kernel/linux/include/linux/netfilter_bridge/ebtables.h - external/ebtables - Gitiles

 /*
  *  ebtables
  *
  *	Authors:
  *	Bart De Schuymer		<bart.de.schuymer@pandora.be>
  *
  *  ebtables.c,v 2.0, September, 2002
  *
  *  This code is stongly inspired on the iptables code which is
  *  Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
  */

 #ifndef __LINUX_BRIDGE_EFF_H
 #define __LINUX_BRIDGE_EFF_H
 #include <linux/if.h>
 #include <linux/netfilter_bridge.h>
 #include <linux/if_ether.h>

 #define EBT_TABLE_MAXNAMELEN 32
 #define EBT_CHAIN_MAXNAMELEN EBT_TABLE_MAXNAMELEN
 #define EBT_FUNCTION_MAXNAMELEN EBT_TABLE_MAXNAMELEN

 // verdicts >0 are "branches"
 #define EBT_ACCEPT   -1
 #define EBT_DROP     -2
 #define EBT_CONTINUE -3
 #define EBT_RETURN   -4
 #define NUM_STANDARD_TARGETS   4

 struct ebt_counter
 {
 	uint64_t pcnt;
 	uint64_t bcnt;
 };

 struct ebt_entries {
 	// this field is always set to zero
 	// See EBT_ENTRY_OR_ENTRIES.
 	// Must be same size as ebt_entry.bitmask
 	unsigned int distinguisher;
 	// the chain name
 	char name[EBT_CHAIN_MAXNAMELEN];
 	// counter offset for this chain
 	unsigned int counter_offset;
 	// one standard (accept, drop, return) per hook
 	int policy;
 	// nr. of entries
 	unsigned int nentries;
 	// entry list
 	char data[0];
 };

 // used for the bitmask of struct ebt_entry

 // This is a hack to make a difference between an ebt_entry struct and an
 // ebt_entries struct when traversing the entries from start to end.
 // Using this simplifies the code alot, while still being able to use
 // ebt_entries.
 // Contrary, iptables doesn't use something like ebt_entries and therefore uses
 // different techniques for naming the policy and such. So, iptables doesn't
 // need a hack like this.
 #define EBT_ENTRY_OR_ENTRIES 0x01
 // these are the normal masks
 #define EBT_NOPROTO 0x02
 #define EBT_802_3 0x04
 #define EBT_SOURCEMAC 0x08
 #define EBT_DESTMAC 0x10
 #define EBT_F_MASK (EBT_NOPROTO | EBT_802_3 | EBT_SOURCEMAC | EBT_DESTMAC \
    | EBT_ENTRY_OR_ENTRIES)

 #define EBT_IPROTO 0x01
 #define EBT_IIN 0x02
 #define EBT_IOUT 0x04
 #define EBT_ISOURCE 0x8
 #define EBT_IDEST 0x10
 #define EBT_ILOGICALIN 0x20
 #define EBT_ILOGICALOUT 0x40
 #define EBT_INV_MASK (EBT_IPROTO | EBT_IIN | EBT_IOUT | EBT_ILOGICALIN \
    | EBT_ILOGICALOUT | EBT_ISOURCE | EBT_IDEST)

 struct ebt_entry_match
 {
 	union {
 		char name[EBT_FUNCTION_MAXNAMELEN];
 		struct ebt_match *match;
 	} u;
 	// size of data
 	unsigned int match_size;
 	unsigned char data[0];
 };

 struct ebt_entry_watcher
 {
 	union {
 		char name[EBT_FUNCTION_MAXNAMELEN];
 		struct ebt_watcher *watcher;
 	} u;
 	// size of data
 	unsigned int watcher_size;
 	unsigned char data[0];
 };

 struct ebt_entry_target
 {
 	union {
 		char name[EBT_FUNCTION_MAXNAMELEN];
 		struct ebt_target *target;
 	} u;
 	// size of data
 	unsigned int target_size;
 	unsigned char data[0];
 };

 #define EBT_STANDARD_TARGET "standard"
 struct ebt_standard_target
 {
 	struct ebt_entry_target target;
 	int verdict;
 };

