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 19struct 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 76extern struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX]; 77 78/* Protocol registration. */ 79extern int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto); 80extern void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto); 81extern struct nf_conntrack_l3proto *nf_ct_l3proto_find_get(u_int16_t l3proto); 82extern void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p); 83 84/* Existing built-in protocols */ 85extern struct nf_conntrack_l3proto nf_conntrack_l3proto_generic; 86 87static 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*/ 96