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The C and C++ Include Header Files

/usr/include/linux/netfilter/x_tables.h


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

     1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
     2	#ifndef _X_TABLES_H
     3	#define _X_TABLES_H
     4	#include <linux/const.h>
     5	#include <linux/types.h>
     6	
     7	#define XT_FUNCTION_MAXNAMELEN 30
     8	#define XT_EXTENSION_MAXNAMELEN 29
     9	#define XT_TABLE_MAXNAMELEN 32
    10	
    11	struct xt_entry_match {
    12		union {
    13			struct {
    14				__u16 match_size;
    15	
    16				/* Used by userspace */
    17				char name[XT_EXTENSION_MAXNAMELEN];
    18				__u8 revision;
    19			} user;
    20			struct {
    21				__u16 match_size;
    22	
    23				/* Used inside the kernel */
    24				struct xt_match *match;
    25			} kernel;
    26	
    27			/* Total length */
    28			__u16 match_size;
    29		} u;
    30	
    31		unsigned char data[];
    32	};
    33	
    34	struct xt_entry_target {
    35		union {
    36			struct {
    37				__u16 target_size;
    38	
    39				/* Used by userspace */
    40				char name[XT_EXTENSION_MAXNAMELEN];
    41				__u8 revision;
    42			} user;
    43			struct {
    44				__u16 target_size;
    45	
    46				/* Used inside the kernel */
    47				struct xt_target *target;
    48			} kernel;
    49	
    50			/* Total length */
    51			__u16 target_size;
    52		} u;
    53	
    54		unsigned char data[0];
    55	};
    56	
    57	#define XT_TARGET_INIT(__name, __size)					       \
    58	{									       \
    59		.target.u.user = {						       \
    60			.target_size	= XT_ALIGN(__size),			       \
    61			.name		= __name,				       \
    62		},								       \
    63	}
    64	
    65	struct xt_standard_target {
    66		struct xt_entry_target target;
    67		int verdict;
    68	};
    69	
    70	struct xt_error_target {
    71		struct xt_entry_target target;
    72		char errorname[XT_FUNCTION_MAXNAMELEN];
    73	};
    74	
    75	/* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
    76	 * kernel supports, if >= revision. */
    77	struct xt_get_revision {
    78		char name[XT_EXTENSION_MAXNAMELEN];
    79		__u8 revision;
    80	};
    81	
    82	/* CONTINUE verdict for targets */
    83	#define XT_CONTINUE 0xFFFFFFFF
    84	
    85	/* For standard target */
    86	#define XT_RETURN (-NF_REPEAT - 1)
    87	
    88	/* this is a dummy structure to find out the alignment requirement for a struct
    89	 * containing all the fundamental data types that are used in ipt_entry,
    90	 * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
    91	 * personal pleasure to remove it -HW
    92	 */
    93	struct _xt_align {
    94		__u8 u8;
    95		__u16 u16;
    96		__u32 u32;
    97		__u64 u64;
    98	};
    99	
   100	#define XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _xt_align))
   101	
   102	/* Standard return verdict, or do jump. */
   103	#define XT_STANDARD_TARGET ""
   104	/* Error verdict. */
   105	#define XT_ERROR_TARGET "ERROR"
   106	
   107	#define SET_COUNTER(c,b,p) do { (c).bcnt = (b); (c).pcnt = (p); } while(0)
   108	#define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
   109	
   110	struct xt_counters {
   111		__u64 pcnt, bcnt;			/* Packet and byte counters */
   112	};
   113	
   114	/* The argument to IPT_SO_ADD_COUNTERS. */
   115	struct xt_counters_info {
   116		/* Which table. */
   117		char name[XT_TABLE_MAXNAMELEN];
   118	
   119		unsigned int num_counters;
   120	
   121		/* The counters (actually `number' of these). */
   122		struct xt_counters counters[];
   123	};
   124	
   125	#define XT_INV_PROTO		0x40	/* Invert the sense of PROTO. */
   126	
   127	/* fn returns 0 to continue iteration */
   128	#define XT_MATCH_ITERATE(type, e, fn, args...)			\
   129	({								\
   130		unsigned int __i;					\
   131		int __ret = 0;						\
   132		struct xt_entry_match *__m;				\
   133									\
   134		for (__i = sizeof(type);				\
   135		     __i < (e)->target_offset;				\
   136		     __i += __m->u.match_size) {			\
   137			__m = (void *)e + __i;				\
   138									\
   139			__ret = fn(__m , ## args);			\
   140			if (__ret != 0)					\
   141				break;					\
   142		}							\
   143		__ret;							\
   144	})
   145	
   146	/* fn returns 0 to continue iteration */
   147	#define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
   148	({								\
   149		unsigned int __i, __n;					\
   150		int __ret = 0;						\
   151		type *__entry;						\
   152									\
   153		for (__i = 0, __n = 0; __i < (size);			\
   154		     __i += __entry->next_offset, __n++) { 		\
   155			__entry = (void *)(entries) + __i;		\
   156			if (__n < n)					\
   157				continue;				\
   158									\
   159			__ret = fn(__entry , ## args);			\
   160			if (__ret != 0)					\
   161				break;					\
   162		}							\
   163		__ret;							\
   164	})
   165	
   166	/* fn returns 0 to continue iteration */
   167	#define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
   168		XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
   169	
   170	
   171	/* pos is normally a struct ipt_entry/ip6t_entry/etc. */
   172	#define xt_entry_foreach(pos, ehead, esize) \
   173		for ((pos) = (typeof(pos))(ehead); \
   174		     (pos) < (typeof(pos))((char *)(ehead) + (esize)); \
   175		     (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
   176	
   177	/* can only be xt_entry_match, so no use of typeof here */
   178	#define xt_ematch_foreach(pos, entry) \
   179		for ((pos) = (struct xt_entry_match *)entry->elems; \
   180		     (pos) < (struct xt_entry_match *)((char *)(entry) + \
   181		             (entry)->target_offset); \
   182		     (pos) = (struct xt_entry_match *)((char *)(pos) + \
   183		             (pos)->u.match_size))
   184	
   185	
   186	#endif /* _X_TABLES_H */