linux/include/linux/netfilter/x_tables.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _X_TABLES_H
#define _X_TABLES_H


#include <linux/netdevice.h>
#include <linux/static_key.h>
#include <linux/netfilter.h>
#include <uapi/linux/netfilter/x_tables.h>

/* Test a struct->invflags and a boolean for inequality */
#define NF_INVF(ptr, flag, boolean)

/**
 * struct xt_action_param - parameters for matches/targets
 *
 * @match:	the match extension
 * @target:	the target extension
 * @matchinfo:	per-match data
 * @targetinfo:	per-target data
 * @state:	pointer to hook state this packet came from
 * @fragoff:	packet is a fragment, this is the data offset
 * @thoff:	position of transport header relative to skb->data
 *
 * Fields written to by extensions:
 *
 * @hotdrop:	drop packet if we had inspection problems
 */
struct xt_action_param {};

static inline struct net *xt_net(const struct xt_action_param *par)
{}

static inline struct net_device *xt_in(const struct xt_action_param *par)
{}

static inline const char *xt_inname(const struct xt_action_param *par)
{}

static inline struct net_device *xt_out(const struct xt_action_param *par)
{}

static inline const char *xt_outname(const struct xt_action_param *par)
{}

static inline unsigned int xt_hooknum(const struct xt_action_param *par)
{}

static inline u_int8_t xt_family(const struct xt_action_param *par)
{}

/**
 * struct xt_mtchk_param - parameters for match extensions'
 * checkentry functions
 *
 * @net:	network namespace through which the check was invoked
 * @table:	table the rule is tried to be inserted into
 * @entryinfo:	the family-specific rule data
 * 		(struct ipt_ip, ip6t_ip, arpt_arp or (note) ebt_entry)
 * @match:	struct xt_match through which this function was invoked
 * @matchinfo:	per-match data
 * @hook_mask:	via which hooks the new rule is reachable
 * Other fields as above.
 */
struct xt_mtchk_param {};

/**
 * struct xt_mdtor_param - match destructor parameters
 * Fields as above.
 */
struct xt_mtdtor_param {};

/**
 * struct xt_tgchk_param - parameters for target extensions'
 * checkentry functions
 *
 * @entryinfo:	the family-specific rule data
 * 		(struct ipt_entry, ip6t_entry, arpt_entry, ebt_entry)
 *
 * Other fields see above.
 */
struct xt_tgchk_param {};

/* Target destructor parameters */
struct xt_tgdtor_param {};

struct xt_match {};

/* Registration hooks for targets. */
struct xt_target {};

/* Furniture shopping... */
struct xt_table {};

#include <linux/netfilter_ipv4.h>

/* The table itself */
struct xt_table_info {};

int xt_register_target(struct xt_target *target);
void xt_unregister_target(struct xt_target *target);
int xt_register_targets(struct xt_target *target, unsigned int n);
void xt_unregister_targets(struct xt_target *target, unsigned int n);

int xt_register_match(struct xt_match *target);
void xt_unregister_match(struct xt_match *target);
int xt_register_matches(struct xt_match *match, unsigned int n);
void xt_unregister_matches(struct xt_match *match, unsigned int n);

int xt_check_entry_offsets(const void *base, const char *elems,
			   unsigned int target_offset,
			   unsigned int next_offset);

int xt_check_table_hooks(const struct xt_table_info *info, unsigned int valid_hooks);

unsigned int *xt_alloc_entry_offsets(unsigned int size);
bool xt_find_jump_offset(const unsigned int *offsets,
			 unsigned int target, unsigned int size);

int xt_check_proc_name(const char *name, unsigned int size);

int xt_check_match(struct xt_mtchk_param *, unsigned int size, u16 proto,
		   bool inv_proto);
int xt_check_target(struct xt_tgchk_param *, unsigned int size, u16 proto,
		    bool inv_proto);

int xt_match_to_user(const struct xt_entry_match *m,
		     struct xt_entry_match __user *u);
int xt_target_to_user(const struct xt_entry_target *t,
		      struct xt_entry_target __user *u);
int xt_data_to_user(void __user *dst, const void *src,
		    int usersize, int size, int aligned_size);

void *xt_copy_counters(sockptr_t arg, unsigned int len,
		       struct xt_counters_info *info);
struct xt_counters *xt_counters_alloc(unsigned int counters);

