ebtables.h

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/*
 *  ebtables
 *
 *  Authors:
 *  Bart De Schuymer        <[email protected]>
 *
 *  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 _UAPI__LINUX_BRIDGE_EFF_H
#define _UAPI__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)


/* 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 /* _UAPI__LINUX_BRIDGE_EFF_H */