android_kernel_samsung_msm8976/include/linux/netfilter_ipv4/ip_conntrack.h
Yasuyuki Kozakai 9fb9cbb108 [NETFILTER]: Add nf_conntrack subsystem.
The existing connection tracking subsystem in netfilter can only
handle ipv4.  There were basically two choices present to add
connection tracking support for ipv6.  We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.

In fact nf_conntrack is capable of working with any layer 3
protocol.

The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here.  For example, these issues include:

1) ICMPv6 handling, which is used for neighbour discovery in
   ipv6 thus some messages such as these should not participate
   in connection tracking since effectively they are like ARP
   messages

2) fragmentation must be handled differently in ipv6, because
   the simplistic "defrag, connection track and NAT, refrag"
   (which the existing ipv4 connection tracking does) approach simply
   isn't feasible in ipv6

3) ipv6 extension header parsing must occur at the correct spots
   before and after connection tracking decisions, and there were
   no provisions for this in the existing connection tracking
   design

4) ipv6 has no need for stateful NAT

The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete.  Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-09 16:38:16 -08:00

390 lines
11 KiB
C

#ifndef _IP_CONNTRACK_H
#define _IP_CONNTRACK_H
#include <linux/netfilter/nf_conntrack_common.h>
#ifdef __KERNEL__
#include <linux/config.h>
#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <asm/atomic.h>
#include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
#include <linux/netfilter_ipv4/ip_conntrack_icmp.h>
#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
#include <linux/netfilter_ipv4/ip_conntrack_sctp.h>
/* per conntrack: protocol private data */
union ip_conntrack_proto {
/* insert conntrack proto private data here */
struct ip_ct_gre gre;
struct ip_ct_sctp sctp;
struct ip_ct_tcp tcp;
struct ip_ct_icmp icmp;
};
union ip_conntrack_expect_proto {
/* insert expect proto private data here */
};
/* Add protocol helper include file here */
#include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
#include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
#include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
#include <linux/netfilter_ipv4/ip_conntrack_irc.h>
/* per conntrack: application helper private data */
union ip_conntrack_help {
/* insert conntrack helper private data (master) here */
struct ip_ct_pptp_master ct_pptp_info;
struct ip_ct_ftp_master ct_ftp_info;
struct ip_ct_irc_master ct_irc_info;
};
#ifdef CONFIG_IP_NF_NAT_NEEDED
#include <linux/netfilter_ipv4/ip_nat.h>
#include <linux/netfilter_ipv4/ip_nat_pptp.h>
/* per conntrack: nat application helper private data */
union ip_conntrack_nat_help {
/* insert nat helper private data here */
struct ip_nat_pptp nat_pptp_info;
};
#endif
#include <linux/types.h>
#include <linux/skbuff.h>
#ifdef CONFIG_NETFILTER_DEBUG
#define IP_NF_ASSERT(x) \
do { \
if (!(x)) \
/* Wooah! I'm tripping my conntrack in a frenzy of \
netplay... */ \
printk("NF_IP_ASSERT: %s:%i(%s)\n", \
__FILE__, __LINE__, __FUNCTION__); \
} while(0)
#else
#define IP_NF_ASSERT(x)
#endif
struct ip_conntrack_helper;
struct ip_conntrack
{
/* 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;
/* Have we seen traffic both ways yet? (bitset) */
unsigned long status;
/* Timer function; drops refcnt when it goes off. */
struct timer_list timeout;
#ifdef CONFIG_IP_NF_CT_ACCT
/* 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 ip_conntrack *master;
/* Current number of expected connections */
unsigned int expecting;
/* Unique ID that identifies this conntrack*/
unsigned int id;
/* Helper, if any. */
struct ip_conntrack_helper *helper;
/* Storage reserved for other modules: */
union ip_conntrack_proto proto;
