignoring any belonging to the given
conntrack). */
extern int
nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack);
/* Return conntrack_info and tuple hash for given skb. */
static inline struct nf_conn *
nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
{
*ctinfo = skb->nfctinfo;
return (struct nf_conn *)skb->nfct;
}
/* decrement reference count on a conntrack */
static inline void nf_ct_put(struct nf_conn *ct)
{
NF_CT_ASSERT(ct);
nf_conntrack_put(&ct->ct_general);
}
/* Protocol module loading */
extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
extern void nf_ct_l3proto_module_put(unsigned short l3proto);
extern struct nf_conntrack_tuple_hash *
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack);
extern void nf_conntrack_hash_insert(struct nf_conn *ct);
extern struct nf_conntrack_expect *
__nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple);
extern struct nf_conntrack_expect *
nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple);
extern void nf_ct_unlink_expect(struct nf_conntrack_expect *exp);
extern void nf_ct_remove_expectations(struct nf_conn *ct);
extern void nf_conntrack_flush(void);
extern struct nf_conntrack_helper *
nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple);
extern void nf_ct_helper_put(struct nf_conntrack_helper *helper);
extern struct nf_conntrack_helper *
__nf_conntrack_helper_find_byname(const char *name);
extern int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
const struct nf_conntrack_tuple *orig);
extern void __nf_ct_refresh_acct(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
const struct sk_buff *skb,
unsigned long extra_jiffies,
int do_acct);
/* Refresh conntrack for this many jiffies and do accounting */
static inline void nf_ct_refresh_acct(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
const struct sk_buff *skb,
unsigned long extra_jiffies)
{
__nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
}
/* Refresh conntrack for this many jiffies */
static inline void nf_ct_refresh(struct nf_conn *ct,
const struct sk_buff *skb,
unsigned long extra_jiffies)
{
__nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
}
/* These are for NAT. Icky. */
/* Update TCP window tracking data when NAT mangles the packet */
extern void nf_conntrack_tcp_update(struct sk_buff *skb,
unsigned int dataoff,
struct nf_conn *conntrack,
int dir);
/* Call me when a conntrack is destroyed. */
extern void (*nf_conntrack_destroyed)(struct nf_conn *conntrack);
/* Fake conntrack entry for untracked connections */
extern struct nf_conn nf_conntrack_untracked;
extern int nf_ct_no_defrag;
/* Iterate over all conntracks: if iter returns true, it's deleted. */
extern void
nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data);
extern void nf_conntrack_free(struct nf_conn *ct);
extern struct nf_conn *
nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl);
/* It's confirmed if it is, or has been in the hash table. */
static inline int nf_ct_is_confirmed(struct nf_conn *ct)
{
return test_bit(IPS_CONFIRMED_BIT, &ct->status);
}
static inline int nf_ct_is_dying(struct nf_conn *ct)
{
return test_bit(IPS_DYING_BIT, &ct->status);
}
extern unsigned int nf_conntrack_htable_size;
extern int nf_conntrack_checksum;
#define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++)
#ifdef CONFIG_NF_CONNTRACK_EVENTS
#include <linux/notifier.h>
#include <linux/interrupt.h>
struct nf_conntrack_ecache {
struct nf_conn *ct;
unsigned int events;
};
DECLARE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache);
#define CONNTRACK_ECACHE(x) (__get_cpu_var(nf_conntrack_ecache).x)
extern struct atomic_notifier_head nf_conntrack_chain;
extern struct atomic_notifier_head nf_conntrack_expect_chain;
static inline int nf_conntrack_register_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&nf_conntrack_chain, nb);
}
static inline int nf_conntrack_unregister_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&nf_conntrack_chain, nb);
}
static inline int
nf_conntrack_expect_register_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&nf_conntrack_expect_chain, nb);
}
static inline int
nf_conntrack_expect_unregister_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&nf_conntrack_expect_chain,
nb);
}
extern void nf_ct_deliver_cached_events(const struct nf_conn *ct);
extern void __nf_ct_event_cache_init(struct nf_conn *ct);
static inline void
nf_conntrack_event_cache(enum ip_conntrack_events event,
const struct sk_buff *skb)
{
struct nf_conn *ct = (struct nf_conn *)skb->nfct;
struct nf_conntrack_ecache *ecache;
local_bh_disable();
ecache = &__get_cpu_var(nf_conntrack_ecache);
if (ct != ecache->ct)
__nf_ct_event_cache_init(ct);
ecache->events |= event;
local_bh_enable();
}
static inline void nf_conntrack_event(enum ip_conntrack_events event,
struct nf_conn *ct)
{
if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct))
atomic_notifier_call_chain(&nf_conntrack_chain, event, ct);
}
static inline void
nf_conntrack_expect_event(enum ip_conntrack_expect_events event,
struct nf_conntrack_expect *exp)
{
atomic_notifier_call_chain(&nf_conntrack_expect_chain, event, exp);
}
#else /* CONFIG_NF_CONNTRACK_EVENTS */
static inline void nf_conntrack_event_cache(enum ip_conntrack_events event,
const struct sk_buff *skb) {}
static inline void nf_conntrack_event(enum ip_conntrack_events event,
struct nf_conn *ct) {}
static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct) {}
static inline void
nf_conntrack_expect_event(enum ip_conntrack_expect_events event,
struct nf_conntrack_expect *exp) {}
#endif /* CONFIG_NF_CONNTRACK_EVENTS */
/* no helper, no nat */
#define NF_CT_F_BASIC 0
/* for helper */
#define NF_CT_F_HELP 1
/* for nat. */
#define NF_CT_F_NAT 2
#define NF_CT_F_NUM 4
extern int
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 */
