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/*
* Copyright (C)2003,2004 USAGI/WIDE Project
*
* Header for use in defining a given L3 protocol for connection tracking.
*
* Author:
* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
*
* Derived from include/netfilter_ipv4/ip_conntrack_protocol.h
*/
#ifndef _NF_CONNTRACK_L3PROTO_H
#define _NF_CONNTRACK_L3PROTO_H
#include <linux/netlink.h>
#include <net/netlink.h>
#include <linux/seq_file.h>
#include <net/netfilter/nf_conntrack.h>
struct nf_conntrack_l3proto {
/* L3 Protocol Family number. ex) PF_INET */
u_int16_t l3proto;
/* size of tuple nlattr, fills a hole */
u16 nla_size;
/* Protocol name */
const char *name;
/*
* Try to fill in the third arg: nhoff is offset of l3 proto
* hdr. Return true if possible.
*/
bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int nhoff,
struct nf_conntrack_tuple *tuple);
/*
* Invert the per-proto part of the tuple: ie. turn xmit into reply.
* Some packets can't be inverted: return 0 in that case.
*/
bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
const struct nf_conntrack_tuple *orig);
/* Print out the per-protocol part of the tuple. */
void (*print_tuple)(struct seq_file *s,
const struct nf_conntrack_tuple *);
/*
* Called before tracking.
* *dataoff: offset of protocol header (TCP, UDP,...) in skb
* *protonum: protocol number
*/
int (*get_l4proto)(const struct sk_buff *skb, unsigned int nhoff,
unsigned int *dataoff, u_int8_t *protonum);
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
int (*tuple_to_nlattr)(struct sk_buff *skb,
const struct nf_conntrack_tuple *t);
int (*nlattr_to_tuple)(struct nlattr *tb[],
struct nf_conntrack_tuple *t);
const struct nla_policy *nla_policy;
#endif
/* Called when netns wants to use connection tracking */
int (*net_ns_get)(struct net *);
void (*net_ns_put)(struct net *);
/* Module (if any) which this is connected to. */
struct module *me;
};
extern struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO];
/* Protocol global registration. */
int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto);
void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto);
struct nf_conntrack_l3proto *nf_ct_l3proto_find_get(u_int16_t l3proto);
/* Existing built-in protocols */
extern struct nf_conntrack_l3proto nf_conntrack_l3proto_generic;
static inline struct nf_conntrack_l3proto *
__nf_ct_l3proto_find(u_int16_t l3proto)
{
if (unlikely(l3proto >= NFPROTO_NUMPROTO))
return &nf_conntrack_l3proto_generic;
return rcu_dereference(nf_ct_l3protos[l3proto]);
}
#endif /*_NF_CONNTRACK_L3PROTO_H*/
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