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/seq_file.h> 15#include <net/netfilter/nf_conntrack.h> 16 17struct nfattr; 18 19struct nf_conntrack_l3proto 20{ 21 /* L3 Protocol Family number. ex) PF_INET */ 22 u_int16_t l3proto; 23 24 /* Protocol name */ 25 const char *name; 26 27 /* 28 * Try to fill in the third arg: nhoff is offset of l3 proto 29 * hdr. Return true if possible. 30 */ 31 int (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int nhoff, 32 struct nf_conntrack_tuple *tuple); 33 34 /* 35 * Invert the per-proto part of the tuple: ie. turn xmit into reply. 36 * Some packets can't be inverted: return 0 in that case. 37 */ 38 int (*invert_tuple)(struct nf_conntrack_tuple *inverse, 39 const struct nf_conntrack_tuple *orig); 40 41 /* Print out the per-protocol part of the tuple. */ 42 int (*print_tuple)(struct seq_file *s, 43 const struct nf_conntrack_tuple *); 44 45 /* Print out the private part of the conntrack. */ 46 int (*print_conntrack)(struct seq_file *s, const struct nf_conn *); 47 48 /* Returns verdict for packet, or -1 for invalid. */ 49 int (*packet)(struct nf_conn *conntrack, 50 const struct sk_buff *skb, 51 enum ip_conntrack_info ctinfo); 52 53 /* 54 * Called when a new connection for this protocol found; 55 * returns TRUE if it's OK. If so, packet() called next. 56 */ 57 int (*new)(struct nf_conn *conntrack, const struct sk_buff *skb); 58 59 /* 60 * Called before tracking. 61 * *dataoff: offset of protocol header (TCP, UDP,...) in *pskb 62 * *protonum: protocol number 63 */ 64 int (*prepare)(struct sk_buff **pskb, unsigned int hooknum, 65 unsigned int *dataoff, u_int8_t *protonum); 66 67 u_int32_t (*get_features)(const struct nf_conntrack_tuple *tuple); 68 69 int (*tuple_to_nfattr)(struct sk_buff *skb, 70 const struct nf_conntrack_tuple *t); 71 72 int (*nfattr_to_tuple)(struct nfattr *tb[], 73 struct nf_conntrack_tuple *t); 74 75#ifdef CONFIG_SYSCTL 76 struct ctl_table_header *ctl_table_header; 77 struct ctl_table *ctl_table_path; 78 struct ctl_table *ctl_table; 79#endif /* CONFIG_SYSCTL */ 80 81 /* Module (if any) which this is connected to. */ 82 struct module *me; 83}; 84 85extern struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX]; 86 87/* Protocol registration. */ 88extern int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto); 89extern void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto); 90extern struct nf_conntrack_l3proto *nf_ct_l3proto_find_get(u_int16_t l3proto); 91extern void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p); 92 93/* Existing built-in protocols */ 94extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4; 95extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6; 96extern struct nf_conntrack_l3proto nf_conntrack_l3proto_generic; 97 98static inline struct nf_conntrack_l3proto * 99__nf_ct_l3proto_find(u_int16_t l3proto) 100{ 101 if (unlikely(l3proto >= AF_MAX)) 102 return &nf_conntrack_l3proto_generic; 103 return rcu_dereference(nf_ct_l3protos[l3proto]); 104} 105 106#endif /*_NF_CONNTRACK_L3PROTO_H*/ 107