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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

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 *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 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] __attribute__ ((aligned (__alignof__(struct ebt_replace))));

};

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] __attribute__ ((aligned (__alignof__(struct ebt_replace))));

};

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] __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;

        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] __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];

        /* 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;

        struct module *me;

};

#define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_replace)-1)) & \

                     ~(__alignof__(struct ebt_replace)-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