The C and C++ Include Header Files

/usr/include/linux/netfilter_ipv4.h


$ cat -n /usr/include/linux/netfilter_ipv4.h

     1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
     2	/* IPv4-specific defines for netfilter. 
     3	 * (C)1998 Rusty Russell -- This code is GPL.
     4	 */
     5	#ifndef __LINUX_IP_NETFILTER_H
     6	#define __LINUX_IP_NETFILTER_H
     7	
     8	
     9	#include <linux/netfilter.h>
    10	
    11	/* only for userspace compatibility */
    12	
    13	#include <limits.h> /* for INT_MIN, INT_MAX */
    14	
    15	/* IP Hooks */
    16	/* After promisc drops, checksum checks. */
    17	#define NF_IP_PRE_ROUTING	0
    18	/* If the packet is destined for this box. */
    19	#define NF_IP_LOCAL_IN		1
    20	/* If the packet is destined for another interface. */
    21	#define NF_IP_FORWARD		2
    22	/* Packets coming from a local process. */
    23	#define NF_IP_LOCAL_OUT		3
    24	/* Packets about to hit the wire. */
    25	#define NF_IP_POST_ROUTING	4
    26	#define NF_IP_NUMHOOKS		5
    27	
    28	enum nf_ip_hook_priorities {
    29		NF_IP_PRI_FIRST = INT_MIN,
    30		NF_IP_PRI_RAW_BEFORE_DEFRAG = -450,
    31		NF_IP_PRI_CONNTRACK_DEFRAG = -400,
    32		NF_IP_PRI_RAW = -300,
    33		NF_IP_PRI_SELINUX_FIRST = -225,
    34		NF_IP_PRI_CONNTRACK = -200,
    35		NF_IP_PRI_MANGLE = -150,
    36		NF_IP_PRI_NAT_DST = -100,
    37		NF_IP_PRI_FILTER = 0,
    38		NF_IP_PRI_SECURITY = 50,
    39		NF_IP_PRI_NAT_SRC = 100,
    40		NF_IP_PRI_SELINUX_LAST = 225,
    41		NF_IP_PRI_CONNTRACK_HELPER = 300,
    42		NF_IP_PRI_CONNTRACK_CONFIRM = INT_MAX,
    43		NF_IP_PRI_LAST = INT_MAX,
    44	};
    45	
    46	/* Arguments for setsockopt SOL_IP: */
    47	/* 2.0 firewalling went from 64 through 71 (and +256, +512, etc). */
    48	/* 2.2 firewalling (+ masq) went from 64 through 76 */
    49	/* 2.4 firewalling went 64 through 67. */
    50	#define SO_ORIGINAL_DST 80
    51	
    52	
    53	#endif /* __LINUX_IP_NETFILTER_H */