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#include <net/netfilter/nf_conntrack_expect.h>
  15
  16struct module;
  17
  18enum nf_ct_helper_flags {
  19        NF_CT_HELPER_F_USERSPACE        = (1 << 0),
  20        NF_CT_HELPER_F_CONFIGURED       = (1 << 1),
  21};
  22
  23#define NF_CT_HELPER_NAME_LEN   16
  24
  25struct nf_conntrack_helper {
  26        struct hlist_node hnode;        /* Internal use. */
  27
  28        char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */
  29        struct module *me;              /* pointer to self */
  30        const struct nf_conntrack_expect_policy *expect_policy;
  31
  32        /* length of internal data, ie. sizeof(struct nf_ct_*_master) */
  33        size_t data_len;
  34
  35        /* Tuple of things we will help (compared against server response) */
  36        struct nf_conntrack_tuple tuple;
  37
  38        /* Function to call when data passes; return verdict, or -1 to
  39           invalidate. */
  40        int (*help)(struct sk_buff *skb,
  41                    unsigned int protoff,
  42                    struct nf_conn *ct,
  43                    enum ip_conntrack_info conntrackinfo);
  44
  45        void (*destroy)(struct nf_conn *ct);
  46
  47        int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
  48        int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
  49        unsigned int expect_class_max;
  50
  51        unsigned int flags;
  52        unsigned int queue_num;         /* For user-space helpers. */
  53};
  54
  55struct nf_conntrack_helper *__nf_conntrack_helper_find(const char *name,
  56                                                       u16 l3num, u8 protonum);
  57
  58struct nf_conntrack_helper *nf_conntrack_helper_try_module_get(const char *name,
  59                                                               u16 l3num,
  60                                                               u8 protonum);
  61
  62int nf_conntrack_helper_register(struct nf_conntrack_helper *);
  63void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
  64
  65struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct,
  66                                          struct nf_conntrack_helper *helper,
  67                                          gfp_t gfp);
  68
  69int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
  70                              gfp_t flags);
  71
  72void nf_ct_helper_destroy(struct nf_conn *ct);
  73
  74static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
  75{
  76        return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
  77}
  78
  79static inline void *nfct_help_data(const struct nf_conn *ct)
  80{
  81        struct nf_conn_help *help;
  82
  83        help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
  84
  85        return (void *)help->data;
  86}
  87
  88int nf_conntrack_helper_pernet_init(struct net *net);
  89void nf_conntrack_helper_pernet_fini(struct net *net);
  90
  91int nf_conntrack_helper_init(void);
  92void nf_conntrack_helper_fini(void);
  93
  94int nf_conntrack_broadcast_help(struct sk_buff *skb, unsigned int protoff,
  95                                struct nf_conn *ct,
  96                                enum ip_conntrack_info ctinfo,
  97                                unsigned int timeout);
  98
  99struct nf_ct_helper_expectfn {
 100        struct list_head head;
 101        const char *name;
 102        void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
 103};
 104
 105__printf(3,4)
 106void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct,
 107                      const char *fmt, ...);
 108
 109void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n);
 110void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n);
 111struct nf_ct_helper_expectfn *
 112nf_ct_helper_expectfn_find_by_name(const char *name);
 113struct nf_ct_helper_expectfn *
 114nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
 115
 116extern struct hlist_head *nf_ct_helper_hash;
 117extern unsigned int nf_ct_helper_hsize;
 118
 119#endif /*_NF_CONNTRACK_HELPER_H*/
 120