Blame |
Last modification |
View Log
| RSS feed
#ifndef _IP_CONNTRACK_H
#define _IP_CONNTRACK_H
/* Connection state tracking for netfilter. This is separated from,
but required by, the NAT layer; it can also be used by an iptables
extension. */
#include <linux/config.h>
#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <asm/atomic.h>
enum ip_conntrack_info
{
/* Part of an established connection (either direction). */
IP_CT_ESTABLISHED,
/* Like NEW, but related to an existing connection, or ICMP error
(in either direction). */
IP_CT_RELATED,
/* Started a new connection to track (only
IP_CT_DIR_ORIGINAL); may be a retransmission. */
IP_CT_NEW,
/* >= this indicates reply direction */
IP_CT_IS_REPLY,
/* Number of distinct IP_CT types (no NEW in reply dirn). */
IP_CT_NUMBER = IP_CT_IS_REPLY * 2 - 1
};
/* Bitset representing status of connection. */
enum ip_conntrack_status {
/* It's an expected connection: bit 0 set. This bit never changed */
IPS_EXPECTED_BIT = 0,
IPS_EXPECTED = (1 << IPS_EXPECTED_BIT),
/* We've seen packets both ways: bit 1 set. Can be set, not unset. */
IPS_SEEN_REPLY_BIT = 1,
IPS_SEEN_REPLY = (1 << IPS_SEEN_REPLY_BIT),
/* Conntrack should never be early-expired. */
IPS_ASSURED_BIT = 2,
IPS_ASSURED = (1 << IPS_ASSURED_BIT),
/* Connection is confirmed: originating packet has left box */
IPS_CONFIRMED_BIT = 3,
IPS_CONFIRMED = (1 << IPS_CONFIRMED_BIT),
};
#include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
#include <linux/netfilter_ipv4/ip_conntrack_icmp.h>
/* per conntrack: protocol private data */
union ip_conntrack_proto {
/* insert conntrack proto private data here */
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_amanda.h>
#include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
#include <linux/netfilter_ipv4/ip_conntrack_irc.h>
/* per expectation: application helper private data */
union ip_conntrack_expect_help {
/* insert conntrack helper private data (expect) here */
struct ip_ct_amanda_expect exp_amanda_info;
struct ip_ct_ftp_expect exp_ftp_info;
struct ip_ct_irc_expect exp_irc_info;
#ifdef CONFIG_IP_NF_NAT_NEEDED
union {
/* insert nat helper private data (expect) here */
} nat;
#endif
};
/* per conntrack: application helper private data */
union ip_conntrack_help {
/* insert conntrack helper private data (master) here */
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>
/* per conntrack: nat application helper private data */
union ip_conntrack_nat_help {
/* insert nat helper private data here */
};
#endif
#ifdef __KERNEL__
#include <linux/types.h>
#include <linux/skbuff.h>
#ifdef CONFIG_NF_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_expect
{
/* Internal linked list (global expectation list) */
struct list_head list;
/* reference count */
atomic_t use;
/* expectation list for this master */
struct list_head expected_list;
/* The conntrack of the master connection */
struct ip_conntrack *expectant;
/* The conntrack of the sibling connection, set after
* expectation arrived */
struct ip_conntrack *sibling;
/* Tuple saved for conntrack */
struct ip_conntrack_tuple ct_tuple;
/* Timer function; deletes the expectation. */
struct timer_list timeout;
/* Data filled out by the conntrack helpers follow: */
/* We expect this tuple, with the following mask */
struct ip_conntrack_tuple tuple, mask;
/* Function to call after setup and insertion */
int (*expectfn)(struct ip_conntrack *new);
/* At which sequence number did this expectation occur */
u_int32_t seq;
union ip_conntrack_expect_proto proto;
union ip_conntrack_expect_help help;
};
#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
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;
/* These are my tuples; original and reply */
struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
/* Have we seen traffic both ways yet? (bitset) */
unsigned long status;
/* Timer function; drops refcnt when it goes off. */
struct timer_list timeout;
/* If we're expecting another related connection, this will be
in expected linked list */
struct list_head sibling_list;
/* Current number of expected connections */
unsigned int expecting;
/* If we were expected by an expectation, this will be it */
struct ip_conntrack_expect *master;
/* Helper, if any. */
struct ip_conntrack_helper *helper;
/* Our various nf_ct_info structs specify *what* relation this
packet has to the conntrack */
struct nf_ct_info infos[IP_CT_NUMBER];
/* 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 */
};
/* get master conntrack via master expectation */
#define master_ct(conntr) (conntr->master ? conntr->master->expectant : NULL)
/* Alter reply tuple (maybe alter helper). If it's already taken,
return 0 and don't do alteration. */
extern int
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. */
extern struct ip_conntrack *
ip_conntrack_get(struct sk_buff *skb, enum ip_conntrack_info *ctinfo);
/* decrement reference count on a conntrack */
extern inline void ip_conntrack_put(struct ip_conntrack *ct);
/* find unconfirmed expectation based on tuple */
struct ip_conntrack_expect *
ip_conntrack_expect_find_get(const struct ip_conntrack_tuple *tuple);
/* decrement reference count on an expectation */
void ip_conntrack_expect_put(struct ip_conntrack_expect *exp);
/* 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);
/* Refresh conntrack for this many jiffies */
extern void ip_ct_refresh(struct ip_conntrack *ct,
unsigned long extra_jiffies);
/* These are for NAT. Icky. */
/* Call me when a conntrack is destroyed. */
extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
/* Returns new sk_buff, or NULL */
struct sk_buff *
ip_ct_gather_frags(struct sk_buff *skb);
/* Delete all conntracks which match. */
extern void
ip_ct_selective_cleanup(int (*kill)(const struct ip_conntrack *i, void *data),
void *data);
/* 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);
}
extern unsigned int ip_conntrack_htable_size;
/* eg. PROVIDES_CONNTRACK(ftp); */
#define PROVIDES_CONNTRACK(name) \
int needs_ip_conntrack_##name; \
EXPORT_SYMBOL(needs_ip_conntrack_##name)
/*. eg. NEEDS_CONNTRACK(ftp); */
#define NEEDS_CONNTRACK(name) \
extern int needs_ip_conntrack_##name; \
static int *need_ip_conntrack_##name __attribute_used__ = &needs_ip_conntrack_##name
#endif /* __KERNEL__ */
#endif /* _IP_CONNTRACK_H */