LXR linux/include/net/netfilter/nf_conntrack

   1/*
   2 * connection tracking helpers.
   3 *
   4 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   5 *      - generalize L3 protocol dependent part.
   6 *
   7 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
   8 */
   9
  10#ifndef _NF_CONNTRACK_HELPER_H
  11#define _NF_CONNTRACK_HELPER_H
  12#include <net/netfilter/nf_conntrack.h>
  13#include <net/netfilter/nf_conntrack_extend.h>
  14
  15struct module;
  16
  17#define NF_CT_HELPER_NAME_LEN   16
  18
  19struct nf_conntrack_helper {
  20        struct hlist_node hnode;        /* Internal use. */
  21
  22        const char *name;               /* name of the module */
  23        struct module *me;              /* pointer to self */
  24        const struct nf_conntrack_expect_policy *expect_policy;
  25
  26        /* Tuple of things we will help (compared against server response) */
  27        struct nf_conntrack_tuple tuple;
  28
  29        /* Function to call when data passes; return verdict, or -1 to
  30           invalidate. */
  31        int (*help)(struct sk_buff *skb,
  32                    unsigned int protoff,
  33                    struct nf_conn *ct,
  34                    enum ip_conntrack_info conntrackinfo);
  35
  36        void (*destroy)(struct nf_conn *ct);
  37
  38        int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
  39        unsigned int expect_class_max;
  40};
  41
  42extern struct nf_conntrack_helper *
  43__nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum);
  44
  45extern struct nf_conntrack_helper *
  46nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum);
  47
  48extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
  49extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
  50
  51extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
  52
  53extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
  54                                     gfp_t flags);
  55
  56extern void nf_ct_helper_destroy(struct nf_conn *ct);
  57
  58static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
  59{
  60        return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
  61}
  62
  63extern int nf_conntrack_helper_init(void);
  64extern void nf_conntrack_helper_fini(void);
  65
  66extern int nf_conntrack_broadcast_help(struct sk_buff *skb,
  67                                       unsigned int protoff,
  68                                       struct nf_conn *ct,
  69                                       enum ip_conntrack_info ctinfo,
  70                                       unsigned int timeout);
  71
  72#endif /*_NF_CONNTRACK_HELPER_H*/
  73