 // one entry
 struct ebt_entry {
 	// this needs to be the first field
 	unsigned int bitmask;
 	unsigned int invflags;
 	uint16_t ethproto;
 	// the physical in-dev
 	char in[IFNAMSIZ];
 	// the logical in-dev
 	char logical_in[IFNAMSIZ];
 	// the physical out-dev
 	char out[IFNAMSIZ];
 	// the logical out-dev
 	char logical_out[IFNAMSIZ];
 	unsigned char sourcemac[ETH_ALEN];
 	unsigned char sourcemsk[ETH_ALEN];
 	unsigned char destmac[ETH_ALEN];
 	unsigned char destmsk[ETH_ALEN];
 	// sizeof ebt_entry + matches
 	unsigned int watchers_offset;
 	// sizeof ebt_entry + matches + watchers
 	unsigned int target_offset;
 	// sizeof ebt_entry + matches + watchers + target
 	unsigned int next_offset;
 	unsigned char elems[0];
 };

 struct ebt_replace
 {
 	char name[EBT_TABLE_MAXNAMELEN];
 	unsigned int valid_hooks;
 	// nr of rules in the table
 	unsigned int nentries;
 	// total size of the entries
 	unsigned int entries_size;
 	// start of the chains
 	struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
 	// nr of counters userspace expects back
 	unsigned int num_counters;
 	// where the kernel will put the old counters
 	struct ebt_counter *counters;
 	char *entries;
 };

 // [gs]etsockopt numbers
 #define EBT_BASE_CTL            128

 #define EBT_SO_SET_ENTRIES      (EBT_BASE_CTL)
 #define EBT_SO_SET_COUNTERS     (EBT_SO_SET_ENTRIES+1)
 #define EBT_SO_SET_MAX          (EBT_SO_SET_COUNTERS+1)

 #define EBT_SO_GET_INFO         (EBT_BASE_CTL)
 #define EBT_SO_GET_ENTRIES      (EBT_SO_GET_INFO+1)
 #define EBT_SO_GET_INIT_INFO    (EBT_SO_GET_ENTRIES+1)
 #define EBT_SO_GET_INIT_ENTRIES (EBT_SO_GET_INIT_INFO+1)
 #define EBT_SO_GET_MAX          (EBT_SO_GET_INIT_ENTRIES+1)

 #ifdef __KERNEL__

 // return values for match() functions
 #define EBT_MATCH 0
 #define EBT_NOMATCH 1

 struct ebt_match
 {
 	struct list_head list;
 	const char name[EBT_FUNCTION_MAXNAMELEN];
 	// 0 == it matches
 	int (*match)(const struct sk_buff *skb, const struct net_device *in,
 	   const struct net_device *out, const void *matchdata,
 	   unsigned int datalen);
 	// 0 == let it in
 	int (*check)(const char *tablename, unsigned int hookmask,
 	   const struct ebt_entry *e, void *matchdata, unsigned int datalen);
 	void (*destroy)(void *matchdata, unsigned int datalen);
 	struct module *me;
 };

 struct ebt_watcher
 {
 	struct list_head list;
 	const char name[EBT_FUNCTION_MAXNAMELEN];
 	void (*watcher)(const struct sk_buff *skb, const struct net_device *in,
 	   const struct net_device *out, const void *watcherdata,
 	   unsigned int datalen);
 	// 0 == let it in
 	int (*check)(const char *tablename, unsigned int hookmask,
 	   const struct ebt_entry *e, void *watcherdata, unsigned int datalen);
 	void (*destroy)(void *watcherdata, unsigned int datalen);
 	struct module *me;
 };

 struct ebt_target
 {
 	struct list_head list;
 	const char name[EBT_FUNCTION_MAXNAMELEN];
 	// returns one of the standard verdicts
 	int (*target)(struct sk_buff **pskb, unsigned int hooknr,
 	   const struct net_device *in, const struct net_device *out,
 	   const void *targetdata, unsigned int datalen);
 	// 0 == let it in
 	int (*check)(const char *tablename, unsigned int hookmask,
 	   const struct ebt_entry *e, void *targetdata, unsigned int datalen);
 	void (*destroy)(void *targetdata, unsigned int datalen);
 	struct module *me;
 };

