root/include/linux/netfilter_ipv4.h

INCLUDED FROM

#ifndef __LINUX_IP_NETFILTER_H
#define __LINUX_IP_NETFILTER_H

/* IPv4-specific defines for netfilter. 
 * (C)1998 Rusty Russell -- This code is GPL.
 */

#include <linux/netfilter.h>

/* only for userspace compatibility */
#ifndef __KERNEL__
/* IP Cache bits. */
/* Src IP address. */
#define NFC_IP_SRC              0x0001
/* Dest IP address. */
#define NFC_IP_DST              0x0002
/* Input device. */
#define NFC_IP_IF_IN            0x0004
/* Output device. */
#define NFC_IP_IF_OUT           0x0008
/* TOS. */
#define NFC_IP_TOS              0x0010
/* Protocol. */
#define NFC_IP_PROTO            0x0020
/* IP options. */
#define NFC_IP_OPTIONS          0x0040
/* Frag & flags. */
#define NFC_IP_FRAG             0x0080

/* Per-protocol information: only matters if proto match. */
/* TCP flags. */
#define NFC_IP_TCPFLAGS         0x0100
/* Source port. */
#define NFC_IP_SRC_PT           0x0200
/* Dest port. */
#define NFC_IP_DST_PT           0x0400
/* Something else about the proto */
#define NFC_IP_PROTO_UNKNOWN    0x2000

/* IP Hooks */
/* After promisc drops, checksum checks. */
#define NF_IP_PRE_ROUTING       0
/* If the packet is destined for this box. */
#define NF_IP_LOCAL_IN          1
/* If the packet is destined for another interface. */
#define NF_IP_FORWARD           2
/* Packets coming from a local process. */
#define NF_IP_LOCAL_OUT         3
/* Packets about to hit the wire. */
#define NF_IP_POST_ROUTING      4
#define NF_IP_NUMHOOKS          5
#endif /* ! __KERNEL__ */

enum nf_ip_hook_priorities {
        NF_IP_PRI_FIRST = INT_MIN,
        NF_IP_PRI_CONNTRACK_DEFRAG = -400,
        NF_IP_PRI_RAW = -300,
        NF_IP_PRI_SELINUX_FIRST = -225,
        NF_IP_PRI_CONNTRACK = -200,
        NF_IP_PRI_MANGLE = -150,
        NF_IP_PRI_NAT_DST = -100,
        NF_IP_PRI_FILTER = 0,
        NF_IP_PRI_SECURITY = 50,
        NF_IP_PRI_NAT_SRC = 100,
        NF_IP_PRI_SELINUX_LAST = 225,
        NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX,
        NF_IP_PRI_LAST = INT_MAX,
};

/* Arguments for setsockopt SOL_IP: */
/* 2.0 firewalling went from 64 through 71 (and +256, +512, etc). */
/* 2.2 firewalling (+ masq) went from 64 through 76 */
/* 2.4 firewalling went 64 through 67. */
#define SO_ORIGINAL_DST 80

#ifdef __KERNEL__
extern int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type);
extern int ip_xfrm_me_harder(struct sk_buff *skb);
extern __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
                                   unsigned int dataoff, u_int8_t protocol);
#endif /*__KERNEL__*/

#endif /*__LINUX_IP_NETFILTER_H*/