include/linux/netfilter_ipv4/ip_conntrack_helper.h

   1 /* IP connection tracking helpers. */
   2 #ifndef _IP_CONNTRACK_HELPER_H
   3 #define _IP_CONNTRACK_HELPER_H
   4 #include <linux/netfilter_ipv4/ip_conntrack.h>
   5
   6 struct module;
   7
   8 struct ip_conntrack_helper
   9 {
  10         struct list_head list;          /* Internal use. */
  11
  12         const char *name;               /* name of the module */
  13         struct module *me;              /* pointer to self */
  14         unsigned int max_expected;      /* Maximum number of concurrent
  15                                          * expected connections */
  16         unsigned int timeout;           /* timeout for expecteds */
  17
  18         /* Mask of things we will help (compared against server response) */
  19         struct ip_conntrack_tuple tuple;
  20         struct ip_conntrack_tuple mask;
  21
  22         /* Function to call when data passes; return verdict, or -1 to
  23            invalidate. */
  24         int (*help)(struct sk_buff **pskb,
  25                     struct ip_conntrack *ct,
  26                     enum ip_conntrack_info conntrackinfo);
  27
  28         void (*destroy)(struct ip_conntrack *ct);
  29
  30         int (*to_nfattr)(struct sk_buff *skb, const struct ip_conntrack *ct);
  31 };
  32
  33 extern int ip_conntrack_helper_register(struct ip_conntrack_helper *);
  34 extern void ip_conntrack_helper_unregister(struct ip_conntrack_helper *);
  35
  36 /* Allocate space for an expectation: this is mandatory before calling
  37    ip_conntrack_expect_related.  You will have to call put afterwards. */
  38 extern struct ip_conntrack_expect *
  39 ip_conntrack_expect_alloc(struct ip_conntrack *master);
  40 extern void ip_conntrack_expect_put(struct ip_conntrack_expect *exp);
  41
  42 /* Add an expected connection: can have more than one per connection */
  43 extern int ip_conntrack_expect_related(struct ip_conntrack_expect *exp);
  44 extern void ip_conntrack_unexpect_related(struct ip_conntrack_expect *exp);
  45
  46 #endif /*_IP_CONNTRACK_HELPER_H*/