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* ebtables
*
* Authors:
* Bart De Schuymer <bdschuym@pandora.be>
*
* ebtables.c,v 2.0, April, 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
/* ebtables target modules store the verdict inside an int. We can
* reclaim a part of this int for backwards compatible extensions.
* The 4 lsb are more than enough to store the verdict. */
#define EBT_VERDICT_BITS 0x0000000F
struct xt_match;
struct xt_target;
struct ebt_counter {
uint64_t pcnt;
uint64_t bcnt;
};
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 __user *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 __user *counters;
char __user *entries;
};
struct ebt_replace_kernel {
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;
};
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] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
};
/* 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 a lot, 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 xt_match *match;
} u;
/* size of data */
unsigned int match_size;
unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
};
struct ebt_entry_watcher {
union {
char name[EBT_FUNCTION_MAXNAMELEN];
struct xt_target *watcher;
} u;
/* size of data */
unsigned int watcher_size;
unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
};
struct ebt_entry_target {
union {
char name[EBT_FUNCTION_MAXNAMELEN];
struct xt_target *target;
} u;
/* size of data */
unsigned int target_size;
unsigned char data[0] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
};
#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;
__be16 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] __attribute__ ((aligned (__alignof__(struct ebt_replace))));
};
/* {g,s}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];
bool (*match)(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop);
bool (*checkentry)(const char *table, const void *entry,
const struct xt_match *match, void *matchinfo,
unsigned int hook_mask);
void (*destroy)(const struct xt_match *match, void *matchinfo);
unsigned int matchsize;
u_int8_t revision;
u_int8_t family;
struct module *me;
};
struct ebt_watcher {
struct list_head list;
const char name[EBT_FUNCTION_MAXNAMELEN];
unsigned int (*target)(struct sk_buff *skb,
const struct net_device *in, const struct net_device *out,
unsigned int hook_num, const struct xt_target *target,
const void *targinfo);
bool (*checkentry)(const char *table, const void *entry,
const struct xt_target *target, void *targinfo,
unsigned int hook_mask);
void (*destroy)(const struct xt_target *target, void *targinfo);
unsigned int targetsize;
u_int8_t revision;
u_int8_t family;
struct module *me;
};
struct ebt_target {
struct list_head list;
const char name[EBT_FUNCTION_MAXNAMELEN];
/* returns one of the standard EBT_* verdicts */
unsigned int (*target)(struct sk_buff *skb,
const struct net_device *in, const struct net_device *out,
unsigned int hook_num, const struct xt_target *target,
const void *targinfo);
bool (*checkentry)(const char *table, const void *entry,
const struct xt_target *target, void *targinfo,
unsigned int hook_mask);
void (*destroy)(const struct xt_target *target, void *targinfo);
unsigned int targetsize;
u_int8_t revision;
u_int8_t family;
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_kernel *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;
struct module *me;
};
#define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_replace)-1)) & \
~(__alignof__(struct ebt_replace)-1))
extern struct ebt_table *ebt_register_table(struct net *net,
const struct ebt_table *table);
extern void ebt_unregister_table(struct net *net, struct ebt_table *table);
extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb,
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 (par->hook_mask & (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 (par->hook_mask &= ~(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
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