linux/include/net/netfilter/nf_conntrack_helper.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * connection tracking helpers.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <[email protected]>
 *	- generalize L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
 */

#ifndef _NF_CONNTRACK_HELPER_H
#define _NF_CONNTRACK_HELPER_H
#include <linux/refcount.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_expect.h>

#define NF_NAT_HELPER_PREFIX …
#define NF_NAT_HELPER_NAME(name) …
#define MODULE_ALIAS_NF_NAT_HELPER(name) …

struct module;

enum nf_ct_helper_flags { … };

#define NF_CT_HELPER_NAME_LEN …

struct nf_conntrack_helper { … };

/* Must be kept in sync with the classes defined by helpers */
#define NF_CT_MAX_EXPECT_CLASSES …

/* nf_conn feature for connections that have a helper */
struct nf_conn_help { … };

#define NF_CT_HELPER_BUILD_BUG_ON(structsize) …

struct nf_conntrack_helper *__nf_conntrack_helper_find(const char *name,
						       u16 l3num, u8 protonum);

struct nf_conntrack_helper *nf_conntrack_helper_try_module_get(const char *name,
							       u16 l3num,
							       u8 protonum);
void nf_conntrack_helper_put(struct nf_conntrack_helper *helper);

void nf_ct_helper_init(struct nf_conntrack_helper *helper,
		       u16 l3num, u16 protonum, const char *name,
		       u16 default_port, u16 spec_port, u32 id,
		       const struct nf_conntrack_expect_policy *exp_pol,
		       u32 expect_class_max,
		       int (*help)(struct sk_buff *skb, unsigned int protoff,
				   struct nf_conn *ct,
				   enum ip_conntrack_info ctinfo),
		       int (*from_nlattr)(struct nlattr *attr,
					  struct nf_conn *ct),
		       struct module *module);

int nf_conntrack_helper_register(struct nf_conntrack_helper *);
void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);

int nf_conntrack_helpers_register(struct nf_conntrack_helper *, unsigned int);
void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *,
				     unsigned int);

struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);

int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
			      gfp_t flags);

int nf_ct_helper(struct sk_buff *skb, struct nf_conn *ct,
		 enum ip_conntrack_info ctinfo, u16 proto);
int nf_ct_add_helper(struct nf_conn *ct, const char *name, u8 family,
		     u8 proto, bool nat, struct nf_conntrack_helper **hp);

void nf_ct_helper_destroy(struct nf_conn *ct);

static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{ … }

static inline void *nfct_help_data(const struct nf_conn *ct)
{ … }

int nf_conntrack_helper_init(void);
void nf_conntrack_helper_fini(void);

int nf_conntrack_broadcast_help(struct sk_buff *skb, struct nf_conn *ct,
				enum ip_conntrack_info ctinfo,
				unsigned int timeout);

struct nf_ct_helper_expectfn { … };

__printf(3,4)
void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct,
		      const char *fmt, ...);

void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n);
void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_name(const char *name);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_symbol(const void *symbol);

extern struct hlist_head *nf_ct_helper_hash;
extern unsigned int nf_ct_helper_hsize;

struct nf_conntrack_nat_helper { … };

#define NF_CT_NAT_HELPER_INIT(name) …

void nf_nat_helper_register(struct nf_conntrack_nat_helper *nat);
void nf_nat_helper_unregister(struct nf_conntrack_nat_helper *nat);
int nf_nat_helper_try_module_get(const char *name, u16 l3num,
				 u8 protonum);
void nf_nat_helper_put(struct nf_conntrack_helper *helper);
#endif /*_NF_CONNTRACK_HELPER_H*/