struct xt_table *xt_register_table(struct net *net,
				   const struct xt_table *table,
				   struct xt_table_info *bootstrap,
				   struct xt_table_info *newinfo);
void *xt_unregister_table(struct xt_table *table);

struct xt_table_info *xt_replace_table(struct xt_table *table,
				       unsigned int num_counters,
				       struct xt_table_info *newinfo,
				       int *error);

struct xt_match *xt_find_match(u8 af, const char *name, u8 revision);
struct xt_match *xt_request_find_match(u8 af, const char *name, u8 revision);
struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision);
int xt_find_revision(u8 af, const char *name, u8 revision, int target,
		     int *err);

struct xt_table *xt_find_table(struct net *net, u8 af, const char *name);
struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
				    const char *name);
struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af,
					    const char *name);
void xt_table_unlock(struct xt_table *t);

int xt_proto_init(struct net *net, u_int8_t af);
void xt_proto_fini(struct net *net, u_int8_t af);

struct xt_table_info *xt_alloc_table_info(unsigned int size);
void xt_free_table_info(struct xt_table_info *info);

/**
 * xt_recseq - recursive seqcount for netfilter use
 *
 * Packet processing changes the seqcount only if no recursion happened
 * get_counters() can use read_seqcount_begin()/read_seqcount_retry(),
 * because we use the normal seqcount convention :
 * Low order bit set to 1 if a writer is active.
 */
DECLARE_PER_CPU(seqcount_t, xt_recseq);

/* xt_tee_enabled - true if x_tables needs to handle reentrancy
 *
 * Enabled if current ip(6)tables ruleset has at least one -j TEE rule.
 */
extern struct static_key xt_tee_enabled;

/**
 * xt_write_recseq_begin - start of a write section
 *
 * Begin packet processing : all readers must wait the end
 * 1) Must be called with preemption disabled
 * 2) softirqs must be disabled too (or we should use this_cpu_add())
 * Returns :
 *  1 if no recursion on this cpu
 *  0 if recursion detected
 */
static inline unsigned int xt_write_recseq_begin(void)
{}

/**
 * xt_write_recseq_end - end of a write section
 * @addend: return value from previous xt_write_recseq_begin()
 *
 * End packet processing : all readers can proceed
 * 1) Must be called with preemption disabled
 * 2) softirqs must be disabled too (or we should use this_cpu_add())
 */
static inline void xt_write_recseq_end(unsigned int addend)
{}

/*
 * This helper is performance critical and must be inlined
 */
static inline unsigned long ifname_compare_aligned(const char *_a,
						   const char *_b,
						   const char *_mask)
{}

struct xt_percpu_counter_alloc_state {};

bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
			     struct xt_counters *counter);
void xt_percpu_counter_free(struct xt_counters *cnt);

static inline struct xt_counters *
xt_get_this_cpu_counter(struct xt_counters *cnt)
{}

static inline struct xt_counters *
xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu)
{}

struct nf_hook_ops *xt_hook_ops_alloc(const struct xt_table *, nf_hookfn *);

int xt_register_template(const struct xt_table *t, int(*table_init)(struct net *net));
void xt_unregister_template(const struct xt_table *t);

#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
#include <net/compat.h>

struct compat_xt_entry_match {};

struct compat_xt_entry_target {};

/* FIXME: this works only on 32 bit tasks
 * need to change whole approach in order to calculate align as function of
 * current task alignment */

struct compat_xt_counters {};

struct compat_xt_counters_info {};

struct _compat_xt_align {};

#define COMPAT_XT_ALIGN(s)

void xt_compat_lock(u_int8_t af);
void xt_compat_unlock(u_int8_t af);

int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta);
void xt_compat_flush_offsets(u_int8_t af);
int xt_compat_init_offsets(u8 af, unsigned int number);
int xt_compat_calc_jump(u_int8_t af, unsigned int offset);

int xt_compat_match_offset(const struct xt_match *match);
void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
			      unsigned int *size);
int xt_compat_match_to_user(const struct xt_entry_match *m,
			    void __user **dstptr, unsigned int *size);

int xt_compat_target_offset(const struct xt_target *target);
void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
				unsigned int *size);
int xt_compat_target_to_user(const struct xt_entry_target *t,
			     void __user **dstptr, unsigned int *size);
int xt_compat_check_entry_offsets(const void *base, const char *elems,
				  unsigned int target_offset,
				  unsigned int next_offset);

#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
#endif /* _X_TABLES_H */