root/include/linux/netfilter_bridge.h

INCLUDED FROM

DEFINITIONS

1. nf_bridge_maybe_copy_header
2. nf_bridge_encap_header_len
3. nf_bridge_pad

#ifndef __LINUX_BRIDGE_NETFILTER_H
#define __LINUX_BRIDGE_NETFILTER_H

/* bridge-specific defines for netfilter. 
 */

#include <linux/netfilter.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/if_pppox.h>

/* Bridge Hooks */
/* After promisc drops, checksum checks. */
#define NF_BR_PRE_ROUTING       0
/* If the packet is destined for this box. */
#define NF_BR_LOCAL_IN          1
/* If the packet is destined for another interface. */
#define NF_BR_FORWARD           2
/* Packets coming from a local process. */
#define NF_BR_LOCAL_OUT         3
/* Packets about to hit the wire. */
#define NF_BR_POST_ROUTING      4
/* Not really a hook, but used for the ebtables broute table */
#define NF_BR_BROUTING          5
#define NF_BR_NUMHOOKS          6

#ifdef __KERNEL__

enum nf_br_hook_priorities {
        NF_BR_PRI_FIRST = INT_MIN,
        NF_BR_PRI_NAT_DST_BRIDGED = -300,
        NF_BR_PRI_FILTER_BRIDGED = -200,
        NF_BR_PRI_BRNF = 0,
        NF_BR_PRI_NAT_DST_OTHER = 100,
        NF_BR_PRI_FILTER_OTHER = 200,
        NF_BR_PRI_NAT_SRC = 300,
        NF_BR_PRI_LAST = INT_MAX,
};

#ifdef CONFIG_BRIDGE_NETFILTER

#define BRNF_PKT_TYPE                   0x01
#define BRNF_BRIDGED_DNAT               0x02
#define BRNF_DONT_TAKE_PARENT           0x04
#define BRNF_BRIDGED                    0x08
#define BRNF_NF_BRIDGE_PREROUTING       0x10


/* Only used in br_forward.c */
extern int nf_bridge_copy_header(struct sk_buff *skb);
static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
{
        if (skb->nf_bridge &&
            skb->nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT))
                return nf_bridge_copy_header(skb);
        return 0;
}

static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
{
        switch (skb->protocol) {
        case __constant_htons(ETH_P_8021Q):
                return VLAN_HLEN;
        case __constant_htons(ETH_P_PPP_SES):
                return PPPOE_SES_HLEN;
        default:
                return 0;
        }
}

/* This is called by the IP fragmenting code and it ensures there is
 * enough room for the encapsulating header (if there is one). */
static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
{
        if (skb->nf_bridge)
                return nf_bridge_encap_header_len(skb);
        return 0;
}

struct bridge_skb_cb {
        union {
                __be32 ipv4;
        } daddr;
};

#else
#define nf_bridge_maybe_copy_header(skb)        (0)
#define nf_bridge_pad(skb)                      (0)
#endif /* CONFIG_BRIDGE_NETFILTER */

#endif /* __KERNEL__ */
#endif