union ip_conntrack_help help;
#ifdef CONFIG_IP_NF_NAT_NEEDED
struct {
struct ip_nat_info info;
union ip_conntrack_nat_help help;
#if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
int masq_index;
#endif
} nat;
#endif /* CONFIG_IP_NF_NAT_NEEDED */
#if defined(CONFIG_IP_NF_CONNTRACK_MARK)
u_int32_t mark;
#endif
/* Traversed often, so hopefully in different cacheline to top */
/* These are my tuples; original and reply */
struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
};
struct ip_conntrack_expect
{
/* Internal linked list (global expectation list) */
struct list_head list;
/* We expect this tuple, with the following mask */
struct ip_conntrack_tuple tuple, mask;
/* Function to call after setup and insertion */
void (*expectfn)(struct ip_conntrack *new,
struct ip_conntrack_expect *this);
/* The conntrack of the master connection */
struct ip_conntrack *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_IP_NF_NAT_NEEDED
/* This is the original per-proto part, used to map the
* expected connection the way the recipient expects. */
union ip_conntrack_manip_proto saved_proto;
/* Direction relative to the master connection. */
enum ip_conntrack_dir dir;
#endif
};
#define IP_CT_EXPECT_PERMANENT 0x1
static inline struct ip_conntrack *
tuplehash_to_ctrack(const struct ip_conntrack_tuple_hash *hash)
{
return container_of(hash, struct ip_conntrack,
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
ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
const struct ip_conntrack_tuple *newreply);
/* Is this tuple taken? (ignoring any belonging to the given
conntrack). */
extern int
ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
const struct ip_conntrack *ignored_conntrack);
/* Return conntrack_info and tuple hash for given skb. */
static inline struct ip_conntrack *
ip_conntrack_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
{
*ctinfo = skb->nfctinfo;
return (struct ip_conntrack *)skb->nfct;
}
/* decrement reference count on a conntrack */
static inline void
ip_conntrack_put(struct ip_conntrack *ct)
{
IP_NF_ASSERT(ct);
nf_conntrack_put(&ct->ct_general);
}
/* call to create an explicit dependency on ip_conntrack. */
extern void need_ip_conntrack(void);
extern int invert_tuplepr(struct ip_conntrack_tuple *inverse,
const struct ip_conntrack_tuple *orig);
extern void __ip_ct_refresh_acct(struct ip_conntrack *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 ip_ct_refresh_acct(struct ip_conntrack *ct,
enum ip_conntrack_info ctinfo,
const struct sk_buff *skb,
unsigned long extra_jiffies)
{
__ip_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
}
/* Refresh conntrack for this many jiffies */
static inline void ip_ct_refresh(struct ip_conntrack *ct,
const struct sk_buff *skb,
unsigned long extra_jiffies)
{
__ip_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 ip_conntrack_tcp_update(struct sk_buff *skb,
struct ip_conntrack *conntrack,
enum ip_conntrack_dir dir);
/* Call me when a conntrack is destroyed. */
extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
/* Fake conntrack entry for untracked connections */
extern struct ip_conntrack ip_conntrack_untracked;
/* Returns new sk_buff, or NULL */
struct sk_buff *
ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user);
/* Iterate over all conntracks: if iter returns true, it's deleted. */
extern void
ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *data),
void *data);
extern struct ip_conntrack_helper *
__ip_conntrack_helper_find_byname(const char *);
extern struct ip_conntrack_helper *
ip_conntrack_helper_find_get(const struct ip_conntrack_tuple *tuple);
extern void ip_conntrack_helper_put(struct ip_conntrack_helper *helper);
extern struct ip_conntrack_protocol *
__ip_conntrack_proto_find(u_int8_t protocol);
extern struct ip_conntrack_protocol *
ip_conntrack_proto_find_get(u_int8_t protocol);
