ip_tables.h

Go to the documentation of this file.

/*
 * 25-Jul-1998 Major changes to allow for ip chain table
 *
 * 3-Jan-2000 Named tables to allow packet selection for different uses.
 */

/*
 *  Format of an IP firewall descriptor
 *
 *  src, dst, src_mask, dst_mask are always stored in network byte order.
 *  flags are stored in host byte order (of course).
 *  Port numbers are stored in HOST byte order.
 */
#ifndef _IPTABLES_H
#define _IPTABLES_H

#include <linux/if.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/skbuff.h>

#include <linux/init.h>
#include <uapi/linux/netfilter_ipv4/ip_tables.h>

extern void ipt_init(void) __init;

extern struct xt_table *ipt_register_table(struct net *net,
                       const struct xt_table *table,
                       const struct ipt_replace *repl);
extern void ipt_unregister_table(struct net *net, struct xt_table *table);

/* Standard entry. */
struct ipt_standard {
    struct ipt_entry entry;
    struct xt_standard_target target;
};

struct ipt_error {
    struct ipt_entry entry;
    struct xt_error_target target;
};

#define IPT_ENTRY_INIT(__size)                             \
{                                          \
    .target_offset  = sizeof(struct ipt_entry),                \
    .next_offset    = (__size),                        \
}

#define IPT_STANDARD_INIT(__verdict)                           \
{                                          \
    .entry      = IPT_ENTRY_INIT(sizeof(struct ipt_standard)),         \
    .target     = XT_TARGET_INIT(XT_STANDARD_TARGET,               \
                     sizeof(struct xt_standard_target)),   \
    .target.verdict = -(__verdict) - 1,                    \
}

#define IPT_ERROR_INIT                                 \
{                                          \
    .entry      = IPT_ENTRY_INIT(sizeof(struct ipt_error)),        \
    .target     = XT_TARGET_INIT(XT_ERROR_TARGET,              \
                     sizeof(struct xt_error_target)),      \
    .target.errorname = "ERROR",                           \
}

extern void *ipt_alloc_initial_table(const struct xt_table *);
extern unsigned int ipt_do_table(struct sk_buff *skb,
                 unsigned int hook,
                 const struct net_device *in,
                 const struct net_device *out,
                 struct xt_table *table);

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

struct compat_ipt_entry {
    struct ipt_ip ip;
    compat_uint_t nfcache;
    __u16 target_offset;
    __u16 next_offset;
    compat_uint_t comefrom;
    struct compat_xt_counters counters;
    unsigned char elems[0];
};

/* Helper functions */
static inline struct xt_entry_target *
compat_ipt_get_target(struct compat_ipt_entry *e)
{
    return (void *)e + e->target_offset;
}

#endif /* CONFIG_COMPAT */
#endif /* _IPTABLES_H */