include/linux/netfilter/x_tables.h

   1 #ifndef _X_TABLES_H
   2 #define _X_TABLES_H
   3
   4 #define XT_FUNCTION_MAXNAMELEN 30
   5 #define XT_TABLE_MAXNAMELEN 32
   6
   7 struct xt_entry_match
   8 {
   9         union {
  10                 struct {
  11                         u_int16_t match_size;
  12
  13                         /* Used by userspace */
  14                         char name[XT_FUNCTION_MAXNAMELEN-1];
  15
  16                         u_int8_t revision;
  17                 } user;
  18                 struct {
  19                         u_int16_t match_size;
  20
  21                         /* Used inside the kernel */
  22                         struct xt_match *match;
  23                 } kernel;
  24
  25                 /* Total length */
  26                 u_int16_t match_size;
  27         } u;
  28
  29         unsigned char data[0];
  30 };
  31
  32 struct xt_entry_target
  33 {
  34         union {
  35                 struct {
  36                         u_int16_t target_size;
  37
  38                         /* Used by userspace */
  39                         char name[XT_FUNCTION_MAXNAMELEN-1];
  40
  41                         u_int8_t revision;
  42                 } user;
  43                 struct {
  44                         u_int16_t target_size;
  45
  46                         /* Used inside the kernel */
  47                         struct xt_target *target;
  48                 } kernel;
  49
  50                 /* Total length */
  51                 u_int16_t 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 {
  67         struct xt_entry_target target;
  68         int verdict;
  69 };
  70
  71 /* The argument to IPT_SO_GET_REVISION_*.  Returns highest revision
  72  * kernel supports, if >= revision. */
  73 struct xt_get_revision
  74 {
  75         char name[XT_FUNCTION_MAXNAMELEN-1];
  76
  77         u_int8_t revision;
  78 };
  79
  80 /* CONTINUE verdict for targets */
  81 #define XT_CONTINUE 0xFFFFFFFF
  82
  83 /* For standard target */
  84 #define XT_RETURN (-NF_REPEAT - 1)
  85
  86 /* this is a dummy structure to find out the alignment requirement for a struct
  87  * containing all the fundamental data types that are used in ipt_entry,
  88  * ip6t_entry and arpt_entry.  This sucks, and it is a hack.  It will be my
  89  * personal pleasure to remove it -HW
  90  */
  91 struct _xt_align
  92 {
  93         u_int8_t u8;
  94         u_int16_t u16;
  95         u_int32_t u32;
  96         u_int64_t u64;
  97 };
  98
  99 #define XT_ALIGN(s) (((s) + (__alignof__(struct _xt_align)-1))  \
 100                         & ~(__alignof__(struct _xt_align)-1))
 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 {
 112         u_int64_t pcnt, bcnt;                   /* Packet and byte counters */
 113 };
 114
 115 /* The argument to IPT_SO_ADD_COUNTERS. */
 116 struct xt_counters_info
 117 {
 118         /* Which table. */
 119         char name[XT_TABLE_MAXNAMELEN];
 120
 121         unsigned int num_counters;
 122
 123         /* The counters (actually `number' of these). */
 124         struct xt_counters counters[0];
 125 };
 126
 127 #define XT_INV_PROTO            0x40    /* Invert the sense of PROTO. */
 128
 129 /* fn returns 0 to continue iteration */
 130 #define XT_MATCH_ITERATE(type, e, fn, args...)                  \
 131 ({                                                              \
 132         unsigned int __i;                                       \
 133         int __ret = 0;                                          \
 134         struct xt_entry_match *__m;                             \
 135                                                                 \
 136         for (__i = sizeof(type);                                \
 137              __i < (e)->target_offset;                          \
 138              __i += __m->u.match_size) {                        \
 139                 __m = (void *)e + __i;                          \
 140                                                                 \
 141                 __ret = fn(__m , ## args);                      \
 142                 if (__ret != 0)                                 \
 143                         break;                                  \
 144         }                                                       \
 145         __ret;                                                  \
 146 })
 147
 148 /* fn returns 0 to continue iteration */
 149 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
 150 ({                                                              \
 151         unsigned int __i, __n;                                  \
 152         int __ret = 0;                                          \
 153         type *__entry;                                          \
 154                                                                 \
 155         for (__i = 0, __n = 0; __i < (size);                    \
 156              __i += __entry->next_offset, __n++) {              \
 157                 __entry = (void *)(entries) + __i;              \
 158                 if (__n < n)                                    \
 159                         continue;                               \
 160                                                                 \
 161                 __ret = fn(__entry , ## args);                  \
 162                 if (__ret != 0)                                 \
 163                         break;                                  \
 164         }                                                       \
 165         __ret;                                                  \
 166 })
 167
 168 /* fn returns 0 to continue iteration */
 169 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
 170         XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
 171
 172
 173 #endif /* _X_TABLES_H */