extern void ip_conntrack_proto_put(struct ip_conntrack_protocol *proto);
extern void ip_ct_remove_expectations(struct ip_conntrack *ct);
extern struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *,
struct ip_conntrack_tuple *);
extern void ip_conntrack_free(struct ip_conntrack *ct);
extern void ip_conntrack_hash_insert(struct ip_conntrack *ct);
extern struct ip_conntrack_expect *
__ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
extern struct ip_conntrack_expect *
ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
extern struct ip_conntrack_tuple_hash *
__ip_conntrack_find(const struct ip_conntrack_tuple *tuple,
const struct ip_conntrack *ignored_conntrack);
extern void ip_conntrack_flush(void);
/* It's confirmed if it is, or has been in the hash table. */
static inline int is_confirmed(struct ip_conntrack *ct)
{
return test_bit(IPS_CONFIRMED_BIT, &ct->status);
}
static inline int is_dying(struct ip_conntrack *ct)
{
return test_bit(IPS_DYING_BIT, &ct->status);
}
extern unsigned int ip_conntrack_htable_size;
#define CONNTRACK_STAT_INC(count) (__get_cpu_var(ip_conntrack_stat).count++)
#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
#include <linux/notifier.h>
#include <linux/interrupt.h>
struct ip_conntrack_ecache {
struct ip_conntrack *ct;
unsigned int events;
};
DECLARE_PER_CPU(struct ip_conntrack_ecache, ip_conntrack_ecache);
#define CONNTRACK_ECACHE(x) (__get_cpu_var(ip_conntrack_ecache).x)
extern struct notifier_block *ip_conntrack_chain;
extern struct notifier_block *ip_conntrack_expect_chain;
static inline int ip_conntrack_register_notifier(struct notifier_block *nb)
{
return notifier_chain_register(&ip_conntrack_chain, nb);
}
static inline int ip_conntrack_unregister_notifier(struct notifier_block *nb)
{
return notifier_chain_unregister(&ip_conntrack_chain, nb);
}
static inline int
ip_conntrack_expect_register_notifier(struct notifier_block *nb)
{
return notifier_chain_register(&ip_conntrack_expect_chain, nb);
}
static inline int
ip_conntrack_expect_unregister_notifier(struct notifier_block *nb)
{
return notifier_chain_unregister(&ip_conntrack_expect_chain, nb);
}
extern void ip_ct_deliver_cached_events(const struct ip_conntrack *ct);
extern void __ip_ct_event_cache_init(struct ip_conntrack *ct);
static inline void
ip_conntrack_event_cache(enum ip_conntrack_events event,
const struct sk_buff *skb)
{
struct ip_conntrack *ct = (struct ip_conntrack *)skb->nfct;
struct ip_conntrack_ecache *ecache;
local_bh_disable();
ecache = &__get_cpu_var(ip_conntrack_ecache);
if (ct != ecache->ct)
__ip_ct_event_cache_init(ct);
ecache->events |= event;
local_bh_enable();
}
static inline void ip_conntrack_event(enum ip_conntrack_events event,
struct ip_conntrack *ct)
{
if (is_confirmed(ct) && !is_dying(ct))
notifier_call_chain(&ip_conntrack_chain, event, ct);
}
static inline void
ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
struct ip_conntrack_expect *exp)
{
notifier_call_chain(&ip_conntrack_expect_chain, event, exp);
}
#else /* CONFIG_IP_NF_CONNTRACK_EVENTS */
static inline void ip_conntrack_event_cache(enum ip_conntrack_events event,
const struct sk_buff *skb) {}
static inline void ip_conntrack_event(enum ip_conntrack_events event,
struct ip_conntrack *ct) {}
static inline void ip_ct_deliver_cached_events(const struct ip_conntrack *ct) {}
static inline void
ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
struct ip_conntrack_expect *exp) {}
#endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */
#ifdef CONFIG_IP_NF_NAT_NEEDED
static inline int ip_nat_initialized(struct ip_conntrack *conntrack,
enum ip_nat_manip_type manip)
{
if (manip == IP_NAT_MANIP_SRC)
return test_bit(IPS_SRC_NAT_DONE_BIT, &conntrack->status);
return test_bit(IPS_DST_NAT_DONE_BIT, &conntrack->status);
}
#endif /* CONFIG_IP_NF_NAT_NEEDED */
#endif /* __KERNEL__ */
#endif /* _IP_CONNTRACK_H */