 // used for jumping from and into user defined chains (udc)
 struct ebt_chainstack
 {
 	struct ebt_entries *chaininfo; // pointer to chain data
 	struct ebt_entry *e; // pointer to entry data
 	unsigned int n; // n'th entry
 };

 struct ebt_table_info
 {
 	// total size of the entries
 	unsigned int entries_size;
 	unsigned int nentries;
 	// pointers to the start of the chains
 	struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
 	// room to maintain the stack used for jumping from and into udc
 	struct ebt_chainstack **chainstack;
 	char *entries;
 	struct ebt_counter counters[0] ____cacheline_aligned;
 };

 struct ebt_table
 {
 	struct list_head list;
 	char name[EBT_TABLE_MAXNAMELEN];
 	struct ebt_replace *table;
 	unsigned int valid_hooks;
 	rwlock_t lock;
 	// e.g. could be the table explicitly only allows certain
 	// matches, targets, ... 0 == let it in
 	int (*check)(const struct ebt_table_info *info,
 	   unsigned int valid_hooks);
 	// the data used by the kernel
 	struct ebt_table_info *private;
 };

 #define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_entry_target)-1)) & \
 		     ~(__alignof__(struct ebt_entry_target)-1))
 extern int ebt_register_table(struct ebt_table *table);
 extern void ebt_unregister_table(struct ebt_table *table);
 extern int ebt_register_match(struct ebt_match *match);
 extern void ebt_unregister_match(struct ebt_match *match);
 extern int ebt_register_watcher(struct ebt_watcher *watcher);
 extern void ebt_unregister_watcher(struct ebt_watcher *watcher);
 extern int ebt_register_target(struct ebt_target *target);
 extern void ebt_unregister_target(struct ebt_target *target);
 extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff **pskb,
    const struct net_device *in, const struct net_device *out,
    struct ebt_table *table);

    // Used in the kernel match() functions
 #define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
 // True if the hook mask denotes that the rule is in a base chain,
 // used in the check() functions
 #define BASE_CHAIN (hookmask & (1 << NF_BR_NUMHOOKS))
 // Clear the bit in the hook mask that tells if the rule is on a base chain
 #define CLEAR_BASE_CHAIN_BIT (hookmask &= ~(1 << NF_BR_NUMHOOKS))
 // True if the target is not a standard target
 #define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0)

 #endif /* __KERNEL__ */

 // blatently stolen from ip_tables.h
 // fn returns 0 to continue iteration
 #define EBT_MATCH_ITERATE(e, fn, args...)                   \
 ({                                                          \
 	unsigned int __i;                                   \
 	int __ret = 0;                                      \
 	struct ebt_entry_match *__match;                    \
 	                                                    \
 	for (__i = sizeof(struct ebt_entry);                \
 	     __i < (e)->watchers_offset;                    \
 	     __i += __match->match_size +                   \
 	     sizeof(struct ebt_entry_match)) {              \
 		__match = (void *)(e) + __i;                \
 		                                            \
 		__ret = fn(__match , ## args);              \
 		if (__ret != 0)                             \
 			break;                              \
 	}                                                   \
 	if (__ret == 0) {                                   \
 		if (__i != (e)->watchers_offset)            \
 			__ret = -EINVAL;                    \
 	}                                                   \
 	__ret;                                              \
 })

 #define EBT_WATCHER_ITERATE(e, fn, args...)                 \
 ({                                                          \
 	unsigned int __i;                                   \
 	int __ret = 0;                                      \
 	struct ebt_entry_watcher *__watcher;                \
 	                                                    \
 	for (__i = e->watchers_offset;                      \
 	     __i < (e)->target_offset;                      \
 	     __i += __watcher->watcher_size +               \
 	     sizeof(struct ebt_entry_watcher)) {            \
 		__watcher = (void *)(e) + __i;              \
 		                                            \
 		__ret = fn(__watcher , ## args);            \
 		if (__ret != 0)                             \
 			break;                              \
 	}                                                   \
 	if (__ret == 0) {                                   \
 		if (__i != (e)->target_offset)              \
 			__ret = -EINVAL;                    \
 	}                                                   \
 	__ret;                                              \
 })

