include/net/netfilter/nf_conntrack_helper.h

   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
  15 struct module;
  16
  17 #define NF_CT_HELPER_NAME_LEN   16
  18
  19 struct nf_conntrack_helper
  20 {
  21         struct hlist_node hnode;        /* Internal use. */
  22
  23         const char *name;               /* name of the module */
  24         struct module *me;              /* pointer to self */
  25         const struct nf_conntrack_expect_policy *expect_policy;
  26
  27         /* Tuple of things we will help (compared against server response) */
  28         struct nf_conntrack_tuple tuple;
  29
  30         /* Function to call when data passes; return verdict, or -1 to
  31            invalidate. */
  32         int (*help)(struct sk_buff *skb,
  33                     unsigned int protoff,
  34                     struct nf_conn *ct,
  35                     enum ip_conntrack_info conntrackinfo);
  36
  37         void (*destroy)(struct nf_conn *ct);
  38
  39         int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
  40         unsigned int expect_class_max;
  41 };
  42
  43 extern struct nf_conntrack_helper *
  44 __nf_conntrack_helper_find_byname(const char *name);
  45
  46 extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
  47 extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
  48
  49 extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
  50
  51 extern int __nf_ct_try_assign_helper(struct nf_conn *ct, gfp_t flags);
  52
  53 extern void nf_ct_helper_destroy(struct nf_conn *ct);
  54
  55 static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
  56 {
  57         return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
  58 }
  59
  60 extern int nf_conntrack_helper_init(void);
  61 extern void nf_conntrack_helper_fini(void);
  62
  63 #endif /*_NF_CONNTRACK_HELPER_H*/