root/include/net/netfilter/nf_conntrack_helper.h

INCLUDED FROM

DEFINITIONS

1. nfct_help

/*
 * connection tracking helpers.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 *      - generalize L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
 */

#ifndef _NF_CONNTRACK_HELPER_H
#define _NF_CONNTRACK_HELPER_H
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_extend.h>

struct module;

struct nf_conntrack_helper
{
        struct hlist_node hnode;        /* Internal use. */

        const char *name;               /* name of the module */
        struct module *me;              /* pointer to self */
        const struct nf_conntrack_expect_policy *expect_policy;

        /* Tuple of things we will help (compared against server response) */
        struct nf_conntrack_tuple tuple;

        /* Function to call when data passes; return verdict, or -1 to
           invalidate. */
        int (*help)(struct sk_buff *skb,
                    unsigned int protoff,
                    struct nf_conn *ct,
                    enum ip_conntrack_info conntrackinfo);

        void (*destroy)(struct nf_conn *ct);

        int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
        unsigned int expect_class_max;
};

extern struct nf_conntrack_helper *
__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple);

extern struct nf_conntrack_helper *
__nf_conntrack_helper_find_byname(const char *name);

extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);

extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);

static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{
        return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
}

extern int nf_conntrack_helper_init(void);
extern void nf_conntrack_helper_fini(void);

#endif /*_NF_CONNTRACK_HELPER_H*/