 #define EBT_ENTRY_ITERATE(entries, size, fn, args...)       \
 ({                                                          \
 	unsigned int __i;                                   \
 	int __ret = 0;                                      \
 	struct ebt_entry *__entry;                          \
 	                                                    \
 	for (__i = 0; __i < (size);) {                      \
 		__entry = (void *)(entries) + __i;          \
 		__ret = fn(__entry , ## args);              \
 		if (__ret != 0)                             \
 			break;                              \
 		if (__entry->bitmask != 0)                  \
 			__i += __entry->next_offset;        \
 		else                                        \
 			__i += sizeof(struct ebt_entries);  \
 	}                                                   \
 	if (__ret == 0) {                                   \
 		if (__i != (size))                          \
 			__ret = -EINVAL;                    \
 	}                                                   \
 	__ret;                                              \
 })

 #endif
	/*
	* ebtables
	*
	* Authors:
	* Bart De Schuymer <bart.de.schuymer@pandora.be>
	*
	* ebtables.c,v 2.0, September, 2002
	*
	* This code is stongly inspired on the iptables code which is
	* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
	*/

	#ifndef __LINUX_BRIDGE_EFF_H
	#define __LINUX_BRIDGE_EFF_H
	#include <linux/if.h>
	#include <linux/netfilter_bridge.h>
	#include <linux/if_ether.h>

	#define EBT_TABLE_MAXNAMELEN 32
	#define EBT_CHAIN_MAXNAMELEN EBT_TABLE_MAXNAMELEN
	#define EBT_FUNCTION_MAXNAMELEN EBT_TABLE_MAXNAMELEN

	// verdicts >0 are "branches"
	#define EBT_ACCEPT -1
	#define EBT_DROP -2
	#define EBT_CONTINUE -3
	#define EBT_RETURN -4
	#define NUM_STANDARD_TARGETS 4

	struct ebt_counter
	{
	uint64_t pcnt;
	uint64_t bcnt;
	};

	struct ebt_entries {
	// this field is always set to zero
	// See EBT_ENTRY_OR_ENTRIES.
	// Must be same size as ebt_entry.bitmask
	unsigned int distinguisher;
	// the chain name
	char name[EBT_CHAIN_MAXNAMELEN];
	// counter offset for this chain
	unsigned int counter_offset;
	// one standard (accept, drop, return) per hook
	int policy;
	// nr. of entries
	unsigned int nentries;
	// entry list
	char data[0];
	};

	// used for the bitmask of struct ebt_entry

	// This is a hack to make a difference between an ebt_entry struct and an
	// ebt_entries struct when traversing the entries from start to end.
	// Using this simplifies the code alot, while still being able to use
	// ebt_entries.
	// Contrary, iptables doesn't use something like ebt_entries and therefore uses
	// different techniques for naming the policy and such. So, iptables doesn't
	// need a hack like this.
	#define EBT_ENTRY_OR_ENTRIES 0x01
	// these are the normal masks
	#define EBT_NOPROTO 0x02
	#define EBT_802_3 0x04
	#define EBT_SOURCEMAC 0x08
	#define EBT_DESTMAC 0x10
	#define EBT_F_MASK (EBT_NOPROTO \| EBT_802_3 \| EBT_SOURCEMAC \| EBT_DESTMAC \
	\| EBT_ENTRY_OR_ENTRIES)

	#define EBT_IPROTO 0x01
	#define EBT_IIN 0x02
	#define EBT_IOUT 0x04
	#define EBT_ISOURCE 0x8
	#define EBT_IDEST 0x10
	#define EBT_ILOGICALIN 0x20
	#define EBT_ILOGICALOUT 0x40
	#define EBT_INV_MASK (EBT_IPROTO \| EBT_IIN \| EBT_IOUT \| EBT_ILOGICALIN \
	\| EBT_ILOGICALOUT \| EBT_ISOURCE \| EBT_IDEST)

	struct ebt_entry_match
	{
	union {
	char name[EBT_FUNCTION_MAXNAMELEN];
	struct ebt_match *match;
	} u;
	// size of data
	unsigned int match_size;
	unsigned char data[0];
	};

	struct ebt_entry_watcher
	{
	union {
	char name[EBT_FUNCTION_MAXNAMELEN];
	struct ebt_watcher *watcher;
	} u;
	// size of data
	unsigned int watcher_size;
	unsigned char data[0];
	};

	struct ebt_entry_target
	{
	union {
	char name[EBT_FUNCTION_MAXNAMELEN];
	struct ebt_target *target;
	} u;
	// size of data
	unsigned int target_size;
	unsigned char data[0];
	};

