release/src-rt-6.x.4708/linux/linux-2.6.36/include/net/netfilter/nf_conntrack_l3proto.h

   1 /*
   2  * Copyright (C)2003,2004 USAGI/WIDE Project
   3  *
   4  * Header for use in defining a given L3 protocol for connection tracking.
   5  *
   6  * Author:
   7  *      Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   8  *
   9  * Derived from include/netfilter_ipv4/ip_conntrack_protocol.h
  10  */
  11
  12 #ifndef _NF_CONNTRACK_L3PROTO_H
  13 #define _NF_CONNTRACK_L3PROTO_H
  14 #include <linux/netlink.h>
  15 #include <net/netlink.h>
  16 #include <linux/seq_file.h>
  17 #include <net/netfilter/nf_conntrack.h>
  18
  19 struct nf_conntrack_l3proto {
  20         /* L3 Protocol Family number. ex) PF_INET */
  21         u_int16_t l3proto;
  22
  23         /* Protocol name */
  24         const char *name;
  25
  26         /*
  27          * Try to fill in the third arg: nhoff is offset of l3 proto
  28          * hdr.  Return true if possible.
  29          */
  30         bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int nhoff,
  31                              struct nf_conntrack_tuple *tuple);
  32
  33         /*
  34          * Invert the per-proto part of the tuple: ie. turn xmit into reply.
  35          * Some packets can't be inverted: return 0 in that case.
  36          */
  37         bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  38                              const struct nf_conntrack_tuple *orig);
  39
  40         /* Print out the per-protocol part of the tuple. */
  41         int (*print_tuple)(struct seq_file *s,
  42                            const struct nf_conntrack_tuple *);
  43
  44         /*
  45          * Called before tracking.
  46          *      *dataoff: offset of protocol header (TCP, UDP,...) in skb
  47          *      *protonum: protocol number
  48          */
  49         int (*get_l4proto)(const struct sk_buff *skb, unsigned int nhoff,
  50                            unsigned int *dataoff, u_int8_t *protonum);
  51
  52         int (*tuple_to_nlattr)(struct sk_buff *skb,
  53                                const struct nf_conntrack_tuple *t);
  54
  55         /*
  56          * Calculate size of tuple nlattr
  57          */
  58         int (*nlattr_tuple_size)(void);
  59
  60         int (*nlattr_to_tuple)(struct nlattr *tb[],
  61                                struct nf_conntrack_tuple *t);
  62         const struct nla_policy *nla_policy;
  63
  64         size_t nla_size;
  65
  66 #ifdef CONFIG_SYSCTL
  67         struct ctl_table_header *ctl_table_header;
  68         struct ctl_path         *ctl_table_path;
  69         struct ctl_table        *ctl_table;
  70 #endif /* CONFIG_SYSCTL */
  71
  72         /* Module (if any) which this is connected to. */
  73         struct module *me;
  74 };
  75
  76 extern struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX];
  77
  78 /* Protocol registration. */
  79 extern int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto);
  80 extern void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto);
  81 extern struct nf_conntrack_l3proto *nf_ct_l3proto_find_get(u_int16_t l3proto);
  82 extern void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p);
  83
  84 /* Existing built-in protocols */
  85 extern struct nf_conntrack_l3proto nf_conntrack_l3proto_generic;
  86
  87 static inline struct nf_conntrack_l3proto *
  88 __nf_ct_l3proto_find(u_int16_t l3proto)
  89 {
  90         if (unlikely(l3proto >= AF_MAX))
  91                 return &nf_conntrack_l3proto_generic;
  92         return rcu_dereference(nf_ct_l3protos[l3proto]);
  93 }
  94
  95 #endif /*_NF_CONNTRACK_L3PROTO_H*/