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      1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
      2 #ifndef _UAPI_X_TABLES_H
      3 #define _UAPI_X_TABLES_H
      4 #include <linux/kernel.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[0];
     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[0];
    123 };
    124 
    125 #define XT_INV_PROTO		0x40	/* Invert the sense of PROTO. */
    126 
    127 #ifndef __KERNEL__
    128 /* fn returns 0 to continue iteration */
    129 #define XT_MATCH_ITERATE(type, e, fn, args...)			\
    130 ({								\
    131 	unsigned int __i;					\
    132 	int __ret = 0;						\
    133 	struct xt_entry_match *__m;				\
    134 								\
    135 	for (__i = sizeof(type);				\
    136 	     __i < (e)->target_offset;				\
    137 	     __i += __m->u.match_size) {			\
    138 		__m = (void *)e + __i;				\
    139 								\
    140 		__ret = fn(__m , ## args);			\
    141 		if (__ret != 0)					\
    142 			break;					\
    143 	}							\
    144 	__ret;							\
    145 })
    146 
    147 /* fn returns 0 to continue iteration */
    148 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
    149 ({								\
    150 	unsigned int __i, __n;					\
    151 	int __ret = 0;						\
    152 	type *__entry;						\
    153 								\
    154 	for (__i = 0, __n = 0; __i < (size);			\
    155 	     __i += __entry->next_offset, __n++) { 		\
    156 		__entry = (void *)(entries) + __i;		\
    157 		if (__n < n)					\
    158 			continue;				\
    159 								\
    160 		__ret = fn(__entry , ## args);			\
    161 		if (__ret != 0)					\
    162 			break;					\
    163 	}							\
    164 	__ret;							\
    165 })
    166 
    167 /* fn returns 0 to continue iteration */
    168 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
    169 	XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
    170 
    171 #endif /* !__KERNEL__ */
    172 
    173 /* pos is normally a struct ipt_entry/ip6t_entry/etc. */
    174 #define xt_entry_foreach(pos, ehead, esize) \
    175 	for ((pos) = (typeof(pos))(ehead); \
    176 	     (pos) < (typeof(pos))((char *)(ehead) + (esize)); \
    177 	     (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
    178 
    179 /* can only be xt_entry_match, so no use of typeof here */
    180 #define xt_ematch_foreach(pos, entry) \
    181 	for ((pos) = (struct xt_entry_match *)entry->elems; \
    182 	     (pos) < (struct xt_entry_match *)((char *)(entry) + \
    183 	             (entry)->target_offset); \
    184 	     (pos) = (struct xt_entry_match *)((char *)(pos) + \
    185 	             (pos)->u.match_size))
    186 
    187 
    188 #endif /* _UAPI_X_TABLES_H */
    189