	#define EBT_STANDARD_TARGET "standard"
	struct ebt_standard_target
	{
	struct ebt_entry_target target;
	int verdict;
	};

	// one entry
	struct ebt_entry {
	// this needs to be the first field
	unsigned int bitmask;
	unsigned int invflags;
	uint16_t ethproto;
	// the physical in-dev
	char in[IFNAMSIZ];
	// the logical in-dev
	char logical_in[IFNAMSIZ];
	// the physical out-dev
	char out[IFNAMSIZ];
	// the logical out-dev
	char logical_out[IFNAMSIZ];
	unsigned char sourcemac[ETH_ALEN];
	unsigned char sourcemsk[ETH_ALEN];
	unsigned char destmac[ETH_ALEN];
	unsigned char destmsk[ETH_ALEN];
	// sizeof ebt_entry + matches
	unsigned int watchers_offset;
	// sizeof ebt_entry + matches + watchers
	unsigned int target_offset;
	// sizeof ebt_entry + matches + watchers + target
	unsigned int next_offset;
	unsigned char elems[0];
	};

	struct ebt_replace
	{
	char name[EBT_TABLE_MAXNAMELEN];
	unsigned int valid_hooks;
	// nr of rules in the table
	unsigned int nentries;
	// total size of the entries
	unsigned int entries_size;
	// start of the chains
	struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
	// nr of counters userspace expects back
	unsigned int num_counters;
	// where the kernel will put the old counters
	struct ebt_counter *counters;
	char *entries;
	};

	// [gs]etsockopt numbers
	#define EBT_BASE_CTL 128

	#define EBT_SO_SET_ENTRIES (EBT_BASE_CTL)
	#define EBT_SO_SET_COUNTERS (EBT_SO_SET_ENTRIES+1)
	#define EBT_SO_SET_MAX (EBT_SO_SET_COUNTERS+1)

	#define EBT_SO_GET_INFO (EBT_BASE_CTL)
	#define EBT_SO_GET_ENTRIES (EBT_SO_GET_INFO+1)
	#define EBT_SO_GET_INIT_INFO (EBT_SO_GET_ENTRIES+1)
	#define EBT_SO_GET_INIT_ENTRIES (EBT_SO_GET_INIT_INFO+1)
	#define EBT_SO_GET_MAX (EBT_SO_GET_INIT_ENTRIES+1)

	#ifdef __KERNEL__

	// return values for match() functions
	#define EBT_MATCH 0
	#define EBT_NOMATCH 1

	struct ebt_match
	{
	struct list_head list;
	const char name[EBT_FUNCTION_MAXNAMELEN];
	// 0 == it matches
	int (match)(const struct sk_buff skb, const struct net_device *in,
	const struct net_device out, const void matchdata,
	unsigned int datalen);
	// 0 == let it in
	int (check)(const char tablename, unsigned int hookmask,
	const struct ebt_entry e, void matchdata, unsigned int datalen);
	void (destroy)(void matchdata, unsigned int datalen);
	struct module *me;
	};

	struct ebt_watcher
	{
	struct list_head list;
	const char name[EBT_FUNCTION_MAXNAMELEN];
	void (watcher)(const struct sk_buff skb, const struct net_device *in,
	const struct net_device out, const void watcherdata,
	unsigned int datalen);
	// 0 == let it in
	int (check)(const char tablename, unsigned int hookmask,
	const struct ebt_entry e, void watcherdata, unsigned int datalen);
	void (destroy)(void watcherdata, unsigned int datalen);
	struct module *me;
	};

	struct ebt_target
	{
	struct list_head list;
	const char name[EBT_FUNCTION_MAXNAMELEN];
	// returns one of the standard verdicts
	int (target)(struct sk_buff *pskb, unsigned int hooknr,
	const struct net_device in, const struct net_device out,
	const void *targetdata, unsigned int datalen);
	// 0 == let it in
	int (check)(const char tablename, unsigned int hookmask,
	const struct ebt_entry e, void targetdata, unsigned int datalen);
	void (destroy)(void targetdata, unsigned int datalen);
	struct module *me;
	};

