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The C and C++ Include Header Files

/usr/include/linux/netfilter.h


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

     1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
     2	#ifndef __LINUX_NETFILTER_H
     3	#define __LINUX_NETFILTER_H
     4	
     5	#include <linux/types.h>
     6	
     7	#include <linux/in.h>
     8	#include <linux/in6.h>
     9	
    10	/* Responses from hook functions. */
    11	#define NF_DROP 0
    12	#define NF_ACCEPT 1
    13	#define NF_STOLEN 2
    14	#define NF_QUEUE 3
    15	#define NF_REPEAT 4
    16	#define NF_STOP 5	/* Deprecated, for userspace nf_queue compatibility. */
    17	#define NF_MAX_VERDICT NF_STOP
    18	
    19	/* we overload the higher bits for encoding auxiliary data such as the queue
    20	 * number or errno values. Not nice, but better than additional function
    21	 * arguments. */
    22	#define NF_VERDICT_MASK 0x000000ff
    23	
    24	/* extra verdict flags have mask 0x0000ff00 */
    25	#define NF_VERDICT_FLAG_QUEUE_BYPASS	0x00008000
    26	
    27	/* queue number (NF_QUEUE) or errno (NF_DROP) */
    28	#define NF_VERDICT_QMASK 0xffff0000
    29	#define NF_VERDICT_QBITS 16
    30	
    31	#define NF_QUEUE_NR(x) ((((x) << 16) & NF_VERDICT_QMASK) | NF_QUEUE)
    32	
    33	#define NF_DROP_ERR(x) (((-x) << 16) | NF_DROP)
    34	
    35	/* only for userspace compatibility */
    36	
    37	/* NF_VERDICT_BITS should be 8 now, but userspace might break if this changes */
    38	#define NF_VERDICT_BITS 16
    39	
    40	enum nf_inet_hooks {
    41		NF_INET_PRE_ROUTING,
    42		NF_INET_LOCAL_IN,
    43		NF_INET_FORWARD,
    44		NF_INET_LOCAL_OUT,
    45		NF_INET_POST_ROUTING,
    46		NF_INET_NUMHOOKS,
    47		NF_INET_INGRESS = NF_INET_NUMHOOKS,
    48	};
    49	
    50	enum nf_dev_hooks {
    51		NF_NETDEV_INGRESS,
    52		NF_NETDEV_EGRESS,
    53		NF_NETDEV_NUMHOOKS
    54	};
    55	
    56	enum {
    57		NFPROTO_UNSPEC =  0,
    58		NFPROTO_INET   =  1,
    59		NFPROTO_IPV4   =  2,
    60		NFPROTO_ARP    =  3,
    61		NFPROTO_NETDEV =  5,
    62		NFPROTO_BRIDGE =  7,
    63		NFPROTO_IPV6   = 10,
    64		NFPROTO_DECNET = 12,
    65		NFPROTO_NUMPROTO,
    66	};
    67	
    68	union nf_inet_addr {
    69		__u32		all[4];
    70		__be32		ip;
    71		__be32		ip6[4];
    72		struct in_addr	in;
    73		struct in6_addr	in6;
    74	};
    75	
    76	#endif /* __LINUX_NETFILTER_H */