include/uapi/linux/netfilter/x_tables.h

   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 */