	// used for jumping from and into user defined chains (udc)
	struct ebt_chainstack
	{
	struct ebt_entries *chaininfo; // pointer to chain data
	struct ebt_entry *e; // pointer to entry data
	unsigned int n; // n'th entry
	};

	struct ebt_table_info
	{
	// total size of the entries
	unsigned int entries_size;
	unsigned int nentries;
	// pointers to the start of the chains
	struct ebt_entries *hook_entry[NF_BR_NUMHOOKS];
	// room to maintain the stack used for jumping from and into udc
	struct ebt_chainstack **chainstack;
	char *entries;
	struct ebt_counter counters[0] ____cacheline_aligned;
	};

	struct ebt_table
	{
	struct list_head list;
	char name[EBT_TABLE_MAXNAMELEN];
	struct ebt_replace *table;
	unsigned int valid_hooks;
	rwlock_t lock;
	// e.g. could be the table explicitly only allows certain
	// matches, targets, ... 0 == let it in
	int (check)(const struct ebt_table_info info,
	unsigned int valid_hooks);
	// the data used by the kernel
	struct ebt_table_info *private;
	};

	#define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_entry_target)-1)) & \
	~(__alignof__(struct ebt_entry_target)-1))
	extern int ebt_register_table(struct ebt_table *table);
	extern void ebt_unregister_table(struct ebt_table *table);
	extern int ebt_register_match(struct ebt_match *match);
	extern void ebt_unregister_match(struct ebt_match *match);
	extern int ebt_register_watcher(struct ebt_watcher *watcher);
	extern void ebt_unregister_watcher(struct ebt_watcher *watcher);
	extern int ebt_register_target(struct ebt_target *target);
	extern void ebt_unregister_target(struct ebt_target *target);
	extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff **pskb,
	const struct net_device in, const struct net_device out,
	struct ebt_table *table);

	// Used in the kernel match() functions
	#define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
	// True if the hook mask denotes that the rule is in a base chain,
	// used in the check() functions
	#define BASE_CHAIN (hookmask & (1 << NF_BR_NUMHOOKS))
	// Clear the bit in the hook mask that tells if the rule is on a base chain
	#define CLEAR_BASE_CHAIN_BIT (hookmask &= ~(1 << NF_BR_NUMHOOKS))
	// True if the target is not a standard target
	#define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS \|\| info->target >= 0)

	#endif /* __KERNEL__ */

	// blatently stolen from ip_tables.h
	// fn returns 0 to continue iteration
	#define EBT_MATCH_ITERATE(e, fn, args...) \
	({ \
	unsigned int __i; \
	int __ret = 0; \
	struct ebt_entry_match *__match; \
	\
	for (__i = sizeof(struct ebt_entry); \
	__i < (e)->watchers_offset; \
	__i += __match->match_size + \
	sizeof(struct ebt_entry_match)) { \
	__match = (void *)(e) + __i; \
	\
	__ret = fn(__match , ## args); \
	if (__ret != 0) \
	break; \
	} \
	if (__ret == 0) { \
	if (__i != (e)->watchers_offset) \
	__ret = -EINVAL; \
	} \
	__ret; \
	})

	#define EBT_WATCHER_ITERATE(e, fn, args...) \
	({ \
	unsigned int __i; \
	int __ret = 0; \
	struct ebt_entry_watcher *__watcher; \
	\
	for (__i = e->watchers_offset; \
	__i < (e)->target_offset; \
	__i += __watcher->watcher_size + \
	sizeof(struct ebt_entry_watcher)) { \
	__watcher = (void *)(e) + __i; \
	\
	__ret = fn(__watcher , ## args); \
	if (__ret != 0) \
	break; \
	} \
	if (__ret == 0) { \
	if (__i != (e)->target_offset) \
	__ret = -EINVAL; \
	} \
	__ret; \
	})

	#define EBT_ENTRY_ITERATE(entries, size, fn, args...) \
	({ \
	unsigned int __i; \
	int __ret = 0; \
	struct ebt_entry *__entry; \
	\
	for (__i = 0; __i < (size);) { \
	__entry = (void *)(entries) + __i; \
	__ret = fn(__entry , ## args); \
	if (__ret != 0) \
	break; \
	if (__entry->bitmask != 0) \
	__i += __entry->next_offset; \
	else \
	__i += sizeof(struct ebt_entries); \
	} \
	if (__ret == 0) { \
	if (__i != (size)) \
	__ret = -EINVAL; \
	} \
	__ret; \
	})

	#endif